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Pomeroy J, Khalifa MM, Milanes JE, Palmentiero CM, Morris JC, Golden JE. Synthesis and Evaluation of Benzylamine Inhibitors of Neuropathogenic Naegleria fowleri "Brain-Eating" Amoeba. ACS Med Chem Lett 2024; 15:87-92. [PMID: 38229759 PMCID: PMC10789148 DOI: 10.1021/acsmedchemlett.3c00440] [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: 09/28/2023] [Revised: 12/21/2023] [Accepted: 12/26/2023] [Indexed: 01/18/2024] Open
Abstract
Current therapy for primary amoebic meningoencephalitis (PAM), a highly lethal brain infection in humans caused by Naegleria fowleri amoeba, is restricted to repurposed drugs with limited efficacy and success. Discovery of an antiamoebic benzylamine scaffold 2 precipitated a medicinal chemistry effort to improve potency, cytotoxicity profile, and drug-like properties. Thirty-four compounds were prepared, leading to compound 28 with significant gains in potency (EC50 = 0.92 μM), solubility, and microsomal stability and a demonstrated absence of cytotoxicity in SH-SY5Y human neuroblastoma cells (CC50 > 20 μM). The compounds demonstrated excellent blood-brain barrier permeability in an in vitro assay, thereby providing a new structural scaffold that inhibits N. fowleri viability and permits the investigation of therapeutic interventions in an understudied neglected disease.
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Affiliation(s)
- Julia
M. Pomeroy
- Department
of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United
States
| | - Muhammad M. Khalifa
- School
of Pharmacy, Division of Pharmaceutical Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Jillian E. Milanes
- Eukaryotic
Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina 29634, United States
| | - Caroline M. Palmentiero
- Eukaryotic
Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina 29634, United States
| | - James C. Morris
- Eukaryotic
Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina 29634, United States
| | - Jennifer E. Golden
- Department
of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United
States
- School
of Pharmacy, Division of Pharmaceutical Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
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2
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Sharma V, Madia VN, Tudino V, Nguyen JV, Debnath A, Messore A, Ialongo D, Patacchini E, Palenca I, Basili Franzin S, Seguella L, Esposito G, Petrucci R, Di Matteo P, Bortolami M, Saccoliti F, Di Santo R, Scipione L, Costi R, Podust LM. Miconazole-like Scaffold is a Promising Lead for Naegleria fowleri-Specific CYP51 Inhibitors. J Med Chem 2023; 66:17059-17073. [PMID: 38085955 PMCID: PMC10758121 DOI: 10.1021/acs.jmedchem.3c01898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/17/2023] [Accepted: 11/22/2023] [Indexed: 12/29/2023]
Abstract
Developing drugs for brain infection by Naegleria fowleri is an unmet medical need. We used a combination of cheminformatics, target-, and phenotypic-based drug discovery methods to identify inhibitors that target an essential N. fowleri enzyme, sterol 14-demethylase (NfCYP51). A total of 124 compounds preselected in silico were tested against N. fowleri. Nine primary hits with EC50 ≤ 10 μM were phenotypically identified. Cocrystallization with NfCYP51 focused attention on one primary hit, miconazole-like compound 2a. The S-enantiomer of 2a produced a 1.74 Å cocrystal structure. A set of analogues was then synthesized and evaluated to confirm the superiority of the S-configuration over the R-configuration and the advantage of an ether linkage over an ester linkage. The two compounds, S-8b and S-9b, had an improved EC50 and KD compared to 2a. Importantly, both were readily taken up into the brain. The brain-to-plasma distribution coefficient of S-9b was 1.02 ± 0.12, suggesting further evaluation as a lead for primary amoebic meningoencephalitis.
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Affiliation(s)
- Vandna Sharma
- Skaggs
School of Pharmacy and Pharmaceutical Sciences, Center for Discovery
and Innovation in Parasitic Diseases, University
of California San Diego, La Jolla, California 92093, United States
| | - Valentina Noemi Madia
- Dipartimento
di Chimica e Tecnologie del Farmaco, Istituto Pasteur-Fondazione Cenci
Bolognetti, “Sapienza” Università
di Roma, p.le Aldo Moro 5, Rome I-00185, Italy
| | - Valeria Tudino
- Dipartimento
di Biotecnologie, Università degli
Studi di Siena, Chimica e Farmacia via Aldo Moro 2, Siena 53100, Italy
| | - Jennifer V. Nguyen
- Skaggs
School of Pharmacy and Pharmaceutical Sciences, Center for Discovery
and Innovation in Parasitic Diseases, University
of California San Diego, La Jolla, California 92093, United States
| | - Anjan Debnath
- Skaggs
School of Pharmacy and Pharmaceutical Sciences, Center for Discovery
and Innovation in Parasitic Diseases, University
of California San Diego, La Jolla, California 92093, United States
| | - Antonella Messore
- Dipartimento
di Chimica e Tecnologie del Farmaco, Istituto Pasteur-Fondazione Cenci
Bolognetti, “Sapienza” Università
di Roma, p.le Aldo Moro 5, Rome I-00185, Italy
| | - Davide Ialongo
- Dipartimento
di Chimica e Tecnologie del Farmaco, Istituto Pasteur-Fondazione Cenci
Bolognetti, “Sapienza” Università
di Roma, p.le Aldo Moro 5, Rome I-00185, Italy
| | - Elisa Patacchini
- Dipartimento
di Chimica e Tecnologie del Farmaco, Istituto Pasteur-Fondazione Cenci
Bolognetti, “Sapienza” Università
di Roma, p.le Aldo Moro 5, Rome I-00185, Italy
| | - Irene Palenca
- Department
of Physiology and Pharmacology “V. Erspamer”, “Sapienza″ Università di Roma, p.le Aldo Moro 5, Rome I-00185, Italy
| | - Silvia Basili Franzin
- Department
of Physiology and Pharmacology “V. Erspamer”, “Sapienza″ Università di Roma, p.le Aldo Moro 5, Rome I-00185, Italy
| | - Luisa Seguella
- Department
of Physiology and Pharmacology “V. Erspamer”, “Sapienza″ Università di Roma, p.le Aldo Moro 5, Rome I-00185, Italy
| | - Giuseppe Esposito
- Department
of Physiology and Pharmacology “V. Erspamer”, “Sapienza″ Università di Roma, p.le Aldo Moro 5, Rome I-00185, Italy
| | - Rita Petrucci
- Dipartimento
di Scienze di Base e Applicate per l’Ingegneria, “Sapienza” Università di Roma, Via Castro Laurenziano 7, Rome 00161, Italy
| | - Paola Di Matteo
- Dipartimento
di Scienze di Base e Applicate per l’Ingegneria, “Sapienza” Università di Roma, Via Castro Laurenziano 7, Rome 00161, Italy
| | - Martina Bortolami
- Dipartimento
di Scienze di Base e Applicate per l’Ingegneria, “Sapienza” Università di Roma, Via Castro Laurenziano 7, Rome 00161, Italy
| | - Francesco Saccoliti
- D3 PharmaChemistry, Italian
Institute of Technology, Via Morego 30, Genova 16163, Italy
| | - Roberto Di Santo
- Dipartimento
di Chimica e Tecnologie del Farmaco, Istituto Pasteur-Fondazione Cenci
Bolognetti, “Sapienza” Università
di Roma, p.le Aldo Moro 5, Rome I-00185, Italy
| | - Luigi Scipione
- Dipartimento
di Chimica e Tecnologie del Farmaco, Istituto Pasteur-Fondazione Cenci
Bolognetti, “Sapienza” Università
di Roma, p.le Aldo Moro 5, Rome I-00185, Italy
| | - Roberta Costi
- Dipartimento
di Chimica e Tecnologie del Farmaco, Istituto Pasteur-Fondazione Cenci
Bolognetti, “Sapienza” Università
di Roma, p.le Aldo Moro 5, Rome I-00185, Italy
| | - Larissa M. Podust
- Skaggs
School of Pharmacy and Pharmaceutical Sciences, Center for Discovery
and Innovation in Parasitic Diseases, University
of California San Diego, La Jolla, California 92093, United States
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3
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Nadeem A, Malik IA, Afridi EK, Shariq F. Naegleria fowleri outbreak in Pakistan: unveiling the crisis and path to recovery. Front Public Health 2023; 11:1266400. [PMID: 37927850 PMCID: PMC10620794 DOI: 10.3389/fpubh.2023.1266400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 09/29/2023] [Indexed: 11/07/2023] Open
Abstract
The outbreak of Naegleria fowleri in Pakistan presents a significant public health concern due to its high fatality rate and limited treatment options. This review explores the impact of the outbreak on communities and the challenges faced in combating the disease. It evaluates available treatment options and highlights the need for early diagnosis and intervention. The study proposes recommendations to improve public health preparedness, including public awareness campaigns, enhanced healthcare infrastructure, and robust water surveillance systems. Collaboration between research institutions and public health organizations is emphasized to develop effective outbreak response strategies.
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Affiliation(s)
- Abdullah Nadeem
- Department of Medicine, Dow University of Health Sciences, Karachi, Pakistan
| | - Inshal Arshad Malik
- Department of Medicine, Jinnah Sindh Medical University, Karachi, Sindh, Pakistan
| | - Eesha Khan Afridi
- Department of Medicine, Jinnah Sindh Medical University, Karachi, Sindh, Pakistan
| | - Fariha Shariq
- Department of Medicine, Karachi Medical and Dental College, Karachi, Sindh, Pakistan
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4
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Russell AC, Bush P, Grigorean G, Kyle DE. Characterization of the extracellular vesicles, ultrastructural morphology, and intercellular interactions of multiple clinical isolates of the brain-eating amoeba, Naegleria fowleri. Front Microbiol 2023; 14:1264348. [PMID: 37808283 PMCID: PMC10558758 DOI: 10.3389/fmicb.2023.1264348] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 09/08/2023] [Indexed: 10/10/2023] Open
Abstract
Introduction As global temperatures rise to unprecedented historic levels, so too do the latitudes of habitable niches for the pathogenic free-living amoeba, Naegleria fowleri. This opportunistic parasite causes a rare, but >97% fatal, neurological infection called primary amoebic meningoencephalitis. Despite its lethality, this parasite remains one of the most neglected and understudied parasitic protozoans. Methods To better understand amoeboid intercellular communication, we elucidate the structure, proteome, and potential secretion mechanisms of amoeba-derived extracellular vesicles (EVs), which are membrane-bound communication apparatuses that relay messages and can be used as biomarkers for diagnostics in various diseases. Results and Discussion Herein we propose that N. fowleri secretes EVs in clusters from the plasma membrane, from multivesicular bodies, and via beading of thin filaments extruding from the membrane. Uptake assays demonstrate that EVs are taken up by other amoebae and mammalian cells, and we observed a real-time increase in metabolic activity for mammalian cells exposed to EVs from amoebae. Proteomic analysis revealed >2,000 proteins within the N. fowleri-secreted EVs, providing targets for the development of diagnostics or therapeutics. Our work expands the knowledge of intercellular interactions among these amoebae and subsequently deepens the understanding of the mechanistic basis of PAM.
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Affiliation(s)
- A. Cassiopeia Russell
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
- Department of Infectious Diseases, University of Georgia, Athens, GA, United States
| | - Peter Bush
- School of Dental Medicine, University at Buffalo, Buffalo, NY, United States
| | - Gabriela Grigorean
- Proteomics Core Facility, University of California, Davis, Davis, CA, United States
| | - Dennis E. Kyle
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
- Department of Infectious Diseases, University of Georgia, Athens, GA, United States
- Department of Cellular Biology, University of Georgia, Athens, GA, United States
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5
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Chao-Pellicer J, Arberas-Jiménez I, Delgado-Hernández S, Sifaoui I, Tejedor D, García-Tellado F, Piñero JE, Lorenzo-Morales J. Cyanomethyl Vinyl Ethers Against Naegleria fowleri. ACS Chem Neurosci 2023. [PMID: 37167960 DOI: 10.1021/acschemneuro.3c00110] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023] Open
Abstract
Naegleria fowleri is a pathogenic amoeba that causes a fulminant and rapidly progressive disease affecting the central nervous system called primary amoebic meningoencephalitis (PAM). Moreover, the disease is fatal in more than 97% of the reported cases, mostly affecting children and young people after practicing aquatic activities in nontreated fresh and warm water bodies contaminated with these amoebae. Currently, the treatment of primary amoebic meningoencephalitis is based on a combination of different antibiotics and antifungals, which are not entirely effective and lead to numerous side effects. In the recent years, research against PAM is focused on the search of novel, less toxic, and fully effective antiamoebic agents. Previous studies have reported the activity of cyano-substituted molecules in different protozoa. Therefore, the activity of 46 novel synthetic cyanomethyl vinyl ethers (QOET-51 to QOET-96) against two type strains of N. fowleri (ATCC 30808 and ATCC 30215) was determined. The data showed that QOET-51, QOET-59, QOET-64, QOET-67, QOET-72, QOET-77, and QOET-79 were the most active molecules. In fact, the selectivity index (CC50/IC50) was sixfold higher when compared to the activities of the drugs of reference. In addition, the mechanism of action of these compounds was studied, with the aim to demonstrate the induction of a programmed cell death process in N. fowleri.
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Affiliation(s)
- Javier Chao-Pellicer
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna, Avda. Astrofísico Fco. Sánchez, S/N, La Laguna 38203, Tenerife, Islas Canarias, Spain
- Departamento de Obstetricia y Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología, Universidad de La Laguna, Tenerife, Islas Canarias 38200, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid 28220, Spain
| | - Iñigo Arberas-Jiménez
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna, Avda. Astrofísico Fco. Sánchez, S/N, La Laguna 38203, Tenerife, Islas Canarias, Spain
- Departamento de Obstetricia y Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología, Universidad de La Laguna, Tenerife, Islas Canarias 38200, Spain
| | - Samuel Delgado-Hernández
- Instituto de Productos Naturales y Agrobiología, Consejo Superior de Investigaciones Científicas, Avda. Fco. Sánchez 3, La Laguna 38206, Tenerife, Islas Canarias, Spain
- Departamento de Química. Unidad Departamental de Química Analítica, Universidad de La Laguna (ULL), Tenerife 38206, Spain
| | - Ines Sifaoui
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna, Avda. Astrofísico Fco. Sánchez, S/N, La Laguna 38203, Tenerife, Islas Canarias, Spain
- Departamento de Obstetricia y Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología, Universidad de La Laguna, Tenerife, Islas Canarias 38200, Spain
| | - David Tejedor
- Instituto de Productos Naturales y Agrobiología, Consejo Superior de Investigaciones Científicas, Avda. Fco. Sánchez 3, La Laguna 38206, Tenerife, Islas Canarias, Spain
- Departamento de Química. Unidad Departamental de Química Analítica, Universidad de La Laguna (ULL), Tenerife 38206, Spain
| | - Fernando García-Tellado
- Instituto de Productos Naturales y Agrobiología, Consejo Superior de Investigaciones Científicas, Avda. Fco. Sánchez 3, La Laguna 38206, Tenerife, Islas Canarias, Spain
- Departamento de Química. Unidad Departamental de Química Analítica, Universidad de La Laguna (ULL), Tenerife 38206, Spain
| | - José E Piñero
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna, Avda. Astrofísico Fco. Sánchez, S/N, La Laguna 38203, Tenerife, Islas Canarias, Spain
- Departamento de Obstetricia y Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología, Universidad de La Laguna, Tenerife, Islas Canarias 38200, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid 28220, Spain
| | - Jacob Lorenzo-Morales
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna, Avda. Astrofísico Fco. Sánchez, S/N, La Laguna 38203, Tenerife, Islas Canarias, Spain
- Departamento de Obstetricia y Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología, Universidad de La Laguna, Tenerife, Islas Canarias 38200, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid 28220, Spain
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6
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Ferrins L, Buskes MJ, Kapteyn MM, Engels HN, Enos SE, Lu C, Klug DM, Singh B, Quotadamo A, Bachovchin K, Tear WF, Spaulding AE, Forbes KC, Bag S, Rivers M, LeBlanc C, Burchfield E, Armand JR, Diaz-Gonzalez R, Ceballos-Perez G, García-Hernández R, Pérez-Moreno G, Bosch-Navarrete C, Gómez-Liñán C, Ruiz-Pérez LM, Gamarro F, González-Pacanowska D, Navarro M, Mensa-Wilmot K, Pollastri MP, Kyle DE, Rice CA. Identification of novel anti-amoebic pharmacophores from kinase inhibitor chemotypes. Front Microbiol 2023; 14:1149145. [PMID: 37234530 PMCID: PMC10206040 DOI: 10.3389/fmicb.2023.1149145] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 03/29/2023] [Indexed: 05/28/2023] Open
Abstract
Acanthamoeba species, Naegleria fowleri, and Balamuthia mandrillaris are opportunistic pathogens that cause a range of brain, skin, eye, and disseminated diseases in humans and animals. These pathogenic free-living amoebae (pFLA) are commonly misdiagnosed and have sub-optimal treatment regimens which contribute to the extremely high mortality rates (>90%) when they infect the central nervous system. To address the unmet medical need for effective therapeutics, we screened kinase inhibitor chemotypes against three pFLA using phenotypic drug assays involving CellTiter-Glo 2.0. Herein, we report the activity of the compounds against the trophozoite stage of each of the three amoebae, ranging from nanomolar to low micromolar potency. The most potent compounds that were identified from this screening effort were: 2d (A. castellanii EC50: 0.92 ± 0.3 μM; and N. fowleri EC50: 0.43 ± 0.13 μM), 1c and 2b (N. fowleri EC50s: <0.63 μM, and 0.3 ± 0.21 μM), and 4b and 7b (B. mandrillaris EC50s: 1.0 ± 0.12 μM, and 1.4 ± 0.17 μM, respectively). With several of these pharmacophores already possessing blood-brain barrier (BBB) permeability properties, or are predicted to penetrate the BBB, these hits present novel starting points for optimization as future treatments for pFLA-caused diseases.
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Affiliation(s)
- Lori Ferrins
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, United States
| | - Melissa J. Buskes
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, United States
| | - Madison M. Kapteyn
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
| | - Hannah N. Engels
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
| | - Suzanne E. Enos
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA, United States
| | - Chenyang Lu
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN, United States
| | - Dana M. Klug
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, United States
| | - Baljinder Singh
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, United States
| | - Antonio Quotadamo
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, United States
- Clinical and Experimental Medicine PhD Program, University of Modena and Reggio Emilia, Modena, Italy
| | - Kelly Bachovchin
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, United States
| | - Westley F. Tear
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, United States
| | - Andrew E. Spaulding
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, United States
| | - Katherine C. Forbes
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, United States
| | - Seema Bag
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, United States
| | - Mitch Rivers
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, United States
| | - Catherine LeBlanc
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, United States
| | - Erin Burchfield
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, United States
| | - Jeremy R. Armand
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, United States
| | - Rosario Diaz-Gonzalez
- Instituto de Parasitología y Biomedicina “López-Neyra” Consejo Superior de Investigaciones Científicas (CSIC), Granada, Spain
| | - Gloria Ceballos-Perez
- Instituto de Parasitología y Biomedicina “López-Neyra” Consejo Superior de Investigaciones Científicas (CSIC), Granada, Spain
| | - Raquel García-Hernández
- Instituto de Parasitología y Biomedicina “López-Neyra” Consejo Superior de Investigaciones Científicas (CSIC), Granada, Spain
| | - Guiomar Pérez-Moreno
- Instituto de Parasitología y Biomedicina “López-Neyra” Consejo Superior de Investigaciones Científicas (CSIC), Granada, Spain
| | - Cristina Bosch-Navarrete
- Instituto de Parasitología y Biomedicina “López-Neyra” Consejo Superior de Investigaciones Científicas (CSIC), Granada, Spain
| | - Claudia Gómez-Liñán
- Instituto de Parasitología y Biomedicina “López-Neyra” Consejo Superior de Investigaciones Científicas (CSIC), Granada, Spain
| | - Luis Miguel Ruiz-Pérez
- Instituto de Parasitología y Biomedicina “López-Neyra” Consejo Superior de Investigaciones Científicas (CSIC), Granada, Spain
| | - Francisco Gamarro
- Instituto de Parasitología y Biomedicina “López-Neyra” Consejo Superior de Investigaciones Científicas (CSIC), Granada, Spain
| | - Dolores González-Pacanowska
- Instituto de Parasitología y Biomedicina “López-Neyra” Consejo Superior de Investigaciones Científicas (CSIC), Granada, Spain
| | - Miguel Navarro
- Instituto de Parasitología y Biomedicina “López-Neyra” Consejo Superior de Investigaciones Científicas (CSIC), Granada, Spain
| | - Kojo Mensa-Wilmot
- Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, GA, United States
| | - Michael P. Pollastri
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, United States
| | - Dennis E. Kyle
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
| | - Christopher A. Rice
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA, United States
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN, United States
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7
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Loufouma Mbouaka A, Lesiak-Markowicz I, Heredero-Bermejo I, Mazumdar R, Walochnik J, Martín-Pérez T. Assessing Acanthamoeba cytotoxicity: comparison of common cell viability assays. Front Microbiol 2023; 14:1175469. [PMID: 37180263 PMCID: PMC10167018 DOI: 10.3389/fmicb.2023.1175469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 04/03/2023] [Indexed: 05/16/2023] Open
Abstract
Background In vitro models for studying interactions between Acanthamoeba and host cells are crucial for understanding the pathomechanism of Acanthamoeba and assessing differences between strains and cell types. The virulence of Acanthamoeba strains is usually assessed and monitored by using cell cytotoxicity assays. The aim of the present study was to evaluate and compare the most widely used cytotoxicity assays for their suitability to assess Acanthamoeba cytopathogenicity. Methods The viability of human corneal epithelial cells (HCECs) after co-culture with Acanthamoeba was evaluated in phase contrast microscopy. Results It was shown that Acanthamoeba is unable to considerably reduce the tetrazolium salt and the NanoLuc® Luciferase prosubstrate to formazan and the luciferase substrate, respectively. This incapacity helped to generate a cell density-dependent signal allowing to accurately quantify Acanthamoeba cytotoxicity. The lactate dehydrogenase (LDH) assay led to an underestimation of the cytotoxic effect of Acanthamoeba on HCECs since their co-incubation negatively affected the lactate dehydrogenase activity. Discussion Our findings demonstrate that cell-based assays using the aqueous soluble tetrazolium-formazan, and the NanoLuc® Luciferase prosubstrate products, in contrast to LDH, are excellent markers to monitor the interaction of Acanthamoeba with human cell lines and to determine and quantify effectively the cytotoxic effect induced by the amoebae. Furthermore, our data indicate that protease activity may have an impact on the outcome and thus the reliability of these tests.
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Affiliation(s)
- Alvie Loufouma Mbouaka
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Iwona Lesiak-Markowicz
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Irene Heredero-Bermejo
- Department of Biomedicine and Biotechnology, Faculty of Pharmacy, University of Alcalá, Madrid, Spain
| | - Rounik Mazumdar
- Max Perutz Labs Vienna, Department of Medical Biochemistry, Medical University of Vienna, Vienna, Austria
| | - Julia Walochnik
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Tania Martín-Pérez
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
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8
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The 4-Aminomethylphenoxy-Benzoxaborole AN3057 as a Potential Treatment Option for Primary Amoebic Meningoencephalitis. Antimicrob Agents Chemother 2023; 67:e0150622. [PMID: 36688657 PMCID: PMC9933681 DOI: 10.1128/aac.01506-22] [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: 01/24/2023] Open
Abstract
Primary amoebic meningoencephalitis is a rare but fatal central nervous system (CNS) disease caused by the "brain-eating amoeba" Naegleria fowleri. A major obstacle is the requirement for drugs with the ability to cross the blood-brain barrier, which are used in extremely high doses, cause severe side effects, and are usually ineffective. We discovered that the 4-aminomethylphenoxy-benzoxaborole AN3057 exhibits nanomolar potency against N. fowleri, and experimental treatment of infected mice significantly prolonged survival and demonstrated a 28% relapse-free cure rate.
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9
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Cank KB, Shepherd RA, Knowles SL, Rangel-Grimaldo M, Raja HA, Bunch ZL, Cech NB, Rice CA, Kyle DE, Falkinham JO, Burdette JE, Oberlies NH. Polychlorinated cyclopentenes from a marine derived Periconia sp. (strain G1144). PHYTOCHEMISTRY 2022; 199:113200. [PMID: 35421431 PMCID: PMC9173697 DOI: 10.1016/j.phytochem.2022.113200] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 03/03/2022] [Accepted: 04/06/2022] [Indexed: 06/14/2023]
Abstract
Studies on an organic extract of a marine fungus, Periconia sp. (strain G1144), led to the isolation of three halogenated cyclopentenes along with the known and recently reported rhytidhyester D; a series of spectrometric and spectroscopic techniques were used to elucidate these structures. Interestingly, two of these compounds represent tri-halogenated cyclopentene derivatives, which have been observed only rarely from Nature. The relative and absolute configurations of the compounds were established via mass spectrometry (MS), nuclear magnetic resonance (NMR) spectroscopy, Mosher's esters method, optical rotation and GIAO NMR calculations, including correlation coefficient calculations and the use of both DP4+ and dJ DP4 analyses. Several of the isolated compounds were tested for activity in anti-parasitic, antimicrobial, quorum sensing inhibition, and cytotoxicity assays and were shown to be inactive.
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Affiliation(s)
- Kristóf B Cank
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, 435 Patricia A. Sullivan Science Building, Greensboro, NC, 27402-6170, USA
| | - Robert A Shepherd
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, 435 Patricia A. Sullivan Science Building, Greensboro, NC, 27402-6170, USA
| | - Sonja L Knowles
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, 435 Patricia A. Sullivan Science Building, Greensboro, NC, 27402-6170, USA
| | - Manuel Rangel-Grimaldo
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, 435 Patricia A. Sullivan Science Building, Greensboro, NC, 27402-6170, USA
| | - Huzefa A Raja
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, 435 Patricia A. Sullivan Science Building, Greensboro, NC, 27402-6170, USA
| | - Zoie L Bunch
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, 435 Patricia A. Sullivan Science Building, Greensboro, NC, 27402-6170, USA
| | - Nadja B Cech
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, 435 Patricia A. Sullivan Science Building, Greensboro, NC, 27402-6170, USA
| | - Christopher A Rice
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, 724 Biological Sciences Building, University of Georgia, Athens, GA, 30602-2607, USA; Center for Tropical and Emerging Global Diseases, University of Georgia, 335 Coverdell Center 500 D.W. Brooks Drive, Athens, GA, 30602-7399, USA.
| | - Dennis E Kyle
- Center for Tropical and Emerging Global Diseases, University of Georgia, 335 Coverdell Center 500 D.W. Brooks Drive, Athens, GA, 30602-7399, USA.
| | - Joseph O Falkinham
- Department of Biological Sciences, Virginia Tech Center for Drug Discovery, Derring Hall Room 2125, 926 West Campus Drive, Mail Code 0406, Blacksburg, VA, 24061, USA.
| | - Joanna E Burdette
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, 833 South Wood Street, 333 PHARM, MC 781, Chicago, IL, 60612, USA.
| | - Nicholas H Oberlies
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, 435 Patricia A. Sullivan Science Building, Greensboro, NC, 27402-6170, USA.
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10
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Novel 1, 2, 4-Triazoles as Antifungal Agents. BIOMED RESEARCH INTERNATIONAL 2022; 2022:4584846. [PMID: 35360519 PMCID: PMC8964166 DOI: 10.1155/2022/4584846] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 03/03/2022] [Indexed: 12/17/2022]
Abstract
The development of innovative antifungal agents is essential. Some fungicidal agents are no longer effective due to resistance development, various side effects, and high toxicity. Therefore, the synthesis and development of some new antifungal agents are necessary. 1,2,4-Triazole is one of the most essential pharmacophore systems between five-membered heterocycles. The structure-activity relationship (SAR) of this nitrogen-containing heterocyclic compound showed potential antifungal activity. The 1,2,4-triazole core is present as the nucleus in a variety of antifungal drug categories. The most potent and broad activity of triazoles have confirmed them as pharmacologically significant moieties. The goal of this review is to highlight recent developments in the synthesis and SAR study of 1,2,4-triazole as a potential fungicidal compound. In this study, we provide the results of a biological activity evaluation using various structures and figures. Literature investigation showed that 1, 2, 4-triazole derivatives reveal the extensive span of antifungal activity. This review will assist researchers in the development of new potential antifungal drug candidates with high effectiveness and selectivity.
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11
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Differential Growth Rates and In Vitro Drug Susceptibility to Currently Used Drugs for Multiple Isolates of Naegleria fowleri. Microbiol Spectr 2022; 10:e0189921. [PMID: 35138140 PMCID: PMC8826828 DOI: 10.1128/spectrum.01899-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The free-living amoeba Naegleria fowleri, which typically dwells within warm, freshwater environments, can opportunistically cause primary amoebic meningoencephalitis (PAM), a disease with a mortality rate of >97%. The lack of positive treatment outcomes for PAM has prompted the discovery and development of more effective therapeutics, yet most studies utilize only one or two clinical isolates. The inability to assess possible heterogenic responses to drugs among isolates from various geographical regions hinders progress in the discovery of more effective drugs. Here, we conducted drug efficacy and growth rate determinations for 11 different clinical isolates by applying a previously developed CellTiter-Glo 2.0 screening technique and flow cytometry. We found significant differences in the susceptibilities of these isolates to 7 of 8 drugs tested, all of which make up the cocktail that is recommended to physicians by the U.S. Centers for Disease Control and Prevention. We also discovered significant variances in growth rates among isolates, which draws attention to the differences among the amoeba isolates collected from different patients. Our results demonstrate the need for additional clinical isolates of various genotypes in drug assays and highlight the necessity for more targeted therapeutics with universal efficacy across N. fowleri isolates. Our data establish a needed baseline for drug susceptibility among clinical isolates and provide a segue for future combination therapy studies as well as research related to phenotypic or genetic differences that could shed light on mechanisms of action or predispositions to specific drugs. IMPORTANCENaegleria fowleri, also known as the brain-eating amoeba, is ubiquitous in warm freshwater and is an opportunistic pathogen that causes primary amoebic meningoencephalitis. Although few cases are described each year, the disease has a case fatality rate of >97%. In most laboratory studies of this organism, only one or two well-adapted lab strains are used; therefore, there is a lack of data to discern if there are major differences in potency of currently used drugs for multiple strains and genotypes of the amoeba. In this study, we found significant differences in the susceptibilities of 11 N. fowleri isolates to 7 of the 8 drugs currently used to treat the disease. The data from this study provide a baseline of drug susceptibility among clinical isolates and suggest that new drugs should be tested on a larger number of isolates in the future.
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Güémez A, García E. Primary Amoebic Meningoencephalitis by Naegleria fowleri: Pathogenesis and Treatments. Biomolecules 2021; 11:biom11091320. [PMID: 34572533 PMCID: PMC8469197 DOI: 10.3390/biom11091320] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 08/20/2021] [Accepted: 08/25/2021] [Indexed: 12/29/2022] Open
Abstract
Naegleria fowleri is a free-living amoeba (FLA) that is commonly known as the "brain-eating amoeba." This parasite can invade the central nervous system (CNS), causing an acute and fulminating infection known as primary amoebic meningoencephalitis (PAM). Even though PAM is characterized by low morbidity, it has shown a mortality rate of 98%, usually causing death in less than two weeks after the initial exposure. This review summarizes the most recent information about N. fowleri, its pathogenic molecular mechanisms, and the neuropathological processes implicated. Additionally, this review includes the main therapeutic strategies described in case reports and preclinical studies, including the possible use of immunomodulatory agents to decrease neurological damage.
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13
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EdU Incorporation To Assess Cell Proliferation and Drug Susceptibility in Naegleria fowleri. Antimicrob Agents Chemother 2021; 65:e0001721. [PMID: 33846135 DOI: 10.1128/aac.00017-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Naegleria fowleri is a pathogenic free-living amoeba that is commonly found in warm freshwater and can cause a rapidly fulminant disease known as primary amoebic meningoencephalitis (PAM). New drugs are urgently needed to treat PAM, as the fatality rate is >97%. Until recently, few advances have been made in the discovery of new drugs for N. fowleri, and one drawback is the lack of validated tools and methods to enhance drug discovery and diagnostics research. In this study, we aimed to validate alternative methods to assess cell proliferation that are commonly used for other cell types and develop a novel drug screening assay to evaluate drug efficacy on N. fowleri replication. EdU (5-ethynyl-2'-deoxyuridine) is a pyrimidine analog of thymidine that can be used as a quantitative endpoint for cell proliferation. EdU incorporation is detected via a copper catalyzed click reaction with an Alexa Fluor-linked azide. EdU incorporation in replicating N. fowleri was validated using fluorescence microscopy, and quantitative methods for assessing EdU incorporation were developed by using an imaging flow cytometer. Currently used PAM therapeutics inhibited N. fowleri replication and EdU incorporation in vitro. EdA (7-deaza-2'-deoxy-7-ethynyladenosine), an adenine analog, also was incorporated by N. fowleri but was more cytotoxic than EdU. In summary, EdU incorporation could be used as a complimentary method for drug discovery for these neglected pathogens.
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14
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Naegleria fowleri: Protein structures to facilitate drug discovery for the deadly, pathogenic free-living amoeba. PLoS One 2021; 16:e0241738. [PMID: 33760815 PMCID: PMC7990177 DOI: 10.1371/journal.pone.0241738] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 01/25/2021] [Indexed: 12/19/2022] Open
Abstract
Naegleria fowleri is a pathogenic, thermophilic, free-living amoeba which causes primary amebic meningoencephalitis (PAM). Penetrating the olfactory mucosa, the brain-eating amoeba travels along the olfactory nerves, burrowing through the cribriform plate to its destination: the brain’s frontal lobes. The amoeba thrives in warm, freshwater environments, with peak infection rates in the summer months and has a mortality rate of approximately 97%. A major contributor to the pathogen’s high mortality is the lack of sensitivity of N. fowleri to current drug therapies, even in the face of combination-drug therapy. To enable rational drug discovery and design efforts we have pursued protein production and crystallography-based structure determination efforts for likely drug targets from N. fowleri. The genes were selected if they had homology to drug targets listed in Drug Bank or were nominated by primary investigators engaged in N. fowleri research. In 2017, 178 N. fowleri protein targets were queued to the Seattle Structural Genomics Center of Infectious Disease (SSGCID) pipeline, and to date 89 soluble recombinant proteins and 19 unique target structures have been produced. Many of the new protein structures are potential drug targets and contain structural differences compared to their human homologs, which could allow for the development of pathogen-specific inhibitors. Five of the structures were analyzed in more detail, and four of five show promise that selective inhibitors of the active site could be found. The 19 solved crystal structures build a foundation for future work in combating this devastating disease by encouraging further investigation to stimulate drug discovery for this neglected pathogen.
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15
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Debnath A. Drug discovery for primary amebic meningoencephalitis: from screen to identification of leads. Expert Rev Anti Infect Ther 2021; 19:1099-1106. [PMID: 33496193 DOI: 10.1080/14787210.2021.1882302] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Introduction: Naegleria fowleri is responsible for primary amebic meningoencephalitis (PAM) which has a fatality rate of >97%. Because of the rarity of the disease, pharmaceutical companies do not pursue new drug discovery for PAM. Yet, it is possible that the infection is underreported and finding a better drug would have an impact on people suffering from this deadly infection.Areas covered: This paper reports the efforts undertaken by different academic groups over the last 20 years to test different compounds against N. fowleri. The drug discovery research encompassed synthesis of new compounds, development and use of high-throughput screening methods and attempts to repurpose clinically developed or FDA-approved compounds for the treatment of PAM.Expert opinion: In absence of economic investment to develop new drugs for PAM, repurposing the FDA-approved drugs has been the best strategy so far to identify new leads against N. fowleri. Increasing use of high-throughput phenotypic screening has the potential to accelerate the identification of new leads, either in monotherapy or in combination treatment. Since phase II clinical trial is not possible for PAM, it is critical to demonstrate in vivo efficacy of a clinically safe compound to translate the discovery from lab to the clinic.
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Affiliation(s)
- Anjan Debnath
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
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16
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Davis AM, Engkvist O, Fairclough RJ, Feierberg I, Freeman A, Iyer P. Public-Private Partnerships: Compound and Data Sharing in Drug Discovery and Development. SLAS DISCOVERY 2021; 26:604-619. [PMID: 33586501 DOI: 10.1177/2472555220982268] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Collaborative efforts between public and private entities such as academic institutions, governments, and pharmaceutical companies form an integral part of scientific research, and notable instances of such initiatives have been created within the life science community. Several examples of alliances exist with the broad goal of collaborating toward scientific advancement and improved public welfare. Such collaborations can be essential in catalyzing breaking areas of science within high-risk or global public health strategies that may have otherwise not progressed. A common term used to describe these alliances is public-private partnership (PPP). This review discusses different aspects of such partnerships in drug discovery/development and provides example applications as well as successful case studies. Specific areas that are covered include PPPs for sharing compounds at various phases of the drug discovery process-from compound collections for hit identification to sharing clinical candidates. Instances of PPPs to support better data integration and build better machine learning models are also discussed. The review also provides examples of PPPs that address the gap in knowledge or resources among involved parties and advance drug discovery, especially in disease areas with unfulfilled and/or social needs, like neurological disorders, cancer, and neglected and rare diseases.
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Affiliation(s)
- Andrew M Davis
- Hit Discovery, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Ola Engkvist
- Molecular AI, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Rebecca J Fairclough
- Emerging Innovations Unit, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Isabella Feierberg
- Molecular AI, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Boston, USA
| | - Adrian Freeman
- Emerging Innovations Unit, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Preeti Iyer
- Molecular AI, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
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17
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Rice CA, Colon BL, Chen E, Hull MV, Kyle DE. Discovery of repurposing drug candidates for the treatment of diseases caused by pathogenic free-living amoebae. PLoS Negl Trop Dis 2020; 14:e0008353. [PMID: 32970675 PMCID: PMC7546510 DOI: 10.1371/journal.pntd.0008353] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 10/09/2020] [Accepted: 07/28/2020] [Indexed: 12/11/2022] Open
Abstract
Diseases caused by pathogenic free-living amoebae include primary amoebic meningoencephalitis (Naegleria fowleri), granulomatous amoebic encephalitis (Acanthamoeba spp.), Acanthamoeba keratitis, and Balamuthia amoebic encephalitis (Balamuthia mandrillaris). Each of these are difficult to treat and have high morbidity and mortality rates due to lack of effective therapeutics. Since repurposing drugs is an ideal strategy for orphan diseases, we conducted a high throughput phenotypic screen of 12,000 compounds from the Calibr ReFRAME library. We discovered a total of 58 potent inhibitors (IC50 <1 μM) against N. fowleri (n = 19), A. castellanii (n = 12), and B. mandrillaris (n = 27) plus an additional 90 micromolar inhibitors. Of these, 113 inhibitors have never been reported to have activity against Naegleria, Acanthamoeba or Balamuthia. Rapid onset of action is important for new anti-amoeba drugs and we identified 19 compounds that inhibit N. fowleri in vitro within 24 hours (halofuginone, NVP-HSP990, fumagillin, bardoxolone, belaronib, and BPH-942, solithromycin, nitracrine, quisinostat, pabinostat, pracinostat, dacinostat, fimepinostat, sanguinarium, radicicol, acriflavine, REP3132, BC-3205 and PF-4287881). These compounds inhibit N. fowleri in vitro faster than any of the drugs currently used for chemotherapy. The results of these studies demonstrate the utility of phenotypic screens for discovery of new drugs for pathogenic free-living amoebae, including Acanthamoeba for the first time. Given that many of the repurposed drugs have known mechanisms of action, these compounds can be used to validate new targets for structure-based drug design.
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Affiliation(s)
- Christopher A. Rice
- Department of Cellular Biology, University of Georgia, Athens, Georgia, United States of America
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
- * E-mail: (CAR); (DEK)
| | - Beatrice L. Colon
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, United States of America
| | - Emily Chen
- Calibr at Scripps Research, La Jolla, California, United States of America
| | - Mitchell V. Hull
- Calibr at Scripps Research, La Jolla, California, United States of America
| | - Dennis E. Kyle
- Department of Cellular Biology, University of Georgia, Athens, Georgia, United States of America
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, United States of America
- * E-mail: (CAR); (DEK)
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18
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Inhibition of Fatty Acid Oxidation as a New Target To Treat Primary Amoebic Meningoencephalitis. Antimicrob Agents Chemother 2020; 64:AAC.00344-20. [PMID: 32513800 PMCID: PMC7526813 DOI: 10.1128/aac.00344-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 06/03/2020] [Indexed: 12/20/2022] Open
Abstract
Primary amoebic meningoencephalitis (PAM) is a rapidly fatal infection caused by the free-living amoeba Naegleria fowleri. The amoeba migrates along the olfactory nerve to the brain, resulting in seizures, coma, and, eventually, death. Previous research has shown that Naegleria gruberi, a close relative of N. fowleri, prefers lipids over glucose as an energy source. Therefore, we tested several already-approved inhibitors of fatty acid oxidation alongside the currently used drugs amphotericin B and miltefosine. Primary amoebic meningoencephalitis (PAM) is a rapidly fatal infection caused by the free-living amoeba Naegleria fowleri. The amoeba migrates along the olfactory nerve to the brain, resulting in seizures, coma, and, eventually, death. Previous research has shown that Naegleria gruberi, a close relative of N. fowleri, prefers lipids over glucose as an energy source. Therefore, we tested several already-approved inhibitors of fatty acid oxidation alongside the currently used drugs amphotericin B and miltefosine. Our data demonstrate that etomoxir, orlistat, perhexiline, thioridazine, and valproic acid inhibited growth of N. gruberi. We then tested these compounds on N. fowleri and found etomoxir, perhexiline, and thioridazine to be effective growth inhibitors. Hence, not only are lipids the preferred food source for N. gruberi, but also oxidation of fatty acids seems to be essential for growth of N. fowleri. Inhibition of fatty acid oxidation could result in new treatment options, as thioridazine inhibits N. fowleri growth in concentrations that can be reached at the site of infection. It could also potentiate currently used therapy, as checkerboard assays revealed synergy between miltefosine and etomoxir. Animal testing should be performed to confirm the added value of these inhibitors. Although the development of new drugs and randomized controlled trials for this rare disease are nearly impossible, inhibition of fatty acid oxidation seems a promising strategy as we showed effectivity of several drugs that are or have been in use and that thus could be repurposed to treat PAM in the future.
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Rice CA, Troth EV, Russell AC, Kyle DE. Discovery of Anti-Amoebic Inhibitors from Screening the MMV Pandemic Response Box on Balamuthia mandrillaris, Naegleria fowleri, and Acanthamoeba castellanii. Pathogens 2020; 9:E476. [PMID: 32560115 PMCID: PMC7344389 DOI: 10.3390/pathogens9060476] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/05/2020] [Accepted: 06/09/2020] [Indexed: 02/06/2023] Open
Abstract
Pathogenic free-living amoebae, Balamuthia mandrillaris, Naegleria fowleri, and several Acanthamoeba species are the etiological agents of severe brain diseases, with case mortality rates > 90%. A number of constraints including misdiagnosis and partially effective treatments lead to these high fatality rates. The unmet medical need is for rapidly acting, highly potent new drugs to reduce these alarming mortality rates. Herein, we report the discovery of new drugs as potential anti-amoebic agents. We used the CellTiter-Glo 2.0 high-throughput screening methods to screen the Medicines for Malaria Ventures (MMV) Pandemic Response Box in a search for new active chemical scaffolds. Initially, we screened the library as a single-point assay at 10 and 1 µM. From these data, we reconfirmed hits by conducting quantitative dose-response assays and identified 12 hits against B. mandrillaris, 29 against N. fowleri, and 14 against A. castellanii ranging from nanomolar to low micromolar potency. We further describe 11 novel molecules with activity against B. mandrillaris, 22 against N. fowleri, and 9 against A. castellanii. These structures serve as a starting point for medicinal chemistry studies and demonstrate the utility of phenotypic screening for drug discovery to treat diseases caused by free-living amoebae.
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Affiliation(s)
- Christopher A. Rice
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
- Center for Tropical and Emerging Global Diseases, Athens, GA 30602, USA; (E.V.T.); (A.C.R.)
| | - Emma V. Troth
- Center for Tropical and Emerging Global Diseases, Athens, GA 30602, USA; (E.V.T.); (A.C.R.)
- Department of Infectious Diseases, University of Georgia, Athens, GA 30602, USA
| | - A. Cassiopeia Russell
- Center for Tropical and Emerging Global Diseases, Athens, GA 30602, USA; (E.V.T.); (A.C.R.)
- Department of Infectious Diseases, University of Georgia, Athens, GA 30602, USA
| | - Dennis E. Kyle
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
- Center for Tropical and Emerging Global Diseases, Athens, GA 30602, USA; (E.V.T.); (A.C.R.)
- Department of Infectious Diseases, University of Georgia, Athens, GA 30602, USA
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20
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In Vitro Screening of the Open-Source Medicines for Malaria Venture Malaria and Pathogen Boxes To Discover Novel Compounds with Activity against Balamuthia mandrillaris. Antimicrob Agents Chemother 2020; 64:AAC.02233-19. [PMID: 32071043 DOI: 10.1128/aac.02233-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 02/07/2020] [Indexed: 11/20/2022] Open
Abstract
Balamuthia mandrillaris is an under-reported, pathogenic free-living amoeba that causes Balamuthia amoebic encephalitis (BAE) and cutaneous skin infections. Although cutaneous infections are not typically lethal, BAE with or without cutaneous involvement is usually fatal. This is due to the lack of drugs that are both efficacious and can cross the blood-brain barrier. We aimed to discover new leads for drug discovery by screening the open-source Medicines for Malaria Venture (MMV) Malaria Box and MMV Pathogen Box, with 800 compounds total. From an initial single point screen at 1 and 10 μM, we identified 54 hits that significantly inhibited the growth of B. mandrillaris in vitro Hits were reconfirmed in quantitative dose-response assays and 23 compounds (42.6%) were confirmed with activity greater than miltefosine, the current standard of care.
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21
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Kangussu-Marcolino MM, Ehrenkaufer GM, Chen E, Debnath A, Singh U. Identification of plicamycin, TG02, panobinostat, lestaurtinib, and GDC-0084 as promising compounds for the treatment of central nervous system infections caused by the free-living amebae Naegleria, Acanthamoeba and Balamuthia. Int J Parasitol Drugs Drug Resist 2019; 11:80-94. [PMID: 31707263 PMCID: PMC6849155 DOI: 10.1016/j.ijpddr.2019.10.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/18/2019] [Accepted: 10/17/2019] [Indexed: 01/11/2023]
Abstract
The free-living amebae Naegleria, Acanthamoeba, and Balamuthia cause rare but life-threatening infections. All three parasites can cause meningoencephalitis. Acanthamoeba can also cause chronic keratitis and both Balamuthia and Acanthamoeba can cause skin and systemic infections. There are minimal drug development pipelines for these pathogens despite a lack of available treatment regimens and high fatality rates. To identify anti-amebic drugs, we screened 159 compounds from a high-value repurposed library against trophozoites of the three amebae. Our efforts identified 38 compounds with activity against at least one ameba. Multiple drugs that bind the ATP-binding pocket of mTOR and PI3K are active, highlighting these compounds as important inhibitors of these parasites. Importantly, 24 active compounds have progressed at least to phase II clinical studies and overall 15 compounds were active against all three amebae. Based on central nervous system (CNS) penetration or exceptional potency against one amebic species, we identified sixteen priority compounds for the treatment of meningoencephalitis caused by these pathogens. The top five compounds are (i) plicamycin, active against all three free-living amebae and previously U.S. Food and Drug Administration (FDA) approved, (ii) TG02, active against all three amebae, (iii and iv) FDA-approved panobinostat and FDA orphan drug lestaurtinib, both highly potent against Naegleria, and (v) GDC-0084, a CNS penetrant mTOR inhibitor, active against at least two of the three amebae. These results set the stage for further investigation of these clinically advanced compounds for treatment of infections caused by the free-living amebae, including treatment of the highly fatal meningoencephalitis.
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Affiliation(s)
- Monica M Kangussu-Marcolino
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University, Grant Building, S-143, 300 Pasteur Drive, Stanford, CA, 94305, USA
| | - Gretchen M Ehrenkaufer
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University, Grant Building, S-143, 300 Pasteur Drive, Stanford, CA, 94305, USA
| | - Emily Chen
- uHTS Laboratory Rm 101, 11119 N Torrey Pines Rd. Calibr, A Division of the Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Anjan Debnath
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Upinder Singh
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University, Grant Building, S-143, 300 Pasteur Drive, Stanford, CA, 94305, USA; Department of Microbiology and Immunology, Stanford University, Stanford, CA, 94305, USA.
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22
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Vareechon C, Tarro T, Polanco C, Anand V, Pannaraj PS, Dien Bard J. Eight-Year-Old Male With Primary Amebic Meningoencephalitis. Open Forum Infect Dis 2019; 6:ofz349. [PMID: 31660390 PMCID: PMC6735792 DOI: 10.1093/ofid/ofz349] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 07/26/2019] [Indexed: 11/23/2022] Open
Abstract
Naegleria fowleri is a thermophilic free-living amoeba that is found in warm, fresh water and causes primary amebic meningoencephalitis (PAM). The following report demonstrates the rapid and destructive clinical features of PAM in an 8-year-old male who presented with severe headaches approximately 12 days after swimming in a hot spring.
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Affiliation(s)
- Chairut Vareechon
- Department of Pathology and Laboratory Medicine, Children's Hospital Los Angeles, California
| | - Thomas Tarro
- Department of Infectious Disease, Children's Hospital Los Angeles, California.,Keck School of Medicine, University of Southern California, Los Angeles
| | - Claudia Polanco
- Department of Pathology and Laboratory Medicine, Children's Hospital Los Angeles, California
| | - Vikram Anand
- Department of Infectious Disease, Children's Hospital Los Angeles, California.,Keck School of Medicine, University of Southern California, Los Angeles
| | - Pia S Pannaraj
- Department of Infectious Disease, Children's Hospital Los Angeles, California.,Keck School of Medicine, University of Southern California, Los Angeles
| | - Jennifer Dien Bard
- Department of Pathology and Laboratory Medicine, Children's Hospital Los Angeles, California.,Keck School of Medicine, University of Southern California, Los Angeles
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