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Lavilla-Puerta M, Latter R, Bellè F, Cervelli T, Galli A, Perata P, Chini A, Flashman E, Giuntoli B. Identification of novel plant cysteine oxidase inhibitors from a yeast chemical genetic screen. J Biol Chem 2023; 299:105366. [PMID: 37863264 PMCID: PMC10692734 DOI: 10.1016/j.jbc.2023.105366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/28/2023] [Accepted: 10/11/2023] [Indexed: 10/22/2023] Open
Abstract
Hypoxic responses in plants involve Plant Cysteine Oxidases (PCOs). They catalyze the N-terminal cysteine oxidation of Ethylene Response Factors VII (ERF-VII) in an oxygen-dependent manner, leading to their degradation via the cysteine N-degron pathway (Cys-NDP) in normoxia. In hypoxia, PCO activity drops, leading to the stabilization of ERF-VIIs and subsequent hypoxic gene upregulation. Thus far, no chemicals have been described to specifically inhibit PCO enzymes. In this work, we devised an in vivo pipeline to discover Cys-NDP effector molecules. Budding yeast expressing AtPCO4 and plant-based ERF-VII reporters was deployed to screen a library of natural-like chemical scaffolds and was further combined with an Arabidopsis Cys-NDP reporter line. This strategy allowed us to identify three PCO inhibitors, two of which were shown to affect PCO activity in vitro. Application of these molecules to Arabidopsis seedlings led to an increase in ERF-VII stability, induction of anaerobic gene expression, and improvement of tolerance to anoxia. By combining a high-throughput heterologous platform and the plant model Arabidopsis, our synthetic pipeline provides a versatile system to study how the Cys-NDP is modulated. Its first application here led to the discovery of at least two hypoxia-mimicking molecules with the potential to impact plant tolerance to low oxygen stress.
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Affiliation(s)
| | - Rebecca Latter
- Department of Chemistry, University of Oxford, Oxford, UK
| | | | | | | | | | - Andrea Chini
- Department of Plant Molecular Genetics, Centro Nacional de Biotecnología, CSIC, Madrid, Spain
| | | | - Beatrice Giuntoli
- Plantlab, Center of Plant Sciences, Scuola Superiore Sant'Anna, Pisa, Italy; Biology Department, University of Pisa, Pisa, Italy.
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2
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Jones JT, Morelli KA, Vesely EM, Puerner CTS, Pavuluri CK, Ross BS, van Rhijn N, Bromley MJ, Cramer RA. The cystic fibrosis treatment Trikafta affects the growth, viability, and cell wall of Aspergillus fumigatus biofilms. mBio 2023; 14:e0151623. [PMID: 37830825 PMCID: PMC10653927 DOI: 10.1128/mbio.01516-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 09/01/2023] [Indexed: 10/14/2023] Open
Abstract
IMPORTANCE PwCF commonly test positive for pathogenic fungi, and more than 90% of the cystic fibrosis patient population is approved for the modulator treatment, Trikafta. Therefore, it is critical to understand how fungal communities, specifically A. fumigatus, respond to Trikafta exposure. Therefore, we sought to determine whether Trikafta impacted the biology of A. fumigatus biofilms. Our data demonstrate that Trikafta reduces biomass in several laboratory strains as well as clinical strains isolated from the expectorated sputum of pwCF. Furthermore, Trikafta reduces fungal viability and the capacity of biofilms to recover following treatment. Of particular importance, Trikafta affects how A. fumigatus biofilms respond to cell wall stressors, suggesting that Trikafta modulates components of the cell wall. Since the cell wall directly affects how a host immune system will respond to and effectively neutralize pathogens, our work, demonstrating that Trikafta impacts the A. fumigatus cell wall, is potentially highly relevant to fungal-induced disease pathogenesis.
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Affiliation(s)
- Jane T. Jones
- Department of Microbiology and Immunology, Dartmouth Geisel School of Medicine, Hanover, New Hampshire, USA
| | - Kaesi A. Morelli
- Department of Microbiology and Immunology, Dartmouth Geisel School of Medicine, Hanover, New Hampshire, USA
| | - Elisa M. Vesely
- Department of Microbiology and Immunology, Dartmouth Geisel School of Medicine, Hanover, New Hampshire, USA
| | - Charles T. S. Puerner
- Department of Microbiology and Immunology, Dartmouth Geisel School of Medicine, Hanover, New Hampshire, USA
| | - Chetan K. Pavuluri
- Department of Microbiology and Immunology, Dartmouth Geisel School of Medicine, Hanover, New Hampshire, USA
| | - Brandon S. Ross
- Department of Microbiology and Immunology, Dartmouth Geisel School of Medicine, Hanover, New Hampshire, USA
| | - Norman van Rhijn
- Manchester Fungal Infection Group, Division of Evolution, Infection, and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Antimicrobial Resistance Network, University of Manchester, Manchester, United Kingdom
| | - Michael J. Bromley
- Manchester Fungal Infection Group, Division of Evolution, Infection, and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Antimicrobial Resistance Network, University of Manchester, Manchester, United Kingdom
| | - Robert A. Cramer
- Department of Microbiology and Immunology, Dartmouth Geisel School of Medicine, Hanover, New Hampshire, USA
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3
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Beattie SR, Krysan DJ. A Dual-Readout High-Throughput Screening Assay for Small Molecules Active Against Aspergillus Fumigatus. Methods Mol Biol 2023; 2658:35-42. [PMID: 37024693 DOI: 10.1007/978-1-0716-3155-3_3] [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: 04/08/2023]
Abstract
Human fungal infections caused by molds have been on the rise in recent years. These infections have high mortality rates compared to other fungal infections, and yet treatment options are limited due to resistance to clinical antifungals and lack of broad-spectrum activity against molds. Technical challenges associated with molds have limited large-throughput screening efforts for anti-mold compounds: therefore, we adapted an assay for use with A. fumigatus to help fill the gap in robust screening platforms for these organisms. This assay measures the release of the cytosolic enzyme adenylate kinase (AK) as a measure of fungal cell lysis and can also detect inhibition of germination as a reduction in the secretion of AK during vegetative growth. The ability to detect both lysis and inhibition of germination facilitates the identification of a wide range of compounds with different mechanisms of action, creating a strong screening platform for the identification of novel, anti-mold compounds.
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Affiliation(s)
- Sarah R Beattie
- Departments of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
| | - Damian J Krysan
- Departments of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
- Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
- Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
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4
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Impaired amino acid uptake leads to global metabolic imbalance of Candida albicans biofilms. NPJ Biofilms Microbiomes 2022; 8:78. [PMID: 36224215 PMCID: PMC9556537 DOI: 10.1038/s41522-022-00341-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 09/23/2022] [Indexed: 12/01/2022] Open
Abstract
Candida albicans biofilm maturation is accompanied by enhanced expression of amino acid acquisition genes. Three state-of-the-art omics techniques were applied to detail the importance of active amino acid uptake during biofilm development. Comparative analyses of normoxic wild-type biofilms were performed under three metabolically challenging conditions: aging, hypoxia, and disabled amino acid uptake using a strain lacking the regulator of amino acid permeases Stp2. Aging-induced amino acid acquisition and stress responses to withstand the increasingly restricted environment. Hypoxia paralyzed overall energy metabolism with delayed amino acid consumption, but following prolonged adaptation, the metabolic fingerprints aligned with aged normoxic biofilms. The extracellular metabolome of stp2Δ biofilms revealed deficient uptake for 11 amino acids, resulting in extensive transcriptional and metabolic changes including induction of amino acid biosynthesis and carbohydrate and micronutrient uptake. Altogether, this study underscores the critical importance of a balanced amino acid homeostasis for C. albicans biofilm development.
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5
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Das R, Kotra K, Singh P, Loh B, Leptihn S, Bajpai U. Alternative Treatment Strategies for Secondary Bacterial and Fungal Infections Associated with COVID-19. Infect Dis Ther 2022; 11:53-78. [PMID: 34807451 PMCID: PMC8607056 DOI: 10.1007/s40121-021-00559-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 10/21/2021] [Indexed: 01/08/2023] Open
Abstract
Antimicrobials are essential for combating infectious diseases. However, an increase in resistance to them is a major cause of concern. The empirical use of drugs in managing COVID-19 and the associated secondary infections have further exacerbated the problem of antimicrobial resistance. Hence, the situation mandates exploring and developing efficient alternatives for the treatment of bacterial and fungal infections in patients suffering from COVID-19 or other viral infections. In this review, we have described the alternatives to conventional antimicrobials that have shown promising results and are at various stages of development. An acceleration of efforts to investigate their potential as therapeutics can provide more treatment options for clinical management of drug-resistant secondary bacterial and fungal infections in the current pandemic and similar potential outbreaks in the future. The alternatives include bacteriophages and their lytic enzymes, anti-fungal enzymes, antimicrobial peptides, nanoparticles and small molecule inhibitors among others. What is required at this stage is to critically examine the challenges in developing the listed compounds and biomolecules as therapeutics and to establish guidelines for their safe and effective application within a suitable time frame. In this review, we have attempted to highlight the importance of rational use of antimicrobials in patients suffering from COVID-19 and boost the deployment of alternative therapeutics.
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Affiliation(s)
- Ritam Das
- Department of Life Science, Acharya Narendra Dev College, University of Delhi, New Delhi, 110019 India
| | - Komal Kotra
- Department of Zoology, Acharya Narendra Dev College, University of Delhi, New Delhi, 110019 India
| | - Pulkit Singh
- Department of Zoology, Acharya Narendra Dev College, University of Delhi, New Delhi, 110019 India
| | - Belinda Loh
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 314400 People’s Republic of China
| | - Sebastian Leptihn
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 314400 People’s Republic of China
| | - Urmi Bajpai
- Department of Biomedical Science, Acharya Narendra Dev College, University of Delhi, Govindpuri, Kalkaji, New Delhi, 110019 India
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6
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Grosfeld EV, Bidiuk VA, Mitkevich OV, Ghazy ESMO, Kushnirov VV, Alexandrov AI. A Systematic Survey of Characteristic Features of Yeast Cell Death Triggered by External Factors. J Fungi (Basel) 2021; 7:886. [PMID: 34829175 PMCID: PMC8626022 DOI: 10.3390/jof7110886] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/15/2021] [Accepted: 10/17/2021] [Indexed: 12/20/2022] Open
Abstract
Cell death in response to distinct stimuli can manifest different morphological traits. It also depends on various cell death signaling pathways, extensively characterized in higher eukaryotes but less so in microorganisms. The study of cell death in yeast, and specifically Saccharomyces cerevisiae, can potentially be productive for understanding cell death, since numerous killing stimuli have been characterized for this organism. Here, we systematized the literature on external treatments that kill yeast, and which contains at least minimal data on cell death mechanisms. Data from 707 papers from the 7000 obtained using keyword searches were used to create a reference table for filtering types of cell death according to commonly assayed parameters. This table provides a resource for orientation within the literature; however, it also highlights that the common view of similarity between non-necrotic death in yeast and apoptosis in mammals has not provided sufficient progress to create a clear classification of cell death types. Differences in experimental setups also prevent direct comparison between different stimuli. Thus, side-by-side comparisons of various cell death-inducing stimuli under comparable conditions using existing and novel markers that can differentiate between types of cell death seem like a promising direction for future studies.
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Affiliation(s)
- Erika V. Grosfeld
- Moscow Institute of Physics and Technology, 9 Institutskiy per, Dolgoprudny, 141700 Moscow, Russia;
- Federal Research Center of Biotechnology of the RAS, Bach Institute of Biochemistry, 119071 Moscow, Russia; (V.A.B.); (O.V.M.); (E.S.M.O.G.); (V.V.K.)
| | - Victoria A. Bidiuk
- Federal Research Center of Biotechnology of the RAS, Bach Institute of Biochemistry, 119071 Moscow, Russia; (V.A.B.); (O.V.M.); (E.S.M.O.G.); (V.V.K.)
| | - Olga V. Mitkevich
- Federal Research Center of Biotechnology of the RAS, Bach Institute of Biochemistry, 119071 Moscow, Russia; (V.A.B.); (O.V.M.); (E.S.M.O.G.); (V.V.K.)
| | - Eslam S. M. O. Ghazy
- Federal Research Center of Biotechnology of the RAS, Bach Institute of Biochemistry, 119071 Moscow, Russia; (V.A.B.); (O.V.M.); (E.S.M.O.G.); (V.V.K.)
- Institute of Biochemical Technology and Nanotechnology, Peoples’ Friendship University of Russia (RUDN), 6 Miklukho-Maklaya Street, 117198 Moscow, Russia
- Department of Microbiology, Faculty of Pharmacy, Tanta University, Tanta 31111, Egypt
| | - Vitaliy V. Kushnirov
- Federal Research Center of Biotechnology of the RAS, Bach Institute of Biochemistry, 119071 Moscow, Russia; (V.A.B.); (O.V.M.); (E.S.M.O.G.); (V.V.K.)
| | - Alexander I. Alexandrov
- Federal Research Center of Biotechnology of the RAS, Bach Institute of Biochemistry, 119071 Moscow, Russia; (V.A.B.); (O.V.M.); (E.S.M.O.G.); (V.V.K.)
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7
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Caldara M, Marmiroli N. Antimicrobial Properties of Antidepressants and Antipsychotics-Possibilities and Implications. Pharmaceuticals (Basel) 2021; 14:ph14090915. [PMID: 34577614 PMCID: PMC8470654 DOI: 10.3390/ph14090915] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 09/03/2021] [Accepted: 09/08/2021] [Indexed: 12/13/2022] Open
Abstract
The spreading of antibiotic resistance is responsible annually for over 700,000 deaths worldwide, and the prevision is that this number will increase exponentially. The identification of new antimicrobial treatments is a challenge that requires scientists all over the world to collaborate. Developing new drugs is an extremely long and costly process, but it could be paralleled by drug repositioning. The latter aims at identifying new clinical targets of an “old” drug that has already been tested, approved, and even marketed. This approach is very intriguing as it could reduce costs and speed up approval timelines, since data from preclinical studies and on pharmacokinetics, pharmacodynamics, and toxicity are already available. Antidepressants and antipsychotics have been described to inhibit planktonic and sessile growth of different yeasts and bacteria. The main findings in the field are discussed in this critical review, along with the description of the possible microbial targets of these molecules. Considering their antimicrobial activity, the manuscript highlights important implications that the administration of antidepressants and antipsychotics may have on the gut microbiome.
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Affiliation(s)
- Marina Caldara
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy;
- Interdepartmental Center SITEIA.PARMA, University of Parma, Parco Area delle Scienze 181/A, 43124 Parma, Italy
- Correspondence:
| | - Nelson Marmiroli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy;
- Interdepartmental Center SITEIA.PARMA, University of Parma, Parco Area delle Scienze 181/A, 43124 Parma, Italy
- Italian National Interuniversity Consortium for Environmental Sciences (CINSA), University of Parma, 43124 Parma, Italy
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8
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A Unique Dual-Readout High-Throughput Screening Assay To Identify Antifungal Compounds with Aspergillus fumigatus. mSphere 2021; 6:e0053921. [PMID: 34406854 PMCID: PMC8386399 DOI: 10.1128/msphere.00539-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Treatment of invasive mold infections is limited by the lack of adequate drug options that are effective against these fatal infections. High-throughput screening of molds using traditional antifungal assays of growth is problematic and has greatly limited our ability to identify new mold-active agents. Here, we present a high-throughput screening platform for use with Aspergillus fumigatus, the most common causative agent of invasive mold infections, for the discovery of novel mold-active antifungals. This assay detects cell lysis through the release of the cytosolic enzyme adenylate kinase and, thus, is not dependent on changes in biomass or metabolism to detect antifungal activity. The ability to specifically detect cell lysis is a unique aspect of this assay that allows identification of molecules that disrupt fungal cell integrity, such as cell wall-active molecules. We also found that germinating A. fumigatus conidia release low levels of adenylate kinase and that a reduction in this background allowed us to identify molecules that inhibit conidial germination, expanding the potential for discovery of novel antifungal compounds. Here, we describe the validation of this assay and proof-of-concept pilot screens that identified a novel antifungal compound, PIK-75, that disrupts cell wall integrity. This screening assay provides a novel platform for high-throughput screens with A. fumigatus for the identification of anti-mold drugs. IMPORTANCE Fungal infections caused by molds have the highest mortality rates of human fungal infections. These devastating infections are hard to treat and available antifungal drugs are often not effective. Therefore, the identification of new antifungal drugs with mold activity is critical. Drug screening with molds is challenging and there are limited assays available to identify new antifungal compounds directly with these organisms. Here, we present an assay suitable for use for high-throughput screening with a common mold pathogen. This assay has exciting future potential for the identification of new drugs to treat these fatal infections.
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9
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Dishman AF, He J, Volkman BF, Huppler AR. Metamorphic Protein Folding Encodes Multiple Anti- Candida Mechanisms in XCL1. Pathogens 2021; 10:pathogens10060762. [PMID: 34204234 PMCID: PMC8235156 DOI: 10.3390/pathogens10060762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/08/2021] [Accepted: 06/12/2021] [Indexed: 11/16/2022] Open
Abstract
Candida species cause serious infections requiring prolonged and sometimes toxic therapy. Antimicrobial proteins, such as chemokines, hold great interest as potential additions to the small number of available antifungal drugs. Metamorphic proteins reversibly switch between multiple different folded structures. XCL1 is a metamorphic, antimicrobial chemokine that interconverts between the conserved chemokine fold (an α–β monomer) and an alternate fold (an all-β dimer). Previous work has shown that human XCL1 kills C. albicans but has not assessed whether one or both XCL1 folds perform this activity. Here, we use structurally locked engineered XCL1 variants and Candida killing assays, adenylate kinase release assays, and propidium iodide uptake assays to demonstrate that both XCL1 folds kill Candida, but they do so via different mechanisms. Our results suggest that the alternate fold kills via membrane disruption, consistent with previous work, and the chemokine fold does not. XCL1 fold-switching thus provides a mechanism to regulate the XCL1 mode of antifungal killing, which could protect surrounding tissue from damage associated with fungal membrane disruption and could allow XCL1 to overcome candidal resistance by switching folds. This work provides inspiration for the future design of switchable, multifunctional antifungal therapeutics.
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Affiliation(s)
- Acacia F. Dishman
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA;
- Medical Scientist Training Program, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Jie He
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI 53226, USA;
| | - Brian F. Volkman
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA;
- Correspondence: (B.F.V.); (A.R.H.)
| | - Anna R. Huppler
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI 53226, USA;
- Correspondence: (B.F.V.); (A.R.H.)
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10
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Beattie SR, Krysan DJ. Antifungal drug screening: thinking outside the box to identify novel antifungal scaffolds. Curr Opin Microbiol 2020; 57:1-6. [PMID: 32339892 PMCID: PMC7652037 DOI: 10.1016/j.mib.2020.03.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/03/2020] [Accepted: 03/10/2020] [Indexed: 02/07/2023]
Abstract
Invasive fungal infections are responsible for a significant disease burden worldwide. Drugs to treat these infections are limited to only four unique classes, and despite these available treatments, mortality rates remain unacceptably high. In this review, we will discuss antifungal drug screening and how the approach to identifying novel compounds needs move away from traditional growth-based assays in order to meet the demand for new drugs. We highlight specific examples of creative screening strategies that increase the likelihood of identifying compounds with desired activities and provide perspective to inspire development of novel screens for the identification of first-in-class antifungals.
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Affiliation(s)
- Sarah R Beattie
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Damian J Krysan
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA, United States; Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA, United States.
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11
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Kaul G, Shukla M, Dasgupta A, Chopra S. Update on drug-repurposing: is it useful for tackling antimicrobial resistance? Future Microbiol 2019; 14:829-831. [DOI: 10.2217/fmb-2019-0122] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Grace Kaul
- Division of Microbiology, CSIR-Central Drug Research Institute, Sector 10, Janakipuram Extension, Sitapur Road, Lucknow-226031, Uttar Pradesh, India
| | - Manjulika Shukla
- Division of Microbiology, CSIR-Central Drug Research Institute, Sector 10, Janakipuram Extension, Sitapur Road, Lucknow-226031, Uttar Pradesh, India
| | - Arunava Dasgupta
- Division of Microbiology, CSIR-Central Drug Research Institute, Sector 10, Janakipuram Extension, Sitapur Road, Lucknow-226031, Uttar Pradesh, India
| | - Sidharth Chopra
- Division of Microbiology, CSIR-Central Drug Research Institute, Sector 10, Janakipuram Extension, Sitapur Road, Lucknow-226031, Uttar Pradesh, India
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12
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Farha MA, Brown ED. Drug repurposing for antimicrobial discovery. Nat Microbiol 2019; 4:565-577. [PMID: 30833727 DOI: 10.1038/s41564-019-0357-1] [Citation(s) in RCA: 189] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 01/03/2019] [Indexed: 12/17/2022]
Abstract
Antimicrobial resistance continues to be a public threat on a global scale. The ongoing need to develop new antimicrobial drugs that are effective against multi-drug-resistant pathogens has spurred the research community to invest in various drug discovery strategies, one of which is drug repurposing-the process of finding new uses for existing drugs. While still nascent in the antimicrobial field, the approach is gaining traction in both the public and private sector. While the approach has particular promise in fast-tracking compounds into clinical studies, it nevertheless has substantial obstacles to success. This Review covers the art of repurposing existing drugs for antimicrobial purposes. We discuss enabling screening platforms for antimicrobial discovery and present encouraging findings of novel antimicrobial therapeutic strategies. Also covered are general advantages of repurposing over de novo drug development and challenges of the strategy, including scientific, intellectual property and regulatory issues.
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Affiliation(s)
- Maya A Farha
- Michael G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Eric D Brown
- Michael G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.
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Abstract
Invasive fungal infections continue to appear in record numbers as the immunocompromised population of the world increases, owing partially to the increased number of individuals who are infected with HIV and partially to the successful treatment of serious underlying diseases. The effectiveness of current antifungal therapies - polyenes, flucytosine, azoles and echinocandins (as monotherapies or in combinations for prophylaxis, or as empiric, pre-emptive or specific therapies) - in the management of these infections has plateaued. Although these drugs are clinically useful, they have several limitations, such as off-target toxicity, and drug-resistant fungi are now emerging. New antifungals are therefore needed. In this Review, I discuss the robust and dynamic antifungal pipeline, including results from preclinical academic efforts through to pharmaceutical industry products, and describe the targets, strategies, compounds and potential outcomes.
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Affiliation(s)
- John R Perfect
- Duke University Medical Center, 200 Trent Drive, Durham, North Carolina 27710, USA
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14
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The Celecoxib Derivative AR-12 Has Broad-Spectrum Antifungal Activity In Vitro and Improves the Activity of Fluconazole in a Murine Model of Cryptococcosis. Antimicrob Agents Chemother 2016; 60:7115-7127. [PMID: 27645246 DOI: 10.1128/aac.01061-16] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 09/04/2016] [Indexed: 12/24/2022] Open
Abstract
Only one new class of antifungal drugs has been introduced into clinical practice in the last 30 years, and thus the identification of small molecules with novel mechanisms of action is an important goal of current anti-infective research. Here, we describe the characterization of the spectrum of in vitro activity and in vivo activity of AR-12, a celecoxib derivative which has been tested in a phase I clinical trial as an anticancer agent. AR-12 inhibits fungal acetyl coenzyme A (acetyl-CoA) synthetase in vitro and is fungicidal at concentrations similar to those achieved in human plasma. AR-12 has a broad spectrum of activity, including activity against yeasts (e.g., Candida albicans, non-albicans Candida spp., Cryptococcus neoformans), molds (e.g., Fusarium, Mucor), and dimorphic fungi (Blastomyces, Histoplasma, and Coccidioides) with MICs of 2 to 4 μg/ml. AR-12 is also active against azole- and echinocandin-resistant Candida isolates, and subinhibitory AR-12 concentrations increase the susceptibility of fluconazole- and echinocandin-resistant Candida isolates. Finally, AR-12 also increases the activity of fluconazole in a murine model of cryptococcosis. Taken together, these data indicate that AR-12 represents a promising class of small molecules with broad-spectrum antifungal activity.
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15
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Pianalto KM, Alspaugh JA. New Horizons in Antifungal Therapy. J Fungi (Basel) 2016; 2:jof2040026. [PMID: 29376943 PMCID: PMC5715934 DOI: 10.3390/jof2040026] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 09/19/2016] [Accepted: 09/20/2016] [Indexed: 12/20/2022] Open
Abstract
Recent investigations have yielded both profound insights into the mechanisms required by pathogenic fungi for virulence within the human host, as well as novel potential targets for antifungal therapeutics. Some of these studies have resulted in the identification of novel compounds that act against these pathways and also demonstrate potent antifungal activity. However, considerable effort is required to move from pre-clinical compound testing to true clinical trials, a necessary step toward ultimately bringing new drugs to market. The rising incidence of invasive fungal infections mandates continued efforts to identify new strategies for antifungal therapy. Moreover, these life-threatening infections often occur in our most vulnerable patient populations. In addition to finding completely novel antifungal compounds, there is also a renewed effort to redirect existing drugs for use as antifungal agents. Several recent screens have identified potent antifungal activity in compounds previously indicated for other uses in humans. Together, the combined efforts of academic investigators and the pharmaceutical industry is resulting in exciting new possibilities for the treatment of invasive fungal infections.
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Affiliation(s)
- Kaila M Pianalto
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710, USA.
| | - J Andrew Alspaugh
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710, USA.
- Department of Medicine/Infectious Diseases, Duke University School of Medicine, Durham, NC 27710, USA.
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16
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Jeon BJ, Kim JD, Han JW, Kim BS. Antifungal activity of rimocidin and a new rimocidin derivative BU16 produced by Streptomyces mauvecolor BU16 and their effects on pepper anthracnose. J Appl Microbiol 2016; 120:1219-28. [PMID: 26808253 DOI: 10.1111/jam.13071] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 12/17/2015] [Accepted: 12/28/2015] [Indexed: 10/22/2022]
Abstract
AIMS The objective of this study was to explore antifungal metabolites targeting fungal cell envelope and to evaluate the control efficacy against anthracnose development in pepper plants. METHODS AND RESULTS A natural product library comprising 3000 microbial culture extracts was screened via an adenylate kinase (AK)-based cell lysis assay to detect antifungal metabolites targeting the cell envelope of plant-pathogenic fungi. The culture extract of Streptomyces mauvecolor strain BU16 displayed potent AK-releasing activity. Rimocidin and a new rimocidin derivative, BU16, were identified from the extract as active constituents. BU16 is a tetraene macrolide containing a six-membered hemiketal ring with an ethyl group side chain instead of the propyl group in rimocidin. Rimocidin and BU16 showed broad-spectrum antifungal activity against various plant-pathogenic fungi and demonstrated potent control efficacy against anthracnose development in pepper plants. CONCLUSIONS Antifungal metabolites produced by S. mauvecolor strain BU16 were identified to be rimocidin and BU16. The compounds displayed potent control efficacy against pepper anthracnose. SIGNIFICANCE AND IMPACT OF THE STUDY Rimocidin and BU16 would be active ingredients of disease control agents disrupting cell envelope of plant-pathogenic fungi. The structure and antifungal activity of rimocidin derivative BU16 is first described in this study.
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Affiliation(s)
- B J Jeon
- Laboratory of Plant Pharmacology, Department of Biosystems and Biotechnology, Korea University Graduate School, Seoul, Korea
| | - J D Kim
- Laboratory of Plant Pharmacology, Department of Biosystems and Biotechnology, Korea University Graduate School, Seoul, Korea
| | - J W Han
- Laboratory of Plant Pharmacology, Department of Biosystems and Biotechnology, Korea University Graduate School, Seoul, Korea
| | - B S Kim
- Laboratory of Plant Pharmacology, Department of Biosystems and Biotechnology, Korea University Graduate School, Seoul, Korea.,Division of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Korea
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17
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Hartland K, Pu J, Palmer M, Dandapani S, Moquist PN, Munoz B, DiDone L, Schreiber SL, Krysan DJ. High-Throughput Screen in Cryptococcus neoformans Identifies a Novel Molecular Scaffold That Inhibits Cell Wall Integrity Pathway Signaling. ACS Infect Dis 2016; 2:93-102. [PMID: 26807437 PMCID: PMC4709821 DOI: 10.1021/acsinfecdis.5b00111] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Indexed: 02/07/2023]
Abstract
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Cryptococcus neoformans is one of the most important
human fungal pathogens; however, no new therapies have been developed
in over 50 years. Fungicidal activity is crucially important for an
effective anticryptococal agent and, therefore, we screened 361,675
molecules against C. neoformans using an adenylate
kinase release assay that specifically detects fungicidal activity.
A set of secondary assays narrowed the set of hits to molecules that
interfere with fungal cell wall integrity and identified three benzothioureas
with low in vitro mammalian toxicity and good in vitro anticryptococcal
(minimum inhibitory concentration = 4 μg/mL). This scaffold
inhibits signaling through the cell wall integrity MAP kinase cascade.
Structure–activity studies indicate that the thiocarbonyl moiety
is crucial for activity. Genetic and biochemical data suggest that
benzothioureas inhibit signaling upstream of the kinase cascade. Thus,
the benzothioureas appear to be a promising new scaffold for further
exploration in the search for new anticryptococcal agents.
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Affiliation(s)
- Kate Hartland
- Center for the Science of Therapeutics, Broad Institute of Harvard and MIT, 7 Cambridge
Center, Cambridge, Massachusetts 02142, United States
| | - Jun Pu
- Center for the Science of Therapeutics, Broad Institute of Harvard and MIT, 7 Cambridge
Center, Cambridge, Massachusetts 02142, United States
| | - Michelle Palmer
- Center for the Science of Therapeutics, Broad Institute of Harvard and MIT, 7 Cambridge
Center, Cambridge, Massachusetts 02142, United States
| | - Sivaraman Dandapani
- Center for the Science of Therapeutics, Broad Institute of Harvard and MIT, 7 Cambridge
Center, Cambridge, Massachusetts 02142, United States
| | - Philip N. Moquist
- Center for the Science of Therapeutics, Broad Institute of Harvard and MIT, 7 Cambridge
Center, Cambridge, Massachusetts 02142, United States
| | - Benito Munoz
- Center for the Science of Therapeutics, Broad Institute of Harvard and MIT, 7 Cambridge
Center, Cambridge, Massachusetts 02142, United States
| | | | - Stuart L. Schreiber
- Center for the Science of Therapeutics, Broad Institute of Harvard and MIT, 7 Cambridge
Center, Cambridge, Massachusetts 02142, United States
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18
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Wong SSW, Samaranayake LP, Seneviratne CJ. In pursuit of the ideal antifungal agent for Candida infections: high-throughput screening of small molecules. Drug Discov Today 2014; 19:1721-1730. [PMID: 24952336 DOI: 10.1016/j.drudis.2014.06.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 05/23/2014] [Accepted: 06/12/2014] [Indexed: 01/22/2023]
Abstract
Candida infections have created a great burden on the public healthcare sector. The situation is worsened by recent epidemiological changes. Furthermore, the current arsenal of antifungal agents is limited and associated with undesirable drawbacks. Therefore, new antifungal agents that surpass the existing ones are urgently needed. High-throughput screening of small molecule libraries enables rapid hit identification and, possibly, increases hit rate. Moreover, the identified hits could be associated with unrecognized or multiple drug targets, which would provide novel insights into the biological processes of the pathogen. Hence, it is proposed that high-throughput screening of small molecules is particularly important in the pursuit of the ideal antifungal agents for Candida infections.
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Affiliation(s)
- Sarah S W Wong
- Faculty of Dentistry, University of Hong Kong, Hong Kong
| | | | - Chaminda J Seneviratne
- Faculty of Dentistry, University of Hong Kong, Hong Kong; Oral Sciences, Faculty of Dentistry, National University of Singapore, Singapore.
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19
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Cheah HL, Lim V, Sandai D. Inhibitors of the glyoxylate cycle enzyme ICL1 in Candida albicans for potential use as antifungal agents. PLoS One 2014; 9:e95951. [PMID: 24781056 PMCID: PMC4004578 DOI: 10.1371/journal.pone.0095951] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 04/02/2014] [Indexed: 01/09/2023] Open
Abstract
Candida albicans is an opportunistic pathogen that causes candidiasis in humans. In recent years, metabolic pathways in C. albicans have been explored as potential antifungal targets to treat candidiasis. The glyoxylate cycle, which enables C. albicans to survive in nutrient-limited host niches and its. Key enzymes (e.g., isocitrate lyase (ICL1), are particularly attractive antifungal targets for C. albicans. In this study, we used a new screening approach that better reflects the physiological environment that C. albicans cells experience during infection to identify potential inhibitors of ICL. Three compounds (caffeic acid (CAFF), rosmarinic acid (ROS), and apigenin (API)) were found to have antifungal activity against C. albicans when tested under glucose-depleted conditions. We further confirmed the inhibitory potential of these compounds against ICL using the ICL enzyme assay. Lastly, we assessed the bioavailability and toxicity of these compounds using Lipinski's rule-of-five and ADMET analysis.
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Affiliation(s)
- Hong-Leong Cheah
- Infectomic Cluster, Advanced Medical & Dental Institute, Universiti Sains Malaysia, Penang, Malaysia
| | - Vuanghao Lim
- Integrative Medicine Cluster, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Penang, Malaysia
| | - Doblin Sandai
- Infectomic Cluster, Advanced Medical & Dental Institute, Universiti Sains Malaysia, Penang, Malaysia
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20
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Reactive oxygen species-inducing antifungal agents and their activity against fungal biofilms. Future Med Chem 2014; 6:77-90. [DOI: 10.4155/fmc.13.189] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Invasive fungal infections are associated with very high mortality rates ranging from 20–90% for opportunistic fungal pathogens such as Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus. Fungal resistance to antimycotic treatment can be genotypic (due to resistant strains) as well as phenotypic (due to more resistant fungal lifestyles, such as biofilms). With regard to the latter, biofilms are considered to be critical in the development of invasive fungal infections. However, there are only very few antimycotics, such as miconazole (azoles), echinocandins and liposomal formulations of amphotericin B (polyenes), which are also effective against fungal biofilms. Interestingly, these antimycotics all induce reactive oxygen species (ROS) in fungal (biofilm) cells. This review provides an overview of the different classes of antimycotics and novel antifungal compounds that induce ROS in fungal planktonic and biofilm cells. Moreover, different strategies to further enhance the antibiofilm activity of such ROS-inducing antimycotics will be discussed.
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21
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Butts A, DiDone L, Koselny K, Baxter BK, Chabrier-Rosello Y, Wellington M, Krysan DJ. A repurposing approach identifies off-patent drugs with fungicidal cryptococcal activity, a common structural chemotype, and pharmacological properties relevant to the treatment of cryptococcosis. EUKARYOTIC CELL 2013; 12:278-87. [PMID: 23243064 PMCID: PMC3571299 DOI: 10.1128/ec.00314-12] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 12/10/2012] [Indexed: 11/20/2022]
Abstract
New, more accessible therapies for cryptococcosis represent an unmet clinical need of global importance. We took a repurposing approach to identify previously developed drugs with fungicidal activity toward Cryptococcus neoformans, using a high-throughput screening assay designed to detect drugs that directly kill fungi. From a set of 1,120 off-patent medications and bioactive molecules, we identified 31 drugs/molecules with fungicidal activity, including 15 drugs for which direct antifungal activity had not previously been reported. A significant portion of the drugs are orally bioavailable and cross the blood-brain barrier, features key to the development of a widely applicable anticryptococcal agent. Structural analysis of this set revealed a common chemotype consisting of a hydrophobic moiety linked to a basic amine, features that are common to drugs that cross the blood-brain barrier and access the phagolysosome, two important niches of C. neoformans. Consistent with their fungicidal activity, the set contains eight drugs that are either additive or synergistic in combination with fluconazole. Importantly, we identified two drugs, amiodarone and thioridazine, with activity against intraphagocytic C. neoformans. Finally, the set of drugs is also enriched for molecules that inhibit calmodulin, and we have confirmed that seven drugs directly bind C. neoformans calmodulin, providing a molecular target that may contribute to the mechanism of antifungal activity. Taken together, these studies provide a foundation for the optimization of the antifungal properties of a set of pharmacologically attractive scaffolds for the development of novel anticryptococcal therapies.
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Affiliation(s)
| | | | | | | | | | | | - Damian J. Krysan
- Pediatrics
- Microbiology/Immunology, University of Rochester, Rochester, New York, USA
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22
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Adenylate kinase release as a high-throughput-screening-compatible reporter of bacterial lysis for identification of antibacterial agents. Antimicrob Agents Chemother 2012; 57:26-36. [PMID: 23027196 DOI: 10.1128/aac.01640-12] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Adenylate kinase (AK) is a ubiquitous intracellular enzyme that is released into the extracellular space upon cell lysis. We have shown that AK release serves as a useful reporter of bactericidal agent activity and can be exploited for antimicrobial screening purposes. The AK assay exhibits improved sensitivity over that of growth-based assays and can detect agents that are active against bacteria in clinically relevant growth states that are difficult to screen using conventional approaches, such as small colony variants (SCV) and bacteria within established biofilms. The usefulness of the AK assay was validated by screening a library of off-patent drugs for agents that exhibit antimicrobial properties toward a variety of bacterial species, including Escherichia coli and all members of the "ESKAPE" pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species). The assay detected antibiotics within the library that were expected to be active against the organism screened. Moreover, 38 drugs with no previously reported antibacterial activity elicited AK release. Four of these were acquired, and all were verified to exhibit antimicrobial activity by standard susceptibility testing. Two of these molecules were further characterized. The antihistamine, terfenadine, was active against S. aureus planktonic, SCV population, and biofilm-associated cells. Tamoxifen, an estrogen receptor antagonist, was active toward E. faecium in vitro and also reduced E. faecium pathogenesis in a Galleria mellonella infection model. Our data demonstrate that the AK assay provides an attractive screening approach for identifying new antimicrobial agents. Further, terfenadine and tamoxifen may represent novel antimicrobial drug development scaffolds.
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23
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24
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Kim HY, Kim JD, Hong JS, Ham JH, Kim BS. Identification of antifungal niphimycin from Streptomyces sp. KP6107 by screening based on adenylate kinase assay. J Basic Microbiol 2012; 53:581-9. [PMID: 22915202 DOI: 10.1002/jobm.201200045] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2012] [Accepted: 04/09/2012] [Indexed: 11/08/2022]
Abstract
Microbial culture extracts are used for natural product screening to find antifungal lead compounds. A microbial culture extract library was constructed using 343 actinomycete isolates to examine the value of the adenylate kinase (AK) assay for screening to identify antifungal metabolites that disrupt cell integrity in plant pathogenic fungi. A culture extract of Streptomyces sp. strain KP6107 lysed cells of Fusarium oxysporum f.sp. lycopersici which resulted in high AK activity. The active ingredient N-1 was purified from the culture extract using various chromatographic procedures and identified to be the guanidyl-polyol macrolide antibiotic, niphimycin, which is a potent fungal cell membrane disruptor. Niphimycin showed broad-spectrum antifungal activity against Alternaria mali, Aspergillus oryzae, Colletotrichum coccodes, Colletotrichum gloeosporioides, Cercospora canescens, Cylindrocarpon destructans, F. oxysporum f.sp. cucumerinum, F. oxysporum f.sp. lycopersici, and Rhizoctonia solani at concentrations of 8-64 µg ml(-1). Anthracnose development in pepper plants was completely inhibited by treatment with 50 µg ml(-1) niphimycin, which was as effective as chlorothalonil. These results show that the AK assay is an efficient and selective tool in screening for cell membrane/wall disruptors of plant pathogenic fungi.
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Affiliation(s)
- Hye Yoon Kim
- Division of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
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25
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Snell SB, Foster TH, Haidaris CG. Miconazole induces fungistasis and increases killing of Candida albicans subjected to photodynamic therapy. Photochem Photobiol 2011; 88:596-603. [PMID: 22077904 DOI: 10.1111/j.1751-1097.2011.01039.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Cutaneous and mucocutaneous Candida infections are considered to be important targets for antimicrobial photodynamic therapy (PDT). Clinical application of antimicrobial PDT will require strategies that enhance microbial killing while minimizing damage to host tissue. Increasing the sensitivity of infectious agents to PDT will help achieve this goal. Our previous studies demonstrated that raising the level of oxidative stress in Candida by interfering with fungal respiration increased the efficiency of PDT. Therefore, we sought to identify compounds in clinical use that would augment the oxidative stress caused by PDT by contributing to reactive oxygen species (ROS) formation themselves. Based on the ability of the antifungal miconazole to induce ROS in Candida, we tested several azole antifungals for their ability to augment PDT in vitro. Although miconazole and ketoconazole both stimulated ROS production in Candida albicans, only miconazole enhanced the killing of C. albicans and induced prolonged fungistasis in organisms that survived PDT using the porphyrin TMP-1363 and the phenothiazine methylene blue as photosensitizers. The data suggest that miconazole could be used to increase the efficacy of PDT against C. albicans, and its mechanism of action is likely to be multifactorial.
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Affiliation(s)
- Sara B Snell
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, USA
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26
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DiDone L, Oga D, Krysan DJ. A novel assay of biofilm antifungal activity reveals that amphotericin B and caspofungin lyse Candida albicans cells in biofilms. Yeast 2011; 28:561-8. [DOI: 10.1002/yea.1860] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Accepted: 05/07/2011] [Indexed: 11/11/2022] Open
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27
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Kock JLF, Swart CW, Pohl CH. The anti-mitochondrial antifungal assay for the discovery and development of new drugs. Expert Opin Drug Discov 2011; 6:671-81. [PMID: 22646155 DOI: 10.1517/17460441.2011.575358] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
INTRODUCTION New targets and drugs are constantly searched for to effectively combat fungal infections and diseases such as cancer. Mitochondria, as the main powerhouses of eukaryotic cells, must be regarded as important targets for the development of new therapies. This has lead to the development of a fungal assay that shows potential in the selection of new antifungal and anticancer drugs as well as the identification of compounds that are toxic to human mitochondria. AREAS COVERED In this review the authors discuss the development of a potential method of drug discovery that targets mitochondrial function. The authors cover the application of new nanotechnology as well as fungal systematic research where the link between fungal fruiting structures, cell growth, increased mitochondrial activity and susceptibility to a variety of anti-mitochondrial drugs is assessed. EXPERT OPINION This assay shows potential to select anti-mitochondrial drugs as a first screen. This should be followed up by more specific in vitro and in vivo tests to pinpoint the type of anti-mitochondrial activity exerted by these drugs, if any. This is because the possibility exists that compounds regarded as anti-mitochondrial may not inhibit mitochondrial function but other fruiting structure developmental stages and therefore yield false positives. To enhance our knowledge on how these drugs act at the structural level, the authors recommend Nano Scanning Auger Microscopy as the tool of choice.
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Affiliation(s)
- J Lodewyk F Kock
- University of the Free State, Department of Microbial , Biochemical and Food Biotechnology, Bloemfontein , South Africa +27514012249 ; +27514019376 ;
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28
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DiDone L, Scrimale T, Baxter BK, Krysan DJ. A high-throughput assay of yeast cell lysis for drug discovery and genetic analysis. Nat Protoc 2010; 5:1107-14. [PMID: 20539286 DOI: 10.1038/nprot.2010.47] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The identification of new antifungal molecules is an important goal of current anti-infective research. To achieve this goal, alternatives to traditional growth inhibition-based screening have been developed in recent years. In this study, we describe an assay to detect molecules that disrupt yeast cell integrity by using the release of adenylate kinase (AK) into culture medium as a reporter of yeast cell lysis. The protocol is applicable to 96- and 384-well microtiter plate formats; uses a commercially available luminescence assay kit to detect AK activity; is more sensitive than traditional growth-based assays; and is specific for fungicidal compounds. In the high-throughput setting, the procedure provides excellent Z' scores (0.75-0.9), making it a highly robust assay. The AK assay is performed in a single microtiter plate using an 'add and read' procedure that can be completed in a single work day.
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Affiliation(s)
- Louis DiDone
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
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29
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Dolan K, Montgomery S, Buchheit B, Didone L, Wellington M, Krysan DJ. Antifungal activity of tamoxifen: in vitro and in vivo activities and mechanistic characterization. Antimicrob Agents Chemother 2009; 53:3337-46. [PMID: 19487443 PMCID: PMC2715577 DOI: 10.1128/aac.01564-08] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Revised: 01/28/2009] [Accepted: 05/25/2009] [Indexed: 11/20/2022] Open
Abstract
Tamoxifen (TAM), an estrogen receptor antagonist used primarily to treat breast cancer, has well-recognized antifungal properties, but the activity of TAM has not been fully characterized using standardized (i.e., CLSI) in vitro susceptibility testing, nor has it been demonstrated in an in vivo model of fungal infection. In addition, its mechanism of action remains to be clearly defined at the molecular level. Here, we report that TAM displays in vitro activity (MIC, 8 to 64 microg/ml) against pathogenic yeasts (Candida albicans, other Candida spp., and Cryptococcus neoformans). In vivo, 200 mg/kg of body weight per day TAM reduced kidney fungal burden (-1.5 log(10) CFU per g tissue; P = 0.008) in a murine model of disseminated candidiasis. TAM is a known inhibitor of mammalian calmodulin, and TAM-treated yeast show phenotypes consistent with decreased calmodulin function, including lysis, decreased new bud formation, disrupted actin polarization, and decreased germ tube formation. The overexpression of calmodulin suppresses TAM toxicity, hypofunctional calmodulin mutants are hypersensitive to TAM, and TAM interferes with the interaction between Myo2p and calmodulin, suggesting that TAM targets calmodulin as part of its mechanism of action. Taken together, these experiments indicate that the further study of compounds related to TAM as antifungal agents is warranted.
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Affiliation(s)
- Kristy Dolan
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
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30
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Role of the cell wall integrity and filamentous growth mitogen-activated protein kinase pathways in cell wall remodeling during filamentous growth. EUKARYOTIC CELL 2009; 8:1118-33. [PMID: 19502582 DOI: 10.1128/ec.00006-09] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Many fungal species including pathogens exhibit filamentous growth (FG) as a means of foraging for nutrients. Genetic screens were performed to identify genes required for FG in the budding yeast Saccharomyces cerevisiae. Genes encoding proteins with established functions in transcriptional activation (MCM1, MATalpha2, PHD1, MSN2, SIR4, and HMS2), cell wall integrity (MPT5, WSC2, and MID2), and cell polarity (BUD5) were identified as potential regulators of FG. The transcription factors MCM1 and MATalpha2 induced invasive growth by promoting diploid-specific bipolar budding in haploid cells. Components of the cell wall integrity pathway including the cell surface proteins Slg1p/Wsc1p, Wsc2p, Mid2p, and the mitogen-activated protein kinase (MAPK) Slt2p/Mpk1p contributed to multiple aspects of the FG response including cell elongation, cell-cell adherence, and agar invasion. Mid2p and Wsc2p stimulated the FG MAPK pathway through the signaling mucin Msb2p and components of the MAPK cascade. The FG pathway contributed to cell wall integrity in parallel with the cell wall integrity pathway and in opposition with the high osmolarity glycerol response pathway. Mass spectrometry approaches identified components of the filamentous cell wall including the mucin-like proteins Msb2p, Flo11p, and subtelomeric (silenced) mucin Flo10p. Secretion of Msb2p, which occurs as part of the maturation of the protein, was inhibited by the ss-1,3-glucan layer of the cell wall, which highlights a new regulatory aspect to cell wall remodeling in this organism. Disruption of ss-1,3-glucan linkages induced mucin shedding and resulted in defects in cell-cell adhesion and invasion of cells into the agar matrix.
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31
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Current awareness on yeast. Yeast 2009. [DOI: 10.1002/yea.1618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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