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Stadler E, Maiga M, Friedrich L, Thathy V, Demarta-Gatsi C, Dara A, Sogore F, Striepen J, Oeuvray C, Djimdé AA, Lee MCS, Dembélé L, Fidock DA, Khoury DS, Spangenberg T. Propensity of selecting mutant parasites for the antimalarial drug cabamiquine. Nat Commun 2023; 14:5205. [PMID: 37626093 PMCID: PMC10457284 DOI: 10.1038/s41467-023-40974-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 08/17/2023] [Indexed: 08/27/2023] Open
Abstract
We report an analysis of the propensity of the antimalarial agent cabamiquine, a Plasmodium-specific eukaryotic elongation factor 2 inhibitor, to select for resistant Plasmodium falciparum parasites. Through in vitro studies of laboratory strains and clinical isolates, a humanized mouse model, and volunteer infection studies, we identified resistance-associated mutations at 11 amino acid positions. Of these, six (55%) were present in more than one infection model, indicating translatability across models. Mathematical modelling suggested that resistant mutants were likely pre-existent at the time of drug exposure across studies. Here, we estimated a wide range of frequencies of resistant mutants across the different infection models, much of which can be attributed to stochastic differences resulting from experimental design choices. Structural modelling implicates binding of cabamiquine to a shallow mRNA binding site adjacent to two of the most frequently identified resistance mutations.
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Affiliation(s)
- Eva Stadler
- The Kirby Institute, UNSW Sydney, Kensington, NSW, 2052, Australia
| | - Mohamed Maiga
- Université des Sciences, des Techniques et des Technologies de Bamako (USTTB), Faculté de Pharmacie, Malaria Research and Training Center (MRTC), Point G, PB1805, Bamako, Mali
| | - Lukas Friedrich
- Medicinal Chemistry & Drug Design Global Research & Development, Discovery Technologies, Merck Healthcare, 64293, Darmstadt, Germany
| | - Vandana Thathy
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
- Center for Malaria Therapeutics and Antimicrobial Resistance, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Claudia Demarta-Gatsi
- Global Health Institute of Merck, Ares Trading S.A., (an affiliate of Merck KGaA, Darmstadt, Germany), 1262, Eysins, Switzerland
| | - Antoine Dara
- Université des Sciences, des Techniques et des Technologies de Bamako (USTTB), Faculté de Pharmacie, Malaria Research and Training Center (MRTC), Point G, PB1805, Bamako, Mali
| | - Fanta Sogore
- Université des Sciences, des Techniques et des Technologies de Bamako (USTTB), Faculté de Pharmacie, Malaria Research and Training Center (MRTC), Point G, PB1805, Bamako, Mali
| | - Josefine Striepen
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
- Weill Cornell Medical College, New York, NY, 10021, USA
| | - Claude Oeuvray
- Global Health Institute of Merck, Ares Trading S.A., (an affiliate of Merck KGaA, Darmstadt, Germany), 1262, Eysins, Switzerland
| | - Abdoulaye A Djimdé
- Université des Sciences, des Techniques et des Technologies de Bamako (USTTB), Faculté de Pharmacie, Malaria Research and Training Center (MRTC), Point G, PB1805, Bamako, Mali
| | - Marcus C S Lee
- Wellcome Sanger Institute, Wellcome Genome Campus, CB10 1SA, Hinxton, UK
- Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, DD1 4HN, Scotland, UK
| | - Laurent Dembélé
- Université des Sciences, des Techniques et des Technologies de Bamako (USTTB), Faculté de Pharmacie, Malaria Research and Training Center (MRTC), Point G, PB1805, Bamako, Mali.
| | - David A Fidock
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA.
- Center for Malaria Therapeutics and Antimicrobial Resistance, Columbia University Irving Medical Center, New York, NY, 10032, USA.
- Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, NY, 10032, USA.
| | - David S Khoury
- The Kirby Institute, UNSW Sydney, Kensington, NSW, 2052, Australia.
| | - Thomas Spangenberg
- Global Health Institute of Merck, Ares Trading S.A., (an affiliate of Merck KGaA, Darmstadt, Germany), 1262, Eysins, Switzerland.
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2
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Aniweh Y, Soulama A, Chirawurah J, Ansah F, Danwonno HA, Sogore F, Rouillier M, Campo B, Amenga-Etego L, Djimde AA, Awandare GA, Dembele L. Comparative Susceptibility of Plasmodium ovale and Plasmodium falciparum Field Isolates to Reference and Lead Candidate Antimalarial Drugs in Ghana. Microbiol Spectr 2023; 11:e0491622. [PMID: 37093000 PMCID: PMC10269539 DOI: 10.1128/spectrum.04916-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 03/30/2023] [Indexed: 04/25/2023] Open
Abstract
Malaria treatments resulted in the decline of the deadliest Plasmodium falciparum globally while species, such as P. ovale, infections have been increasingly detected across sub-Saharan Africa. Currently, no experimental drug sensitivity data are available to guide effective treatment and management of P. ovale infections, which is necessary for effective malaria elimination. We conducted a prospective study to evaluate P. ovale epidemiology over 1 year and determined ex vivo susceptibility of the field isolates to existing and lead advanced discovery antimalarial drugs. We report that while P. falciparum dominated both symptomatic and asymptomatic malaria cases, P. ovale in mono or co-infections caused 7.16% of symptomatic malaria. Frontline antimalarials artesunate and lumefantrine inhibited P. ovale as potently as P. falciparum. Chloroquine, which has been withdrawn in Ghana, was also highly inhibitory against both P. ovale and P. falciparum. In addition, P. ovale and P. falciparum displayed high susceptibility to quinine, comparable to levels observed with chloroquine. Pyrimethamine, which is a major drug for disease massive prevention, also showed great inhibition of P. ovale, comparable to effects on P. falciparum. Furthermore, we identified strong inhibition of P. ovale using GNF179, a close analogue of KAF156 imidazolopiperazines, which is a novel class of antimalarial drugs currently in clinical phase II testing. We further demonstrated that the Plasmodium phosphatidylinositol-4-OH kinase (PI4K)-specific inhibitor, KDU691, is highly inhibitory against P. ovale and P. falciparum field isolates. Our data indicated that existing and lead advanced discovery antimalarial drugs are suitable for the treatment of P. ovale infections in Ghana. IMPORTANCE Current malaria control and elimination tools such as drug treatments are not specifically targeting P.ovale. P. ovale can form hypnozoite and cause relapsing malaria. P. ovale is the third most dominant species in Africa and requires radical cure treatment given that it can form liver dormant forms called hypnozoites that escape all safe treatments. The inappropriate treatment of P. ovale would sustain its transmission in Africa where the medical need is the greatest. This is a hurdle for successful malaria control and elimination. Here, we provided experiment data that were lacking to guide P. ovale treatment and disease control policy makers using reference antimalarial drugs. We also provided key experimental data for 2 clinical candidate drugs that can be used for prioritization selection of lead candidate's identification for clinical development.
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Affiliation(s)
- Yaw Aniweh
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
| | - Alamissa Soulama
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
| | - Jersley Chirawurah
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
| | - Felix Ansah
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
| | - Harry A. Danwonno
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
| | - Fanta Sogore
- Malaria Research and Training Centre (MRTC), Faculty of Pharmacy, Université des Sciences, des Techniques et des Technologies de Bamako (USTTB), Point G, Bamako, Mali
| | | | - Brice Campo
- Medicines for Malaria Venture (MMV), Geneva, Switzerland
| | - Lucas Amenga-Etego
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
| | - Abdoulaye A. Djimde
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
| | - Gordon A. Awandare
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
| | - Laurent Dembele
- Malaria Research and Training Centre (MRTC), Faculty of Pharmacy, Université des Sciences, des Techniques et des Technologies de Bamako (USTTB), Point G, Bamako, Mali
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3
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Abstract
INTRODUCTION The deployment of Artemisinin-based combination therapies and transmission control measures led to a decrease in the global malaria burden over the recent decades. Unfortunately, this trend is now reversing, in part due to resistance against available treatments, calling for the development of new drugs against untapped targets to prevent cross-resistance. AREAS COVERED In view of their demonstrated druggability in noninfectious diseases, protein kinases represent attractive targets. Kinase-focussed antimalarial drug discovery is facilitated by the availability of kinase-targeting scaffolds and large libraries of inhibitors, as well as high-throughput phenotypic and biochemical assays. We present an overview of validated Plasmodium kinase targets and their inhibitors, and briefly discuss the potential of host cell kinases as targets for host-directed therapy. EXPERT OPINION We propose priority research areas, including (i) diversification of Plasmodium kinase targets (at present most efforts focus on a very small number of targets); (ii) polypharmacology as an avenue to limit resistance (kinase inhibitors are highly suitable in this respect); and (iii) preemptive limitation of resistance through host-directed therapy (targeting host cell kinases that are required for parasite survival) and transmission-blocking through targeting sexual stage-specific kinases as a strategy to protect curative drugs from the spread of resistance.
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Affiliation(s)
- Han Wee Ong
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC USA
| | - Jack Adderley
- Department of Laboratory Medicine, School of Health and Biomedical Sciences, Rmit University, Bundoora VIC Australia
| | - Andrew B Tobin
- Advanced Research Centre, University of Glasgow, Glasgow, UK
| | - David H Drewry
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC USA
| | - Christian Doerig
- Department of Laboratory Medicine, School of Health and Biomedical Sciences, Rmit University, Bundoora VIC Australia
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4
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Borba JVVB, Silva ADCE, do Nascimento MN, Ferreira LT, Rimoldi A, Starling L, Ramos PIP, Costa FTM, Andrade CH. Update and elucidation of Plasmodium kinomes: Prioritization of kinases as potential drug targets for malaria. Comput Struct Biotechnol J 2022; 20:3708-3717. [PMID: 35891792 PMCID: PMC9293725 DOI: 10.1016/j.csbj.2022.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 07/01/2022] [Accepted: 07/02/2022] [Indexed: 12/05/2022] Open
Abstract
Malaria is a tropical disease caused by Plasmodium spp. and transmitted by the bite of infected Anopheles mosquitoes. Protein kinases (PKs) play key roles in the life cycle of the etiological agent of malaria, turning these proteins attractive targets for antimalarial drug discovery campaigns. As part of an effort to understand parasite signaling functions, we report the results of a bioinformatics pipeline analysis of PKs of eight Plasmodium species. To date, no P. malariae and P. ovale kinome assemble has been conducted. We classified, curated and annotated predicted kinases to update P. falciparum, P. vivax, P. yoelii, P. berghei, P. chabaudi, and P. knowlesi kinomes published to date, as well as report for the first time the kinomes of P. malariae and P. ovale. Overall, from 76 to 97 PKs were identified among all Plasmodium spp. kinomes. Most of the kinases were assigned to seven of nine major kinase groups: AGC, CAMK, CMGC, CK1, STE, TKL, OTHER; and the Plasmodium-specific group FIKK. About 30% of kinases have been deeply classified into group, family and subfamily levels and only about 10% remained unclassified. Furthermore, updating and comparing the kinomes of P. vivax and P. falciparum allowed for the prioritization and selection of kinases as potential drug targets that could be explored for discovering new drugs against malaria. This integrated approach resulted in the selection of 37 protein kinases as potential targets and the identification of investigational compounds with moderate in vitro activity against asexual P. falciparum (3D7 and Dd2 strains) stages that could serve as starting points for the search of potent antimalarial leads in the future.
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Affiliation(s)
- Joyce Villa Verde Bastos Borba
- LabMol - Laboratory for Molecular Modeling and Drug Design, Faculdade de Farmácia, Universidade Federal de Goiás (UFG), Goiânia, Brazil.,Laboratory of Tropical Diseases - Prof. Dr. Luiz Jacintho da Silva, Department of Genetics Evolution, Microbiology and Immunology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Arthur de Carvalho E Silva
- LabMol - Laboratory for Molecular Modeling and Drug Design, Faculdade de Farmácia, Universidade Federal de Goiás (UFG), Goiânia, Brazil
| | - Marília Nunes do Nascimento
- LabMol - Laboratory for Molecular Modeling and Drug Design, Faculdade de Farmácia, Universidade Federal de Goiás (UFG), Goiânia, Brazil
| | - Letícia Tiburcio Ferreira
- Laboratory of Tropical Diseases - Prof. Dr. Luiz Jacintho da Silva, Department of Genetics Evolution, Microbiology and Immunology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Aline Rimoldi
- Laboratory of Tropical Diseases - Prof. Dr. Luiz Jacintho da Silva, Department of Genetics Evolution, Microbiology and Immunology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Luísa Starling
- LabMol - Laboratory for Molecular Modeling and Drug Design, Faculdade de Farmácia, Universidade Federal de Goiás (UFG), Goiânia, Brazil
| | | | - Fabio Trindade Maranhão Costa
- Laboratory of Tropical Diseases - Prof. Dr. Luiz Jacintho da Silva, Department of Genetics Evolution, Microbiology and Immunology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Carolina Horta Andrade
- LabMol - Laboratory for Molecular Modeling and Drug Design, Faculdade de Farmácia, Universidade Federal de Goiás (UFG), Goiânia, Brazil.,Laboratory of Tropical Diseases - Prof. Dr. Luiz Jacintho da Silva, Department of Genetics Evolution, Microbiology and Immunology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil
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5
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Dembele L, Diallo N, Sogore F, Diarra B, Ballo FI, Daou A, Diakite O, Bare Y, Sangare CPO, Haidara AS, Diakite SAS, Niangaly A, Diakite M, Campo B, Awandare GA, Aniweh Y, Djimde AA. Ex Vivo Plasmodium malariae Culture Method for Antimalarial Drugs Screen in the Field. ACS Infect Dis 2021; 7:3025-3033. [PMID: 34711047 PMCID: PMC9974065 DOI: 10.1021/acsinfecdis.1c00262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In vitro and ex vivo cultivation of Plasmodium (P) falciparum has facilitated active research into the malaria parasite toward the quest for basic knowledge and the discovery of effective drug treatments. Such a drug discovery program is currently difficult for P. malariae simply because of the absence of in vitro and ex vivo cultivation system for its asexual blood stages supporting antimalarial evaluation. Despite availability of artemisinin combination therapies effective on P. falciparum, P. malariae is being increasingly detected in malaria endemic countries. P. malariae is responsible for chronic infections and is associated with a high burden of anemia and morbidity. Here, we optimized and adapted ex vivo conditions under which P. malariae can be cultured and used for screening antimalarial drugs. Subsequently, this enabled us to test compounds such as artemether, chloroquine, lumefantrine, and quinine for ex vivo antimalarial activity against P. malariae.
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Affiliation(s)
- Laurent Dembele
- Faculté
de Pharmacie, Malaria Research and Training Center (MRTC), Université des Sciences des Techniques et des
Technologies de Bamako, Point G, Postal Box 1805, Bamako, Mali,
| | - Nouhoum Diallo
- Faculté
de Pharmacie, Malaria Research and Training Center (MRTC), Université des Sciences des Techniques et des
Technologies de Bamako, Point G, Postal Box 1805, Bamako, Mali
| | - Fanta Sogore
- Faculté
de Pharmacie, Malaria Research and Training Center (MRTC), Université des Sciences des Techniques et des
Technologies de Bamako, Point G, Postal Box 1805, Bamako, Mali
| | - Bintou Diarra
- Faculté
de Pharmacie, Malaria Research and Training Center (MRTC), Université des Sciences des Techniques et des
Technologies de Bamako, Point G, Postal Box 1805, Bamako, Mali
| | - Fatoumata I. Ballo
- Faculté
de Pharmacie, Malaria Research and Training Center (MRTC), Université des Sciences des Techniques et des
Technologies de Bamako, Point G, Postal Box 1805, Bamako, Mali
| | - Amadou Daou
- Faculté
de Pharmacie, Malaria Research and Training Center (MRTC), Université des Sciences des Techniques et des
Technologies de Bamako, Point G, Postal Box 1805, Bamako, Mali
| | - Ousmaila Diakite
- Faculté
de Pharmacie, Malaria Research and Training Center (MRTC), Université des Sciences des Techniques et des
Technologies de Bamako, Point G, Postal Box 1805, Bamako, Mali
| | - Yacouba Bare
- Faculté
de Pharmacie, Malaria Research and Training Center (MRTC), Université des Sciences des Techniques et des
Technologies de Bamako, Point G, Postal Box 1805, Bamako, Mali
| | - Cheick Papa Oumar Sangare
- Faculté
de Pharmacie, Malaria Research and Training Center (MRTC), Université des Sciences des Techniques et des
Technologies de Bamako, Point G, Postal Box 1805, Bamako, Mali
| | - Aboubecrin Sedhigh Haidara
- Faculté
de Pharmacie, Malaria Research and Training Center (MRTC), Université des Sciences des Techniques et des
Technologies de Bamako, Point G, Postal Box 1805, Bamako, Mali
| | - Seidina A. S. Diakite
- Faculté
de Pharmacie, Malaria Research and Training Center (MRTC), Université des Sciences des Techniques et des
Technologies de Bamako, Point G, Postal Box 1805, Bamako, Mali
| | - Amadou Niangaly
- Faculté
de Pharmacie, Malaria Research and Training Center (MRTC), Université des Sciences des Techniques et des
Technologies de Bamako, Point G, Postal Box 1805, Bamako, Mali
| | - Mahamadou Diakite
- Faculté
de Pharmacie, Malaria Research and Training Center (MRTC), Université des Sciences des Techniques et des
Technologies de Bamako, Point G, Postal Box 1805, Bamako, Mali
| | - Brice Campo
- Medicines
for Malaria Venture (MMV), ICC Building Entrance G Third Floor Route de Pré-Bois 20 Postal Box 1826 CH-1215 Geneva
15 Switzerland
| | - Gordon A. Awandare
- West
African Centre for Cell Biology of Infectious Pathogens (WACCBIP),
Department of Biochemistry, Cell and Molecular Biology, College of
Basic and Applied Sciences, University of
Ghana, LG 54 Legon, Accra, Ghana
| | - Yaw Aniweh
- West
African Centre for Cell Biology of Infectious Pathogens (WACCBIP),
Department of Biochemistry, Cell and Molecular Biology, College of
Basic and Applied Sciences, University of
Ghana, LG 54 Legon, Accra, Ghana
| | - Abdoulaye A. Djimde
- Faculté
de Pharmacie, Malaria Research and Training Center (MRTC), Université des Sciences des Techniques et des
Technologies de Bamako, Point G, Postal Box 1805, Bamako, Mali,
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6
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Erhunse N, Sahal D. Protecting future antimalarials from the trap of resistance: Lessons from artemisinin-based combination therapy (ACT) failures. J Pharm Anal 2021; 11:541-554. [PMID: 34765267 PMCID: PMC8572664 DOI: 10.1016/j.jpha.2020.07.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 07/19/2020] [Accepted: 07/19/2020] [Indexed: 11/01/2022] Open
Abstract
Having faced increased clinical treatment failures with dihydroartemisinin-piperaquine (DHA-PPQ), Cambodia swapped the first line artemisinin-based combination therapy (ACT) from DHA-PPQ to artesunate-mefloquine given that parasites resistant to piperaquine are susceptible to mefloquine. However, triple mutants have now emerged, suggesting that drug rotations may not be adequate to keep resistance at bay. There is, therefore, an urgent need for alternative treatment strategies to tackle resistance and prevent its spread. A proper understanding of all contributors to artemisinin resistance may help us identify novel strategies to keep artemisinins effective until new drugs become available for their replacement. This review highlights the role of the key players in artemisinin resistance, the current strategies to deal with it and suggests ways of protecting future antimalarial drugs from bowing to resistance as their predecessors did.
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Affiliation(s)
- Nekpen Erhunse
- Malaria Drug Discovery Research Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, 110067, India
- Department of Biochemistry, Faculty of Life Sciences, University of Benin, Benin City, Edo-State, Nigeria
| | - Dinkar Sahal
- Malaria Drug Discovery Research Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, 110067, India
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7
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Dembele L, Aniweh Y, Diallo N, Sogore F, Sangare CPO, Haidara AS, Traore A, Diakité SAS, Diakite M, Campo B, Awandare GA, Djimde AA. Plasmodium malariae and Plasmodium falciparum comparative susceptibility to antimalarial drugs in Mali. J Antimicrob Chemother 2021; 76:2079-2087. [PMID: 34021751 DOI: 10.1093/jac/dkab133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 03/16/2021] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES To evaluate Plasmodium malariae susceptibility to current and lead candidate antimalarial drugs. METHODS We conducted cross-sectional screening and detection of all Plasmodium species malaria cases, which were nested within a longitudinal prospective study, and an ex vivo assessment of efficacy of a panel of antimalarials against P. malariae and Plasmodium falciparum, both PCR-confirmed mono-infections. Reference compounds tested included chloroquine, lumefantrine, artemether and piperaquine, while candidate antimalarials included the imidazolopiperazine GNF179, a close analogue of KAF156, and the Plasmodium phosphatidylinositol-4-OH kinase (PI4K)-specific inhibitor KDU691. RESULTS We report a high frequency (3%-15%) of P. malariae infections with a significant reduction in ex vivo susceptibility to chloroquine, lumefantrine and artemether, which are the current frontline drugs against P. malariae infections. Unlike these compounds, potent inhibition of P. malariae and P. falciparum was observed with piperaquine exposure. Furthermore, we evaluated advanced lead antimalarial compounds. In this regard, we identified strong inhibition of P. malariae using GNF179, a close analogue of KAF156 imidazolopiperazines, which is a novel class of antimalarial drug currently in clinical Phase IIb testing. Finally, in addition to GNF179, we demonstrated that the Plasmodium PI4K-specific inhibitor KDU691 is highly inhibitory against P. malariae and P. falciparum. CONCLUSIONS Our data indicated that chloroquine, lumefantrine and artemether may not be suitable for the treatment of P. malariae infections and the potential of piperaquine, as well as new antimalarials imidazolopiperazines and PI4K-specific inhibitor, for P. malariae cure.
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Affiliation(s)
- Laurent Dembele
- Malaria Research and Training Centre (MRTC), Faculty of Pharmacy, Université des Sciences, des Techniques et des Technologies de Bamako (USTTB); Point G, P.O. Box: 1805, Bamako, Mali
| | - Yaw Aniweh
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), Volta Road, Legon, Accra, Ghana.,Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
| | - Nouhoum Diallo
- Malaria Research and Training Centre (MRTC), Faculty of Pharmacy, Université des Sciences, des Techniques et des Technologies de Bamako (USTTB); Point G, P.O. Box: 1805, Bamako, Mali
| | - Fanta Sogore
- Malaria Research and Training Centre (MRTC), Faculty of Pharmacy, Université des Sciences, des Techniques et des Technologies de Bamako (USTTB); Point G, P.O. Box: 1805, Bamako, Mali
| | - Cheick Papa Oumar Sangare
- Malaria Research and Training Centre (MRTC), Faculty of Pharmacy, Université des Sciences, des Techniques et des Technologies de Bamako (USTTB); Point G, P.O. Box: 1805, Bamako, Mali
| | - Aboubecrin Sedhigh Haidara
- Malaria Research and Training Centre (MRTC), Faculty of Pharmacy, Université des Sciences, des Techniques et des Technologies de Bamako (USTTB); Point G, P.O. Box: 1805, Bamako, Mali
| | - Aliou Traore
- Malaria Research and Training Centre (MRTC), Faculty of Pharmacy, Université des Sciences, des Techniques et des Technologies de Bamako (USTTB); Point G, P.O. Box: 1805, Bamako, Mali
| | - Seidina A S Diakité
- Malaria Research and Training Centre (MRTC), Faculty of Pharmacy, Université des Sciences, des Techniques et des Technologies de Bamako (USTTB); Point G, P.O. Box: 1805, Bamako, Mali.,West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), Volta Road, Legon, Accra, Ghana
| | - Mahamadou Diakite
- Malaria Research and Training Centre (MRTC), Faculty of Pharmacy, Université des Sciences, des Techniques et des Technologies de Bamako (USTTB); Point G, P.O. Box: 1805, Bamako, Mali
| | - Brice Campo
- Medicines for Malaria Venture (MMV) ICC Building Entrance G, 3rd floor Route de Pré-Bois 20 Post Box 1826 CH-1215, Geneva 15, Switzerland
| | - Gordon A Awandare
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), Volta Road, Legon, Accra, Ghana.,Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana
| | - Abdoulaye A Djimde
- Malaria Research and Training Centre (MRTC), Faculty of Pharmacy, Université des Sciences, des Techniques et des Technologies de Bamako (USTTB); Point G, P.O. Box: 1805, Bamako, Mali
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8
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Li YP, Mikrani R, Hu YF, Faran Ashraf Baig MM, Abbas M, Akhtar F, Xu M. Research progress of phosphatidylinositol 4-kinase and its inhibitors in inflammatory diseases. Eur J Pharmacol 2021; 907:174300. [PMID: 34217706 DOI: 10.1016/j.ejphar.2021.174300] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 06/24/2021] [Accepted: 06/30/2021] [Indexed: 01/08/2023]
Abstract
Phosphatidylinositol 4-kinase (PI4K) is a lipid kinase that can catalyze the transfer of phosphate group from ATP to the inositol ring of phosphatidylinositol (PtdIns) resulting in the phosphorylation of PtdIns at 4-OH sites, to generate phosphatidylinositol 4-phosphate (PI4P). Studies on biological functions reveal that PI4K is closely related to the occurrence and development of various inflammatory diseases such as obesity, cancer, viral infections, malaria, Alzheimer's disease, etc. PI4K-related inhibitors have been found to have the effects of inhibiting virus replication, anti-cancer, treating malaria and reducing rejection in organ transplants, among which MMV390048, an anti-malaria drug, has entered phase II clinical trial. This review discusses the classification, structure, distribution and related inhibitors of PI4K and their role in the progression of cancer, viral replication, and other inflammation induced diseases to explore their potential as therapeutic targets.
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Affiliation(s)
- Yan-Ping Li
- Department of Clinical Pharmacy, School of Preclinical Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 210009, China
| | - Reyaj Mikrani
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria 3052, Australia
| | - Yi-Fan Hu
- Department of Clinical Pharmacy, School of Preclinical Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 210009, China
| | - Mirza Muhammad Faran Ashraf Baig
- Laboratory of Biomedical Engineering for Novel Bio-functional and Pharmaceutical Nano-materials, Prince Philip Dental Hospital, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, 999077, China
| | - Muhammad Abbas
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, 210023, PR China
| | - Fahad Akhtar
- State Key Laboratory of Molecular Development Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China; School of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ming Xu
- Department of Clinical Pharmacy, School of Preclinical Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 210009, China.
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9
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Madhav H, Hoda N. An insight into the recent development of the clinical candidates for the treatment of malaria and their target proteins. Eur J Med Chem 2020; 210:112955. [PMID: 33131885 DOI: 10.1016/j.ejmech.2020.112955] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 10/08/2020] [Accepted: 10/19/2020] [Indexed: 01/18/2023]
Abstract
Malaria is an endemic disease, prevalent in tropical and subtropical regions which cost half of million deaths annually. The eradication of malaria is one of the global health priority nevertheless, current therapeutic efforts seem to be insufficient due to the emergence of drug resistance towards most of the available drugs, even first-line treatment ACT, unavailability of the vaccine, and lack of drugs with a new mechanism of action. Intensification of antimalarial research in recent years has resulted into the development of single dose multistage therapeutic agents which has advantage of overcoming the antimalarial drug resistance. The present review explored the current progress in the development of new promising antimalarials against prominent target proteins that have the potential to be a clinical candidate. Here, we also reviewed different aspects of drug resistance and highlighted new drug candidates that are currently in a clinical trial or clinical development, along with a few other molecules with excellent antimalarial activity overs ACTs. The summarized scientific value of previous approaches and structural features of antimalarials related to the activity are highlighted that will be helpful for the development of next-generation antimalarials.
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Affiliation(s)
- Hari Madhav
- Drug Design and Synthesis Laboratory, Department of Chemistry, Jamia Millia Islamia (A Central University), New Delhi, 110025, India.
| | - Nasimul Hoda
- Drug Design and Synthesis Laboratory, Department of Chemistry, Jamia Millia Islamia (A Central University), New Delhi, 110025, India.
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10
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Abstract
Antimicrobial treatment failure threatens our ability to control infections. In addition to antimicrobial resistance, treatment failures are increasingly understood to derive from cells that survive drug treatment without selection of genetically heritable mutations. Parasitic protozoa, such as Plasmodium species that cause malaria, Toxoplasma gondii and kinetoplastid protozoa, including Trypanosoma cruzi and Leishmania spp., cause millions of deaths globally. These organisms can evolve drug resistance and they also exhibit phenotypic diversity, including the formation of quiescent or dormant forms that contribute to the establishment of long-term infections that are refractory to drug treatment, which we refer to as 'persister-like cells'. In this Review, we discuss protozoan persister-like cells that have been linked to persistent infections and discuss their impact on therapeutic outcomes following drug treatment.
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Affiliation(s)
- Michael P Barrett
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK.
| | - Dennis E Kyle
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, MO, USA
| | - Joshua B Radke
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, MO, USA
| | - Rick L Tarleton
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
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11
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Penzo M, de Las Heras-Dueña L, Mata-Cantero L, Diaz-Hernandez B, Vazquez-Muñiz MJ, Ghidelli-Disse S, Drewes G, Fernandez-Alvaro E, Baker DA. High-throughput screening of the Plasmodium falciparum cGMP-dependent protein kinase identified a thiazole scaffold which kills erythrocytic and sexual stage parasites. Sci Rep 2019; 9:7005. [PMID: 31065005 PMCID: PMC6504873 DOI: 10.1038/s41598-019-42801-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 04/09/2019] [Indexed: 11/09/2022] Open
Abstract
Antimalarial drug resistance compels the quest for new compounds that target alternative pathways to current drugs. The Plasmodium cyclic GMP-dependent protein kinase (PKG) has essential functions in all of the major life cycle developmental stages. An imidazopyridine PKG inhibitor scaffold was previously shown to clear P. falciparum infection in a rodent model in vivo and blocked transmission to mosquitoes providing proof of concept for this target. To find new classes of PKG inhibitors to serve as alternative chemical starting points, we performed a high-throughput screen of the GSK Full Diversity Collection using recombinant P. falciparum PKG. We developed a robust enzymatic assay in a 1536-well plate format. Promising compounds were then tested for activity against P. falciparum asexual blood stage growth, selectivity and cytotoxicity. By using a scoring system we selected the 66 most promising PKG inhibitors (comprising nine clusters and seven singletons). Among these, thiazoles were the most potent scaffold with mid-nanomolar activity on P. falciparum blood stage and gamete development. Using Kinobeads profiling we identified additional P. falciparum protein kinases targeted by the thiazoles that mediate a faster speed of the kill than PKG-selective compounds. This scaffold represents a promising starting point to develop a new antimalarial.
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Affiliation(s)
- Maria Penzo
- GSK Global Health, Severo Ochoa 2, Tres Cantos 28760 Madrid, Spain
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, United Kingdom
| | | | | | | | | | - Sonja Ghidelli-Disse
- Cellzome GmbH, a GlaxoSmithKline Company, Meyerhofstrasse 1, 69117, Heidelberg, Germany
| | - Gerard Drewes
- Cellzome GmbH, a GlaxoSmithKline Company, Meyerhofstrasse 1, 69117, Heidelberg, Germany
| | | | - David A Baker
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, United Kingdom.
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12
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Agnello S, Brand M, Chellat MF, Gazzola S, Riedl R. A Structural View on Medicinal Chemistry Strategies against Drug Resistance. Angew Chem Int Ed Engl 2019; 58:3300-3345. [PMID: 29846032 DOI: 10.1002/anie.201802416] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 04/24/2018] [Indexed: 12/31/2022]
Abstract
The natural phenomenon of drug resistance is a widespread issue that hampers the performance of drugs in many major clinical indications. Antibacterial and antifungal drugs are affected, as well as compounds for the treatment of cancer, viral infections, or parasitic diseases. Despite the very diverse set of biological targets and organisms involved in the development of drug resistance, the underlying molecular mechanisms have been identified to understand the emergence of resistance and to overcome this detrimental process. Detailed structural information on the root causes for drug resistance is nowadays frequently available, so next-generation drugs can be designed that are anticipated to suffer less from resistance. This knowledge-based approach is essential for fighting the inevitable occurrence of drug resistance.
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Affiliation(s)
- Stefano Agnello
- Institute of Chemistry and Biotechnology, Center for Organic and Medicinal Chemistry, Zurich University of Applied Sciences (ZHAW), Einsiedlerstrasse 31, 8820, Wädenswil, Switzerland
| | - Michael Brand
- Institute of Chemistry and Biotechnology, Center for Organic and Medicinal Chemistry, Zurich University of Applied Sciences (ZHAW), Einsiedlerstrasse 31, 8820, Wädenswil, Switzerland
| | - Mathieu F Chellat
- Institute of Chemistry and Biotechnology, Center for Organic and Medicinal Chemistry, Zurich University of Applied Sciences (ZHAW), Einsiedlerstrasse 31, 8820, Wädenswil, Switzerland
| | - Silvia Gazzola
- Institute of Chemistry and Biotechnology, Center for Organic and Medicinal Chemistry, Zurich University of Applied Sciences (ZHAW), Einsiedlerstrasse 31, 8820, Wädenswil, Switzerland
| | - Rainer Riedl
- Institute of Chemistry and Biotechnology, Center for Organic and Medicinal Chemistry, Zurich University of Applied Sciences (ZHAW), Einsiedlerstrasse 31, 8820, Wädenswil, Switzerland
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13
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Agnello S, Brand M, Chellat MF, Gazzola S, Riedl R. Eine strukturelle Evaluierung medizinalchemischer Strategien gegen Wirkstoffresistenzen. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201802416] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Stefano Agnello
- Institut für Chemie und Biotechnologie; FS Organische Chemie und Medizinalchemie; Zürcher Hochschule für Angewandte Wissenschaften (ZHAW); Einsiedlerstrasse 31 CH-8820 Wädenswil Schweiz
| | - Michael Brand
- Institut für Chemie und Biotechnologie; FS Organische Chemie und Medizinalchemie; Zürcher Hochschule für Angewandte Wissenschaften (ZHAW); Einsiedlerstrasse 31 CH-8820 Wädenswil Schweiz
| | - Mathieu F. Chellat
- Institut für Chemie und Biotechnologie; FS Organische Chemie und Medizinalchemie; Zürcher Hochschule für Angewandte Wissenschaften (ZHAW); Einsiedlerstrasse 31 CH-8820 Wädenswil Schweiz
| | - Silvia Gazzola
- Institut für Chemie und Biotechnologie; FS Organische Chemie und Medizinalchemie; Zürcher Hochschule für Angewandte Wissenschaften (ZHAW); Einsiedlerstrasse 31 CH-8820 Wädenswil Schweiz
| | - Rainer Riedl
- Institut für Chemie und Biotechnologie; FS Organische Chemie und Medizinalchemie; Zürcher Hochschule für Angewandte Wissenschaften (ZHAW); Einsiedlerstrasse 31 CH-8820 Wädenswil Schweiz
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14
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Abstract
Toxoplasma gondii is a common zoonotic infection of humans, and estimates indicate that 1-2 billion people are chronically infected. Although largely asymptomatic, chronic infection poses risk of serious disease due to reactivation should immunity decline. Current therapies for toxoplasmosis only control acute infection caused by actively proliferating tachyzoites but do not eradicate the chronic tissue cyst stages. As well, there are considerable adverse side effects of the most commonly used therapy of combined sulfadiazine and pyrimethamine. Targeting the folate pathway is also an effective treatment for malaria, caused by the related parasites Plasmodium spp., suggesting common agents might be used to treat both infections. Here, we evaluated currently approved and newly emerging medicines for malaria to determine if such compounds might also prove useful for treating toxoplasmosis. Surprisingly, the majority of antimalarial compounds being used currently or in development for treatment of malaria were only modestly effective at inhibiting in vitro growth of T. gondii tachyzoites. These findings suggest that many essential processes in P. falciparum that are targeted by antimalarial compounds are either divergent or nonessential in T. gondii, thus limiting options for repurposing of current antimalarial medicines for toxoplasmosis.
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Affiliation(s)
- Joshua B. Radke
- Department of Molecular Microbiology, Washington University Sch. Med., 600 S. Euclid Ave., St Louis, MO 63110
| | - Jeremy N. Burrows
- Medicines for Malaria Venture, ICC, Route de Pré3Bois 20, 1215 Geneva, Switzerland
| | - Daniel E. Goldberg
- Departments of Medicine and Molecular Microbiology, Washington University Sch. Med., 660 S. Euclid Ave., St Louis, MO 63110
| | - L. David Sibley
- Department of Molecular Microbiology, Washington University Sch. Med., 600 S. Euclid Ave., St Louis, MO 63110
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15
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Abstract
Phosphatidylinositol (PI) kinases (PIKs) regulate cell proliferation, survival, membrane trafficking, and other processes. PIK classes are distinguished by substrate preference and their distinct phosphorylated PI products. Recently two Plasmodium falciparum PIKs (PfPIKs) have been recognized as attractive new drug targets. Here we briefly summarize PIK biochemistry and recent progress with PfPIKs.
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Affiliation(s)
- Matthew R Hassett
- Department of Chemistry and Department of Biochemistry & Cellular & Molecular Biology, Georgetown University, 37th and O Streets NW, Washington DC 20057, USA
| | - Paul D Roepe
- Department of Chemistry and Department of Biochemistry & Cellular & Molecular Biology, Georgetown University, 37th and O Streets NW, Washington DC 20057, USA.
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16
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Dembele L, Gupta DK, Lim MY, Ang X, Selva JJ, Chotivanich K, Nguon C, Dondorp AM, Bonamy GMC, Diagana TT, Bifani P. Imidazolopiperazines Kill both Rings and Dormant Rings in Wild-Type and K13 Artemisinin-Resistant Plasmodium falciparum In Vitro. Antimicrob Agents Chemother 2018; 62:e02235-17. [PMID: 29530849 DOI: 10.1128/AAC.02235-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Artemisinin (ART) resistance has spread through Southeast Asia, posing a serious threat to the control and elimination of malaria. ART resistance has been associated with mutations in the Plasmodium falciparum kelch-13 (Pfk13) propeller domain. Phenotypically, ART resistance is defined as delayed parasite clearance in patients due to the reduced susceptibility of early ring-stage parasites to the active metabolite of ART dihydroartemisinin (DHA). Early rings can enter a state of quiescence upon DHA exposure and resume growth in its absence. These quiescent rings are referred to as dormant rings or DHA-pretreated rings (here called dormant rings). The imidazolopiperazines (IPZ) are a novel class of antimalarial drugs that have demonstrated efficacy in early clinical trials. Here, we characterized the stage of action of the IPZ GNF179 and evaluated its activity against rings and dormant rings in wild-type and ART-resistant parasites. Unlike DHA, GNF179 does not induce dormancy. We show that GNF179 is more rapidly cidal against schizonts than against ring and trophozoite stages. However, with 12 h of exposure, the compound effectively kills rings and dormant rings of both susceptible and ART-resistant parasites within 72 h. We further demonstrate that in combination with ART, GNF179 effectively prevents recrudescence of dormant rings, including those bearing pfk13 propeller mutations.
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17
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Subramaniam S, Schmid CD, Guan XL, Mäser P. Using Yeast Synthetic Lethality To Inform Drug Combination for Malaria. Antimicrob Agents Chemother 2018; 62:e01533-17. [PMID: 29358287 DOI: 10.1128/AAC.01533-17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 12/30/2017] [Indexed: 11/28/2022] Open
Abstract
Combinatorial chemotherapy is necessary for the treatment of malaria. However, finding a suitable partner drug for a new candidate is challenging. Here we develop an algorithm that identifies all of the gene pairs of Plasmodium falciparum that possess orthologues in yeast that have a synthetic lethal interaction but are absent in humans. This suggests new options for drug combinations, particularly for inhibitors of targets such as P. falciparum calcineurin, cation ATPase 4, or phosphatidylinositol 4-kinase.
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18
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Abstract
A curious aspect of the evolution of the hypnozoite theory of malarial relapse is its transmogrification from theory into 'fact', this being of historical, linguistic, scientific and sociological interest. As far as it goes, the hypnozoite explanation for relapse is almost certainly correct. I contend, however, that many of the genotypically homologous, non-reinfection, relapse-like Plasmodium vivax recurrences that researchers ascribe to hypnozoite activation are probably hypnozoite-independent. Indeed, some malariologists are starting to recognize that homologous P. vivax recurrences have most likely been overattributed to activation of hypnozoites. Hitherto identified, non-hypnozoite, possible plasmodial sources of recurrence that must be considered, besides circulating erythrocytic stages, include parasites in splenic dendritic cells, other cells in the spleen (in addition to infected erythrocytes there), bone marrow (importantly) and the skin. I argue that we need to take into account the possibility of a dual or multiple extra-vascular origin of P. vivax non-reinfection recurrences, not arbitrarily discount it. The existence of a P. vivax reservoir(s) is a topical subject and one of practical importance for malaria eradication. Pertinent drug-associated matters are also discussed, as is the dormancy-related significance of clues provided by blood-stage-induced malarial infection.
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19
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Abstract
A marked decrease in malaria-related deaths worldwide has been attributed to the administration of effective antimalarials against Plasmodium falciparum, in particular, artemisinin-based combination therapies (ACTs). Increasingly, ACTs are also used to treat Plasmodium vivax, the second major human malaria parasite. However, resistance to frontline artemisinins and partner drugs is now causing the failure of P. falciparum ACTs in southeast Asia. In this Review, we discuss our current knowledge of markers and mechanisms of resistance to artemisinins and ACTs. In particular, we describe the identification of mutations in the propeller domains of Kelch 13 as the primary marker for artemisinin resistance in P. falciparum and explore two major mechanisms of resistance that have been independently proposed: the activation of the unfolded protein response and proteostatic dysregulation of parasite phosphatidylinositol 3- kinase. We emphasize the continuing challenges and the imminent need to understand mechanisms of resistance to improve parasite detection strategies, develop new combinations to eliminate resistant parasites and prevent their global spread.
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