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Ross RL, Santiago-Tirado FH. Advanced genetic techniques in fungal pathogen research. mSphere 2024; 9:e0064323. [PMID: 38470131 PMCID: PMC11036804 DOI: 10.1128/msphere.00643-23] [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] [Indexed: 03/13/2024] Open
Abstract
Although fungi have been important model organisms for solving genetic, molecular, and ecological problems, recently, they are also becoming an important source of infectious disease. Despite their high medical burden, fungal pathogens are understudied, and relative to other pathogenic microbes, less is known about how their gene functions contribute to disease. This is due, in part, to a lack of powerful genetic tools to study these organisms. In turn, this has resulted in inappropriate treatments and diagnostics and poor disease management. There are a variety of reasons genetic studies were challenging in pathogenic fungi, but in recent years, most of them have been overcome or advances have been made to circumvent these barriers. In this minireview, we highlight how recent advances in genetic studies in fungal pathogens have resulted in the discovery of important biology and potential new antifungals and have created the tools to comprehensively study these important pathogens.
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Affiliation(s)
- Robbi L. Ross
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Felipe H. Santiago-Tirado
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, USA
- Warren Center for Drug Discovery, University of Notre Dame, Notre Dame, Indiana, USA
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2
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Iyer KR, Li SC, Revie NM, Lou JW, Duncan D, Fallah S, Sanchez H, Skulska I, Ušaj MM, Safizadeh H, Larsen B, Wong C, Aman A, Kiyota T, Yoshimura M, Kimura H, Hirano H, Yoshida M, Osada H, Gingras AC, Andes DR, Shapiro RS, Robbins N, Mazhab-Jafari MT, Whitesell L, Yashiroda Y, Boone C, Cowen LE. Identification of triazenyl indoles as inhibitors of fungal fatty acid biosynthesis with broad-spectrum activity. Cell Chem Biol 2023; 30:795-810.e8. [PMID: 37369212 PMCID: PMC11016341 DOI: 10.1016/j.chembiol.2023.06.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 04/17/2023] [Accepted: 06/01/2023] [Indexed: 06/29/2023]
Abstract
Rising drug resistance among pathogenic fungi, paired with a limited antifungal arsenal, poses an increasing threat to human health. To identify antifungal compounds, we screened the RIKEN natural product depository against representative isolates of four major human fungal pathogens. This screen identified NPD6433, a triazenyl indole with broad-spectrum activity against all screening strains, as well as the filamentous mold Aspergillus fumigatus. Mechanistic studies indicated that NPD6433 targets the enoyl reductase domain of fatty acid synthase 1 (Fas1), covalently inhibiting its flavin mononucleotide-dependent NADPH-oxidation activity and arresting essential fatty acid biosynthesis. Robust Fas1 inhibition kills Candida albicans, while sublethal inhibition impairs diverse virulence traits. At well-tolerated exposures, NPD6433 extended the lifespan of nematodes infected with azole-resistant C. albicans. Overall, identification of NPD6433 provides a tool with which to explore lipid homeostasis as a therapeutic target in pathogenic fungi and reveals a mechanism by which Fas1 function can be inhibited.
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Affiliation(s)
- Kali R Iyer
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Sheena C Li
- Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, ON, Canada; RIKEN Center for Sustainable Resource Science, Wako, Japan
| | - Nicole M Revie
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Jennifer W Lou
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Dustin Duncan
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Sara Fallah
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Hiram Sanchez
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI, USA
| | - Iwona Skulska
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Mojca Mattiazzi Ušaj
- Department of Chemistry and Biology, Toronto Metropolitan University, Toronto, ON, Canada
| | - Hamid Safizadeh
- Department of Computer Science and Engineering and Department of Electrical and Computer Engineering, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| | - Brett Larsen
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada; Lunenfeld-Tanenbaum Research Institute, Sinai Health, Toronto, ON, Canada
| | - Cassandra Wong
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada; Lunenfeld-Tanenbaum Research Institute, Sinai Health, Toronto, ON, Canada
| | - Ahmed Aman
- Drug Discovery Program, Ontario Institute for Cancer Research, Toronto, ON, Canada; Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada
| | - Taira Kiyota
- Drug Discovery Program, Ontario Institute for Cancer Research, Toronto, ON, Canada
| | - Mami Yoshimura
- RIKEN Center for Sustainable Resource Science, Wako, Japan
| | - Hiromi Kimura
- RIKEN Center for Sustainable Resource Science, Wako, Japan
| | | | - Minoru Yoshida
- RIKEN Center for Sustainable Resource Science, Wako, Japan
| | - Hiroyuki Osada
- RIKEN Center for Sustainable Resource Science, Wako, Japan
| | - Anne-Claude Gingras
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada; Lunenfeld-Tanenbaum Research Institute, Sinai Health, Toronto, ON, Canada
| | - David R Andes
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI, USA
| | - Rebecca S Shapiro
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Nicole Robbins
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Mohammad T Mazhab-Jafari
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; Princess Margaret Cancer Center, University Health Network, Toronto, ON, Canada
| | - Luke Whitesell
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Yoko Yashiroda
- RIKEN Center for Sustainable Resource Science, Wako, Japan.
| | - Charles Boone
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada; Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, ON, Canada; RIKEN Center for Sustainable Resource Science, Wako, Japan.
| | - Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.
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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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Hoy MJ, Heitman J. Drug Target Elucidation Through Isolation and Analysis of Drug-Resistant Mutants in Cryptococcus neoformans. Methods Mol Biol 2023; 2658:127-143. [PMID: 37024699 PMCID: PMC10602406 DOI: 10.1007/978-1-0716-3155-3_9] [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: 04/08/2023]
Abstract
Drug target identification is an essential component to antifungal drug development. Many methods, including large chemical library screening, natural product screening, and drug repurposing efforts, can identify compounds with favorable in vitro antifungal activity. However, these approaches will often identify compounds with no known mechanism of action. Herein, we describe a method utilizing the human fungal pathogen Cryptococcus neoformans to identify antifungal drug targets through the isolation of spontaneous resistant mutants, antifungal testing, whole-genome sequencing, and variant analysis.
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Affiliation(s)
- Michael J Hoy
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA.
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Andriani GM, Spoladori LFDA, Fabris M, Camargo PG, Pereira PML, Santos JP, Bartolomeu-Gonçalves G, Alonso L, Lancheros CAC, Alonso A, Nakamura CV, Macedo F, Pinge-Filho P, Yamauchi LM, Bispo MDLF, Tavares ER, Yamada-Ogatta SF. Synergistic antifungal interaction of N-(butylcarbamothioyl) benzamide and amphotericin B against Cryptococcus neoformans. Front Microbiol 2023; 14:1040671. [PMID: 36960287 PMCID: PMC10028264 DOI: 10.3389/fmicb.2023.1040671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 02/20/2023] [Indexed: 03/09/2023] Open
Abstract
Introduction Cryptococcus neoformans is one of the leading causes of invasive fungal infections worldwide. Cryptococcal meningoencephalitis is the main challenge of antifungal therapy due to high morbidity and mortality rates, especially in low- and middle-income countries. This can be partly attributed to the lack of specific diagnosis difficulty accessing treatment, antifungal resistance and antifungal toxicity. Methods In the present study, the effect of the synthetic thiourea derivative N-(butylcarbamothioyl) benzamide (BTU-01), alone and combined with amphotericin B (AmB), was evaluated in planktonic and sessile (biofilm) cells of C. neoformans. Results BTU-01 alone exhibited a fungistatic activity with minimal inhibitory concentrations (MICs) ranging from 31.25 to 62.5 μg/mL for planktonic cells; and sessile MICs ranging from 125.0 to 1000.0 μg/mL. BTU-01 caused a concentration-dependent inhibitory activity on cryptococcal urease and did not interfere with plasma membrane fluidity. Molecular docking was performed on Canavalia ensiformis urease, and BTU-01 showed relevant interactions with the enzyme. The combination of BTU-01 and AmB exhibited synergistic fungicidal activity against planktonic and sessile cells of C. neoformans. Microscopic analysis of C. neoformans treated with BTU-01, alone or combined with AmB, revealed a reduction in cell and capsule sizes, changes in the morphology of planktonic cells; a significant decrease in the number of cells within the biofilm; and absence of exopolymeric matrix surrounding the sessile cells. Neither hemolytic activity nor cytotoxicity to mammalian cells was detected for BTU-01, alone or combined with AmB, at concentrations that exhibited antifungal activity. BTU-01 also displayed drug-likeness properties. Conclusion These results indicate the potential of BTU-01, for the development of new strategies for controlling C. neoformans infections.
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Affiliation(s)
- Gabriella Maria Andriani
- Programa de Pós-graduação em Microbiologia, Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
- Laboratório de Biologia Molecular de Microrganismos, Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Lais Fernanda de Almeida Spoladori
- Programa de Pós-graduação em Microbiologia, Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
- Laboratório de Biologia Molecular de Microrganismos, Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Marciéli Fabris
- Laboratório de Síntese de Moléculas Medicinais, Departamento de Química, Centro de Ciências Exatas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Priscila Goes Camargo
- Laboratório de Síntese de Moléculas Medicinais, Departamento de Química, Centro de Ciências Exatas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Patrícia Morais Lopes Pereira
- Programa de Pós-graduação em Microbiologia, Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Jussevania Pereira Santos
- Laboratório de Biologia Molecular de Microrganismos, Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Guilherme Bartolomeu-Gonçalves
- Laboratório de Biologia Molecular de Microrganismos, Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
- Programa de Pós-graduação em Fisiopatologia Clínica e Laboratorial, Departamento de Patología, Análises Clínicas e Toxicológicas, Centro de Ciências da Saúde, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Lais Alonso
- Instituto de Física, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | - Cesar Armando Contreras Lancheros
- Laboratório de Inovação Tecnológica no Desenvolvimento de Fármacos e Cosméticos, Departamento de Ciências Básicas da Saúde, Centro de Ciências da Saúde, Universidade Estadual de Maringá, Maringá, Paraná, Brazil
| | - Antonio Alonso
- Instituto de Física, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | - Celso Vataru Nakamura
- Programa de Pós-graduação em Microbiologia, Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
- Laboratório de Inovação Tecnológica no Desenvolvimento de Fármacos e Cosméticos, Departamento de Ciências Básicas da Saúde, Centro de Ciências da Saúde, Universidade Estadual de Maringá, Maringá, Paraná, Brazil
| | - Fernando Macedo
- Laboratório de Síntese de Moléculas Medicinais, Departamento de Química, Centro de Ciências Exatas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Phileno Pinge-Filho
- Programa de Pós-graduação em Microbiologia, Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
- Laboratório de Imunopatologia Experimental, Departamento de Ciências Patológicas, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Lucy Megumi Yamauchi
- Programa de Pós-graduação em Microbiologia, Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
- Laboratório de Biologia Molecular de Microrganismos, Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Marcelle de Lima Ferreira Bispo
- Laboratório de Síntese de Moléculas Medicinais, Departamento de Química, Centro de Ciências Exatas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Eliandro Reis Tavares
- Programa de Pós-graduação em Microbiologia, Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
- Laboratório de Biologia Molecular de Microrganismos, Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Sueli Fumie Yamada-Ogatta
- Programa de Pós-graduação em Microbiologia, Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
- Laboratório de Biologia Molecular de Microrganismos, Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
- Programa de Pós-graduação em Fisiopatologia Clínica e Laboratorial, Departamento de Patología, Análises Clínicas e Toxicológicas, Centro de Ciências da Saúde, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
- *Correspondence: Sueli Fumie Yamada-Ogatta,
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de Oliveira HC, Castelli RF, Reis FCG, Samby K, Nosanchuk JD, Alves LR, Rodrigues ML. Screening of the Pandemic Response Box Reveals an Association between Antifungal Effects of MMV1593537 and the Cell Wall of Cryptococcus neoformans, Cryptococcus deuterogattii, and Candida auris. Microbiol Spectr 2022; 10:e0060122. [PMID: 35471056 PMCID: PMC9241760 DOI: 10.1128/spectrum.00601-22] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 04/11/2022] [Indexed: 11/20/2022] Open
Abstract
There is an urgent unmet need for novel antifungals. In this study, we searched for novel antifungal activities in the Pandemic Response Box, a collection of 400 structurally diverse compounds in various phases of drug discovery. We identified five molecules which could control the growth of Cryptococcus neoformans, Cryptococcus deuterogattii, and the emerging global threat Candida auris. After eliminating compounds which demonstrated paradoxical antifungal effects or toxicity to mammalian macrophages, we selected compound MMV1593537 as a nontoxic, fungicidal molecule for further characterization of antifungal activity. Scanning electron microscopy revealed that MMV1593537 affected cellular division in all three pathogens. In Cryptococcus, MMV1593537 caused a reduction in capsular dimensions. Treatment with MMV1593537 resulted in increased detection of cell wall chitooligomers in these three species. Since chitooligomers are products of the enzymatic hydrolysis of chitin, we investigated whether surface chitinase activity was altered in response to MMV1593537 exposure. We observed peaks of enzyme activity in C. neoformans and C. deuterogattii in response to MMV1593537. We did not detect any surface chitinase activity in C. auris. Our results suggest that MMV1593537 is a promising, nontoxic fungicide whose mechanism of action, at least in Cryptococcus spp, requires chitinase-mediated hydrolysis of chitin. IMPORTANCE The development of novel antifungals is a matter of urgency. In this study, we evaluated antifungal activities in a collection of 400 molecules, using highly lethal fungal pathogens as targets. One of these molecules, namely, MMV1593537, was not toxic to host cells and controlled the growth of isolates of Cryptococcus neoformans, C. deuterogattii, C. gattii, Candida auris, C. albicans, C. parapsilosis, and C. krusei. We tested the mechanisms of antifungal action of MMV1593537 in the Cryptococcus and C. auris models and concluded that the compound affects the cell wall, a structure which is essential for fungal life. At least in Cryptococcus, this effect involved chitinase, an enzyme which is required for remodeling the cell wall. Our results suggest that MMV1593537 is a candidate for future antifungal development.
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Affiliation(s)
| | - Rafael F. Castelli
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (Fiocruz), Curitiba, Brazil
- Programa de Pós-Graduação em Biologia Parasitária, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil
| | - Flavia C. G. Reis
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (Fiocruz), Curitiba, Brazil
- Centro de Desenvolvimento Tecnológico em Saúde (CDTS), Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | | | - Joshua D. Nosanchuk
- Department of Microbiology and Immunology and Division of Infectious Diseases, Albert Einstein College of Medicine of Yeshiva University, New York, New York, USA
| | - Lysangela R. Alves
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (Fiocruz), Curitiba, Brazil
| | - Marcio L. Rodrigues
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (Fiocruz), Curitiba, Brazil
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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Cell Wall Integrity Pathway Involved in Morphogenesis, Virulence and Antifungal Susceptibility in Cryptococcus neoformans. J Fungi (Basel) 2021; 7:jof7100831. [PMID: 34682253 PMCID: PMC8540506 DOI: 10.3390/jof7100831] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/28/2021] [Accepted: 09/30/2021] [Indexed: 11/17/2022] Open
Abstract
Due to its location, the fungal cell wall is the compartment that allows the interaction with the environment and/or the host, playing an important role during infection as well as in different biological functions such as cell morphology, cell permeability and protection against stress. All these processes involve the activation of signaling pathways within the cell. The cell wall integrity (CWI) pathway is the main route responsible for maintaining the functionality and proper structure of the cell wall. This pathway is highly conserved in the fungal kingdom and has been extensively characterized in Saccharomyces cerevisiae. However, there are still many unknown aspects of this pathway in the pathogenic fungi, such as Cryptococcus neoformans. This yeast is of particular interest because it is found in the environment, but can also behave as pathogen in multiple organisms, including vertebrates and invertebrates, so it has to adapt to multiple factors to survive in multiple niches. In this review, we summarize the components of the CWI pathway in C. neoformans as well as its involvement in different aspects such as virulence factors, morphological changes, and its role as target for antifungal therapies among others.
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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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Donlin MJ, Lane TR, Riabova O, Lepioshkin A, Xu E, Lin J, Makarov V, Ekins S. Discovery of 5-Nitro-6-thiocyanatopyrimidines as Inhibitors of Cryptococcus neoformans and Cryptococcus gattii. ACS Med Chem Lett 2021; 12:774-781. [PMID: 34055225 DOI: 10.1021/acsmedchemlett.1c00038] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 03/31/2021] [Indexed: 12/27/2022] Open
Abstract
Opportunistic infections from pathogenic fungi present a major challenge to healthcare because of a very limited arsenal of antifungal drugs, an increasing population of immunosuppressed patients, and increased prevalence of resistant clinical strains due to overuse of the few available antifungals. Cryptococcal meningitis is a life-threatening opportunistic fungal infection caused by one of two species in the Cryptococcus genus, Cryptococcus neoformans and Cryptococcus gattii. Eighty percent of cryptococcosis diseases are caused by C. neoformans that is endemic in the environment. The standard of care is limited to old antifungals, and under a high standard of care, mortality remains between 10 and 30%. We have identified a series of 5-nitro-6-thiocyanatopyrimidine antifungal drug candidates using in vitro and computational machine learning approaches. These compounds can inhibit C. neoformans growth at submicromolar levels, are effective against fluconazole-resistant C. neoformans and a clinical strain of C. gattii, and are not antagonistic with currently approved antifungals.
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Affiliation(s)
- Maureen J. Donlin
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, United States
- Institute for Drug and Biotherapeutic Development, Saint Louis University, St. Louis, Missouri 63103, United States
| | - Thomas R. Lane
- Collaborations Pharmaceuticals, Inc., Raleigh, North Carolina 27606, United States
| | - Olga Riabova
- Department of Biology, Saint Louis University, St. Louis, Missouri 63103, United States
| | - Alexander Lepioshkin
- Department of Biology, Saint Louis University, St. Louis, Missouri 63103, United States
| | - Evan Xu
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, United States
| | - Jeffrey Lin
- Department of Biology, Saint Louis University, St. Louis, Missouri 63103, United States
| | - Vadim Makarov
- Research Center of Biotechnology RAS, 119071 Moscow, Russia
| | - Sean Ekins
- Collaborations Pharmaceuticals, Inc., Raleigh, North Carolina 27606, United States
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Granato MQ, Mello TP, Nascimento RS, Pereira MD, Rosa TLSA, Pessolani MCV, McCann M, Devereux M, Branquinha MH, Santos ALS, Kneipp LF. Silver(I) and Copper(II) Complexes of 1,10-Phenanthroline-5,6-Dione Against Phialophora verrucosa: A Focus on the Interaction With Human Macrophages and Galleria mellonella Larvae. Front Microbiol 2021; 12:641258. [PMID: 34025603 PMCID: PMC8138666 DOI: 10.3389/fmicb.2021.641258] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 03/31/2021] [Indexed: 12/12/2022] Open
Abstract
Phialophora verrucosa is a dematiaceous fungus that causes mainly chromoblastomycosis, but also disseminated infections such as phaeohyphomycosis and mycetoma. These diseases are extremely hard to treat and often refractory to current antifungal therapies. In this work, we have evaluated the effect of 1,10-phenanthroline-5,6-dione (phendione) and its metal-based complexes, [Ag (phendione)2]ClO4 and [Cu(phendione)3](ClO4)2.4H2O, against P. verrucosa, focusing on (i) conidial viability when combined with amphotericin B (AmB); (ii) biofilm formation and disarticulation events; (iii) in vitro interaction with human macrophages; and (iv) in vivo infection of Galleria mellonella larvae. The combination of AmB with each of the test compounds promoted the additive inhibition of P. verrucosa growth, as judged by the checkerboard assay. During the biofilm formation process over polystyrene surface, sub-minimum inhibitory concentrations (MIC) of phendione and its silver(I) and copper(II) complexes were able to reduce biomass and extracellular matrix production. Moreover, a mature biofilm treated with high concentrations of the test compounds diminished biofilm viability in a concentration-dependent manner. Pre-treatment of conidial cells with the test compounds did not alter the percentage of infected THP-1 macrophages; however, [Ag(phendione)2]ClO4 caused a significant reduction in the number of intracellular fungal cells compared to the untreated system. In addition, the killing process was significantly enhanced by post-treatment of infected macrophages with the test compounds. P. verrucosa induced a typically cell density-dependent effect on G. mellonella larvae death after 7 days of infection. Interestingly, exposure to the silver(I) complex protected the larvae from P. verrucosa infection. Collectively, the results corroborate the promising therapeutic potential of phendione-based drugs against fungal infections, including those caused by P. verrucosa.
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Affiliation(s)
- Marcela Q. Granato
- Laboratório de Taxonomia, Bioquímica e Bioprospecção de Fungos (LTBBF), Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Thaís P. Mello
- Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes (LEAMER), Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Renata S. Nascimento
- Laboratório de Citotoxicidade e Genotoxicidade (LaCiGen), Instituto de Química, UFRJ, Rio de Janeiro, Brazil
| | - Marcos D. Pereira
- Laboratório de Citotoxicidade e Genotoxicidade (LaCiGen), Instituto de Química, UFRJ, Rio de Janeiro, Brazil
| | | | | | - Malachy McCann
- Department of Chemistry, Maynooth University, National University of Ireland, Maynooth, Ireland
| | - Michael Devereux
- Center for Biomimetic and Therapeutic Research, Focas Research Institute, Technological University Dublin, Dublin, Ireland
| | - Marta H. Branquinha
- Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes (LEAMER), Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - André L. S. Santos
- Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes (LEAMER), Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
- Laboratório de Citotoxicidade e Genotoxicidade (LaCiGen), Instituto de Química, UFRJ, Rio de Janeiro, Brazil
| | - Lucimar F. Kneipp
- Laboratório de Taxonomia, Bioquímica e Bioprospecção de Fungos (LTBBF), Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
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11
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Treatment strategies for cryptococcal infection: challenges, advances and future outlook. Nat Rev Microbiol 2021; 19:454-466. [PMID: 33558691 PMCID: PMC7868659 DOI: 10.1038/s41579-021-00511-0] [Citation(s) in RCA: 135] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2021] [Indexed: 01/31/2023]
Abstract
Cryptococcus spp., in particular Cryptococcus neoformans and Cryptococcus gattii, have an enormous impact on human health worldwide. The global burden of cryptococcal meningitis is almost a quarter of a million cases and 181,000 deaths annually, with mortality rates of 100% if infections remain untreated. Despite these alarming statistics, treatment options for cryptococcosis remain limited, with only three major classes of drugs approved for clinical use. Exacerbating the public health burden is the fact that the only new class of antifungal drugs developed in decades, the echinocandins, displays negligible antifungal activity against Cryptococcus spp., and the efficacy of the remaining therapeutics is hampered by host toxicity and pathogen resistance. Here, we describe the current arsenal of antifungal agents and the treatment strategies employed to manage cryptococcal disease. We further elaborate on the recent advances in our understanding of the intrinsic and adaptive resistance mechanisms that are utilized by Cryptococcus spp. to evade therapeutic treatments. Finally, we review potential therapeutic strategies, including combination therapy, the targeting of virulence traits, impairing stress response pathways and modulating host immunity, to effectively treat infections caused by Cryptococcus spp. Overall, understanding of the mechanisms that regulate anti-cryptococcal drug resistance, coupled with advances in genomics technologies and high-throughput screening methodologies, will catalyse innovation and accelerate antifungal drug discovery.
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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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13
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Beattie SR, Schnicker NJ, Murante T, Kettimuthu K, Williams NS, Gakhar L, Krysan DJ. Benzothiourea Derivatives Target the Secretory Pathway of the Human Fungal Pathogen Cryptococcus neoformans. ACS Infect Dis 2020; 6:529-539. [PMID: 32070095 DOI: 10.1021/acsinfecdis.9b00478] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Cryptococcus neoformans is one of the most important human fungal pathogens and causes life-threatening meningoencephalitis in immunocompromised patients. The current gold standard therapy for C. neoformans meningoencephalitis is based on medications that are over 50 years old and is not readily available in regions with high disease burden. Here, we report the mycologic, mechanistic, and pharmacologic characterization of a set of benzothioureas with highly selective fungicidal activity against C. neoformans. In addition, to direct antifungal activity, benzothioureas inhibit C. neoformans virulence traits. On the basis of a set of phenotypic, biochemical, and biophysical assays, the benzothioureas (BTUs) inhibit the late secretory pathway (post-Golgi), possibly through a direct interaction with Sav1, an orthologue of the Sec4-class small GTPase. Importantly, pharmacological characterization of the BTUs indicates it readily penetrates the blood-brain barrier. Together, our data support the further development of this scaffold as an antifungal agent with a novel mechanism of action against C. neoformans.
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Affiliation(s)
- Sarah R. Beattie
- Department of Pediatrics, Carver College of Medicine, University of Iowa, 25 South Grand Avenue, Iowa City, Iowa 52245, United States
| | - Nicholas J. Schnicker
- Protein and Crystallography Facility, Carver College of Medicine, University of Iowa, 51 Newton Road, Iowa City, Iowa 52245, United States
| | - Thomas Murante
- Department of Pediatrics, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642, United States
| | - Kavitha Kettimuthu
- Department of Biochemistry, University of Texas Southwestern, 5323 Harry Hines Boulevard, Dallas, Texas 75390, United States
| | - Noelle S. Williams
- Department of Biochemistry, University of Texas Southwestern, 5323 Harry Hines Boulevard, Dallas, Texas 75390, United States
| | - Lokesh Gakhar
- Protein and Crystallography Facility, Carver College of Medicine, University of Iowa, 51 Newton Road, Iowa City, Iowa 52245, United States
- Department of Biochemistry, Carver College of Medicine, University of Iowa, 51 Newton Road, Iowa City, Iowa 52245, United States
| | - Damian J. Krysan
- Department of Pediatrics, Carver College of Medicine, University of Iowa, 25 South Grand Avenue, Iowa City, Iowa 52245, United States
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, 25 South Grand Avenue, Iowa City, Iowa 52245, United States
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14
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Abstract
To survive under unpredictable conditions, all organisms must adapt to stressors by regulating adaptive cellular responses. Arrestin proteins are conserved regulators of adaptive cellular responses in eukaryotes. Studies that have been limited to mammals and model fungi have demonstrated that the disruption of arrestin-regulated pathways is detrimental for viability. The human fungal pathogen Cryptococcus neoformans causes more than 180,000 infection-related deaths annually, especially among immunocompromised patients. In addition to being genetically tractable, C. neoformans has a small arrestin family of four members, lending itself to a comprehensive characterization of its arrestin family. This study serves as a functional analysis of arrestins in a pathogen, particularly in the context of fungal fitness and virulence. We investigate the functions of one arrestin protein, Ali1, and define its novel contributions to cytokinesis. We additionally explore the virulence contributions of the C. neoformans arrestin family and find that they contribute to disease establishment and progression. Arrestins, a structurally specialized and functionally diverse group of proteins, are central regulators of adaptive cellular responses in eukaryotes. Previous studies on fungal arrestins have demonstrated their capacity to modulate diverse cellular processes through their adaptor functions, facilitating the localization and function of other proteins. However, the mechanisms by which arrestin-regulated processes are involved in fungal virulence remain unexplored. We have identified a small family of four arrestins, Ali1, Ali2, Ali3, and Ali4, in the human fungal pathogen Cryptococcus neoformans. Using complementary microscopy, proteomic, and reverse genetics techniques, we have defined a role for Ali1 as a novel contributor to cytokinesis, a fundamental cell cycle-associated process. We observed that Ali1 strongly interacts with proteins involved in lipid synthesis, and that ali1Δ mutant phenotypes are rescued by supplementation with lipid precursors that are used to build cellular membranes. From these data, we hypothesize that Ali1 contributes to cytokinesis by serving as an adaptor protein, facilitating the localization of enzymes that modify the plasma membrane during cell division, specifically the fatty acid synthases Fas1 and Fas2. Finally, we assessed the contributions of the C. neoformans arrestin family to virulence to better understand the mechanisms by which arrestin-regulated adaptive cellular responses influence fungal infection. We observed that the C. neoformans arrestin family contributes to virulence, and that the individual arrestin proteins likely fulfill distinct functions that are important for disease progression.
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Spicer SK, Subramani A, Aguila AL, Green RM, McClelland EE, Bicker KL. Toward a clinical antifungal peptoid: Investigations into the therapeutic potential of AEC5. Biopolymers 2019; 110:e23276. [PMID: 30938841 PMCID: PMC6660985 DOI: 10.1002/bip.23276] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 03/13/2019] [Accepted: 03/18/2019] [Indexed: 01/08/2023]
Abstract
Cryptococcus neoformans is a fungal pathogen that causes cryptococcal meningitis in immunocompromised individuals. Existing antifungal treatment plans have high mammalian toxicity and increasing drug resistance, demonstrating the dire need for new, nontoxic therapeutics. Antimicrobial peptoids are one alternative to combat this issue. Our lab has recently identified a tripeptoid, AEC5, with promising efficacy and selectivity against C. neoformans. Here, we report studies into the broad-spectrum efficacy, killing kinetics, mechanism of action, in vivo half-life, and subchronic toxicity of this compound. Most notably, these studies have demonstrated that AEC5 rapidly reduces fungal burden, killing all viable fungi within 3 hours. Additionally, AEC5 has an in vivo half-life of 20+ hours and no observable in vivo toxicity following 28 days of daily injections. This research represents an important step in the characterization of AEC5 as a practical treatment option against C. neoformans infections.
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Affiliation(s)
- Sabrina K. Spicer
- Middle Tennessee State University, Department of Chemistry, 1301 E. Main St., Murfreesboro, TN 37132
| | - Aarthi Subramani
- Middle Tennessee State University, Department of Biology, 1301 E. Main St., Murfreesboro, TN 37132
| | - Angelica L. Aguila
- Middle Tennessee State University, Department of Chemistry, 1301 E. Main St., Murfreesboro, TN 37132
| | - R. Madison Green
- Middle Tennessee State University, Department of Chemistry, 1301 E. Main St., Murfreesboro, TN 37132
| | - Erin E. McClelland
- Middle Tennessee State University, Department of Biology, 1301 E. Main St., Murfreesboro, TN 37132
| | - Kevin L. Bicker
- Middle Tennessee State University, Department of Chemistry, 1301 E. Main St., Murfreesboro, TN 37132
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16
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Troponoids Can Inhibit Growth of the Human Fungal Pathogen Cryptococcus neoformans. Antimicrob Agents Chemother 2017; 61:AAC.02574-16. [PMID: 28167553 DOI: 10.1128/aac.02574-16] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 02/01/2017] [Indexed: 12/18/2022] Open
Abstract
Cryptococcus neoformans is a pathogen that is common in immunosuppressed patients. It can be treated with amphotericin B and fluconazole, but the mortality rate remains 15 to 30%. Thus, novel and more effective anticryptococcal therapies are needed. The troponoids are based on natural products isolated from western red cedar, and have a broad range of antimicrobial activities. Extracts of western red cedar inhibit the growth of several fungal species, but neither western red cedar extracts nor troponoid derivatives have been tested against C. neoformans We screened 56 troponoids for their ability to inhibit C. neoformans growth and to assess whether they may be attractive candidates for development into anticryptococcal drugs. We determined MICs at which the compounds inhibited 80% of cryptococcal growth relative to vehicle-treated controls and identified 12 compounds with MICs ranging from 0.2 to 15 μM. We screened compounds with MICs of ≤20 μM for cytotoxicity in liver hepatoma cells. Fifty percent cytotoxicity values (CC50s) ranged from 4 to >100 μM. The therapeutic indexes (TI, CC50/MIC) for most of the troponoids were fairly low, with most being <8. However, two compounds had TI values that were >8, including a tropone with a TI of >300. These tropones are fungicidal and are not antagonistic when used in combination with fluconazole or amphotericin B. Inhibition by these two tropones remains unchanged under conditions favoring cryptococcal capsule formation. These data support the hypothesis that troponoids may be a productive scaffold for the development of novel anticryptococcal therapies.
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17
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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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19
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Ngo HX, Garneau-Tsodikova S, Green KD. A complex game of hide and seek: the search for new antifungals. MEDCHEMCOMM 2016; 7:1285-1306. [PMID: 27766140 PMCID: PMC5067021 DOI: 10.1039/c6md00222f] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Fungal infections directly affect millions of people each year. In addition to the invasive fungal infections of humans, the plants and animals that comprise our primary food source are also susceptible to diseases caused by these eukaryotic microbes. The need for antifungals, not only for our medical needs, but also for use in agriculture and livestock causes a high demand for novel antimycotics. Herein, we provide an overview of the most commonly used antifungals in medicine and agriculture. We also present a summary of the recent progress (from 2010-2016) in the discovery/development of new agents against fungal strains of medical/agricultural relevance, as well as information related to their biological activity, their mode(s) of action, and their mechanism(s) of resistance.
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Affiliation(s)
- Huy X. Ngo
- University of Kentucky, Department of Pharmaceutical Sciences, 789 South Limestone Street, Lexington, KY, USA. Fax: 859-257-7585; Tel: 859-218-1686
| | - Sylvie Garneau-Tsodikova
- University of Kentucky, Department of Pharmaceutical Sciences, 789 South Limestone Street, Lexington, KY, USA. Fax: 859-257-7585; Tel: 859-218-1686
| | - Keith D. Green
- University of Kentucky, Department of Pharmaceutical Sciences, 789 South Limestone Street, Lexington, KY, USA. Fax: 859-257-7585; Tel: 859-218-1686
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20
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Spitzer M, Robbins N, Wright GD. Combinatorial strategies for combating invasive fungal infections. Virulence 2016; 8:169-185. [PMID: 27268286 DOI: 10.1080/21505594.2016.1196300] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Invasive fungal infections are an important cause of human mortality and morbidity, particularly for immunocompromised populations. However, there remains a paucity of antifungal drug treatments available to combat these fungal pathogens. Further, antifungal compounds are plagued with problems such as host toxicity, fungistatic activity, and the emergence of drug resistance in pathogen populations. A promising therapeutic strategy to increase drug effectiveness and mitigate the emergence of drug resistance is through the use of combination drug therapy. In this review we describe the current arsenal of antifungals in medicine and elaborate on the benefits of combination therapy to expand our current antifungal drug repertoire. We examine those antifungal combinations that have shown potential against fungal pathogens and discuss strategies being employed to discover novel combination therapeutics, in particular combining antifungal agents with non-antifungal bioactive compounds. The findings summarized in this review highlight the promise of combinatorial strategies in combatting invasive mycoses.
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Affiliation(s)
- Michaela Spitzer
- a Michael G. DeGroote Institute for Infectious Disease Research and the Department of Biochemistry and Biomedical Sciences , McMaster University , Hamilton , ON , Canada
| | - Nicole Robbins
- a Michael G. DeGroote Institute for Infectious Disease Research and the Department of Biochemistry and Biomedical Sciences , McMaster University , Hamilton , ON , Canada
| | - Gerard D Wright
- a Michael G. DeGroote Institute for Infectious Disease Research and the Department of Biochemistry and Biomedical Sciences , McMaster University , Hamilton , ON , Canada
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