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Si W, Fang C, Liu C, Yin M, Xu W, Li Y, Yan X, Shen Y, Cao J, Sun J. Why is Babesia not killed by artemisinin like Plasmodium? Parasit Vectors 2023; 16:193. [PMID: 37291657 DOI: 10.1186/s13071-023-05783-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 04/21/2023] [Indexed: 06/10/2023] Open
Abstract
Babesia spp. are intraerythrocytic apicomplexans that digest and utilize red blood cells in a similar way to intraerythrocytic Plasmodium spp., but unlike the latter, are not sensitive to artemisinin. A comparison of Babesia and Plasmodium genomes revealed that Babesia genomes, which are smaller than those of Plasmodium, lack numerous genes, and especially haem synthesis-related genes, that are found in the latter. Single-cell sequencing analysis showed that the different treatment groups of Babesia microti with expressed pentose phosphate pathway-related, DNA replication-related, antioxidation-related, glycolysis-related, and glutathione-related genes were not as sensitive to artemether as Plasmodium yoelii 17XNL. In particular, pentose phosphate pathway-related, DNA replication-related, and glutathione-related genes, which were actively expressed in P. yoelii 17XNL, were not actively expressed in B. microti. Supplying iron in vivo can promote the reproduction of B. microti. These results suggest that Babesia spp. lack a similar mechanism to that of malaria parasites through which the haem or iron in hemoglobin is utilized, and that this likely leads to their insensitivity to artemisinin.
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Affiliation(s)
- Wenwen Si
- Institute for Infectious Diseases and Vaccine Development, School of Medicine, Tongji University, Shanghai, People's Republic of China
| | - Chuantao Fang
- Institute for Infectious Diseases and Vaccine Development, School of Medicine, Tongji University, Shanghai, People's Republic of China
- Shanghai Tenth People's Hospital, Tenth peoples hospital of Tongji university, Shanghai, People's Republic of China
| | - Chuang Liu
- Institute for Infectious Diseases and Vaccine Development, School of Medicine, Tongji University, Shanghai, People's Republic of China
| | - Meng Yin
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), Shanghai, People's Republic of China
| | - Wenyue Xu
- Department of Pathogenic Biology, Army Medical University (Third Military Medical University), Chongqing, People's Republic of China
| | - Yanna Li
- Institute for Infectious Diseases and Vaccine Development, School of Medicine, Tongji University, Shanghai, People's Republic of China
| | - Xiaoli Yan
- Institute for Infectious Diseases and Vaccine Development, School of Medicine, Tongji University, Shanghai, People's Republic of China
| | - Yujuan Shen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), Shanghai, People's Republic of China
| | - Jianping Cao
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), Shanghai, People's Republic of China
| | - Jun Sun
- Institute for Infectious Diseases and Vaccine Development, School of Medicine, Tongji University, Shanghai, People's Republic of China.
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Kampoun T, Koonyosying P, Ruangsuriya J, Prommana P, Shaw PJ, Kamchonwongpaisan S, Suwito H, Puspaningsih NNT, Uthaipibull C, Srichairatanakool S. Antagonistic antimalarial properties of a methoxyamino chalcone derivative and 3-hydroxypyridinones in combination with dihydroartemisinin against Plasmodium falciparum. PeerJ 2023; 11:e15187. [PMID: 37131988 PMCID: PMC10149052 DOI: 10.7717/peerj.15187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 03/15/2023] [Indexed: 05/04/2023] Open
Abstract
Background The spread of artemisinin (ART)-resistant Plasmodium falciparum threatens the control of malaria. Mutations in the propeller domains of P. falciparum Kelch13 (k13) are strongly associated with ART resistance. Ferredoxin (Fd), a component of the ferredoxin/NADP+ reductase (Fd/FNR) redox system, is essential for isoprenoid precursor synthesis in the plasmodial apicoplast, which is important for K13-dependent hemoglobin trafficking and ART activation. Therefore, Fd is an antimalarial drug target and fd mutations may modulate ART sensitivity. We hypothesized that loss of Fd/FNR function enhances the effect of k13 mutation on ART resistance. Methods In this study, methoxyamino chalcone (C3), an antimalarial compound that has been reported to inhibit the interaction of recombinant Fd and FNR proteins, was used as a chemical inhibitor of the Fd/FNR redox system. We investigated the inhibitory effects of dihydroartemisinin (DHA), C3, and iron chelators including deferiprone (DFP), 1-(N-acetyl-6-aminohexyl)-3-hydroxy-2-methylpyridin-4-one (CM1) and deferiprone-resveratrol hybrid (DFP-RVT) against wild-type (WT), k13 mutant, fd mutant, and k13 fd double mutant P. falciparum parasites. Furthermore, we investigated the pharmacological interaction of C3 with DHA, in which the iron chelators were used as reference ART antagonists. Results C3 showed antimalarial potency similar to that of the iron chelators. As expected, combining DHA with C3 or iron chelators exhibited a moderately antagonistic effect. No differences were observed among the mutant parasites with respect to their sensitivity to C3, iron chelators, or the interactions of these compounds with DHA. Discussion The data suggest that inhibitors of the Fd/FNR redox system should be avoided as ART partner drugs in ART combination therapy for treating malaria.
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Affiliation(s)
- Tanyaluck Kampoun
- Department of Biochemistry, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Pimpisid Koonyosying
- Department of Biochemistry, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Jetsada Ruangsuriya
- Department of Biochemistry, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Parichat Prommana
- Medical Molecular Biotechnology Research Group, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Pathum Thani, Thailand
| | - Philip J. Shaw
- Medical Molecular Biotechnology Research Group, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Pathum Thani, Thailand
| | - Sumalee Kamchonwongpaisan
- Medical Molecular Biotechnology Research Group, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Pathum Thani, Thailand
| | - Hery Suwito
- Department of Chemistry, Faculty of Science and Technology, Airlangga University, Surabaya, Indonesia
| | - Ni Nyoman Tri Puspaningsih
- Laboratory of Proteomics, University-CoE Research Center for Bio-Molecule Engineering, Universitas Airlangga, Surabaya, Indonesia
| | - Chairat Uthaipibull
- Medical Molecular Biotechnology Research Group, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Pathum Thani, Thailand
- Thailand Center of Excellence for Life Sciences (TCELS), Bangkok, Thailand
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Deferiprone−Resveratrol Hybrid, an Iron-Chelating Compound, Acts as an Antimalarial and Hepatoprotective Agent in Plasmodium berghei-Infected Mice. Bioinorg Chem Appl 2022; 2022:3869337. [DOI: 10.1155/2022/3869337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 10/19/2022] [Accepted: 11/14/2022] [Indexed: 11/26/2022] Open
Abstract
Free heme in plasma acts as a prooxidant; thus, it is bound to hemopexin and eliminated by the liver. High iron content in the liver can support Plasmodium growth and cause oxidative liver injury. Inversely, the withholding of excessive iron can inhibit this growth and protect the liver against malaria infection. This study examined the effects of a deferiprone-resveratrol (DFP-RVT) hybrid on malaria parasites and its relevant hepatoprotective properties. Mice were infected with P. berghei, gavage DFP-RVT, deferiprone (DFP), and pyrimethamine (PYR) for 8 consecutive days. Blood and liver parameters were then evaluated. The presence of blood-stage parasites was determined using the microscopic Giemsa staining method. Subsequently, plasma liver enzymes, heme, and concentrations of thiobarbituric acid-reactive substances (TBARS) were determined. The liver tissue was examined pathologically and heme and TBARS concentrations were then quantified. The results indicate that the suppression potency against P. berghei growth occurred as follows: PYR > DFP-RVT hybrid > DFP. Importantly, DFP-RVT significantly improved RBC size, restored alanine aminotransferase and alkaline activities, and increased heme and TBARS concentrations. The compound also reduced the liver weight index, heme, and TBARS concentrations significantly when compared to mice that were untreated. Our findings support the contention that the hepatoprotective effect of DFP-RVT is associated with parasite burden, iron depletion, and lipid peroxidation in the host.
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Sloan MA, Aghabi D, Harding CR. Orchestrating a heist: uptake and storage of metals by apicomplexan parasites. MICROBIOLOGY (READING, ENGLAND) 2021; 167. [PMID: 34898419 PMCID: PMC7612242 DOI: 10.1099/mic.0.001114] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Megan A Sloan
- Wellcome Centre for Integrative Parasitology, Institute for Infection, Immunity and Inflammation, University of Glasgow, UK
| | - Dana Aghabi
- Wellcome Centre for Integrative Parasitology, Institute for Infection, Immunity and Inflammation, University of Glasgow, UK
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Ribeiro M, Sousa CA, Simões M. Harnessing microbial iron chelators to develop innovative therapeutic agents. J Adv Res 2021; 39:89-101. [PMID: 35777919 PMCID: PMC9263657 DOI: 10.1016/j.jare.2021.10.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 10/24/2021] [Accepted: 10/27/2021] [Indexed: 01/19/2023] Open
Abstract
Microbial iron chelators as a new route to develop inspiring antimicrobials. Siderophore-mimicking antibiotics as a pathogen-targeted strategy. Effectiveness of iron chelators on antibiotic-resistant Gram-negative bacteria. Iron chelators and the treatment of iron overload diseases. Iron chelators as powerful tools for cancer therapy.
Background Aim of Review Key Scientific Concepts of Review
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Anti-Malarial and Anti-Lipid Peroxidation Activities of Deferiprone-Resveratrol Hybrid in Plasmodium berghei-Infected Mice. BIOLOGY 2021; 10:biology10090911. [PMID: 34571788 PMCID: PMC8468766 DOI: 10.3390/biology10090911] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 09/07/2021] [Accepted: 09/09/2021] [Indexed: 11/30/2022]
Abstract
Simple Summary Malaria remains a public health problem in tropical and subtropical countries. The emergence of malaria parasite resistance to antimalarial drugs has been recently considered a serious issue. Alternative compounds have become an important therapeutic strategy to achieve malaria treatment. Iron chelators are widely used for the treatment of iron overload patients. The iron chelators also reveal an inhibitory effect on malaria parasite growth by depriving the parasite intracellular iron. This study presented the potential of the novel hybrid iron chelator, deferiprone-resveratrol hybrid on the inhibition of malaria parasite growth, the improvement of hematological parameters and the alleviatation of oxidative tissue damage in malaria-infected mice. Deferiprone-resveratrol hybrid would be used as a therapeutic/preventive compound to increase the efficacy of treatment and eliminate an antimalarial drug resistance. Abstract Iron is essential for all organisms including fast-dividing malarial parasites. Inversely, iron chelators can inhibit parasite growth through the inhibition of DNA synthesis and can ameliorate oxidative cell damage. Deferiprone (DFP)-resveratrol (RVT) hybrid (DFP-RVT) is a lipophilic anti-oxidative, iron-chelating agent that has displayed potent neuroprotective and anti-plasmodium activities in vitro. The goal of this work was to investigate the inhibitory effects of DFP-RVT on parasite growth and oxidative stress levels during malaria infections. Mice were intraperitoneally infected with P. berghei and orally administered with DFP, DFP-RVT and pyrimethamine for 4 d. The percentage of parasitemia was determined using Giemsa’s staining/microscopic examination. Amounts of the lipid-peroxidation product, thiobarbituric acid-reactive substance (TBARS), were determined in both plasma and liver tissue. In our findings, DFP-RVT exhibited a greater potent inhibitory effect and revealed an improvement in anemia and liver damage in infected mice than DFP. To this point, the anti-malarial activity was found to be associated with anti-RBC hemolysis and the liver weight index. In addition, plasma and liver TBARS levels in the DFP-RVT-treated mice were lower than those in DFP-treated mice. Thus, DFP-RVT could exert anti-plasmodium, anti-hemolysis and anti-lipid peroxidation activities to a better degree than DFP in P. berghei-infected mice.
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Identifying a Deferiprone-Resveratrol Hybrid as an Effective Lipophilic Anti-Plasmodial Agent. Molecules 2021; 26:molecules26134074. [PMID: 34279413 PMCID: PMC8271877 DOI: 10.3390/molecules26134074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 06/27/2021] [Accepted: 07/01/2021] [Indexed: 11/17/2022] Open
Abstract
Malaria i a serious health problem caused by Plasmodium spp. that can be treated by an anti-folate pyrimethamine (PYR) drug. Deferiprone (DFP) is an oral iron chelator used for the treatment of iron overload and has been recognized for its potential anti-malarial activity. Deferiprone-resveratrol hybrids (DFP-RVT) have been synthesized to present therapeutic efficacy at a level which is superior to DFP. We have focused on determining the lipophilicity, toxicity and inhibitory effects on P. falciparum growth and the iron-chelating activity of labile iron pools (LIPs) by DFP-RVT. According to our findings, DFP-RVT was more lipophilic than DFP (p < 0.05) and nontoxic to blood mononuclear cells. Potency for the inhibition of P. falciparum was PYR > DFP-RVT > DFP in the 3D7 strain (IC50 = 0.05, 16.82 and 47.67 µM, respectively) and DFP-RVT > DFP > PYR in the K1 strain (IC50 = 13.38, 42.02 and 105.61 µM, respectively). The combined treatment of DFP-RVT with PYR additionally enhanced the PYR activity in both strains. DFP-RVT dose-dependently lowered LIP levels in PRBCs and was observed to be more effective than DFP at equal concentrations. Thus, the DFP-RVT hybrid should be considered a candidate as an adjuvant anti-malarial drug through the deprivation of cellular iron.
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Maya-Maldonado K, Cardoso-Jaime V, González-Olvera G, Osorio B, Recio-Tótoro B, Manrique-Saide P, Rodríguez-Sánchez IP, Lanz-Mendoza H, Missirlis F, Hernández-Hernández FDLC. Mosquito metallomics reveal copper and iron as critical factors for Plasmodium infection. PLoS Negl Trop Dis 2021; 15:e0009509. [PMID: 34161336 PMCID: PMC8221525 DOI: 10.1371/journal.pntd.0009509] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 05/26/2021] [Indexed: 11/18/2022] Open
Abstract
Iron and copper chelation restricts Plasmodium growth in vitro and in mammalian hosts. The parasite alters metal homeostasis in red blood cells to its favor, for example metabolizing hemoglobin to hemozoin. Metal interactions with the mosquito have not, however, been studied. Here, we describe the metallomes of Anopheles albimanus and Aedes aegypti throughout their life cycle and following a blood meal. Consistent with previous reports, we found evidence of maternal iron deposition in embryos of Ae. aegypti, but less so in An. albimanus. Sodium, potassium, iron, and copper are present at higher concentrations during larval developmental stages. Two An. albimanus phenotypes that differ in their susceptibility to Plasmodium berghei infection were studied. The susceptible white stripe (ws) phenotype was named after a dorsal white stripe apparent during larval stages 3, 4, and pupae. During larval stage 3, ws larvae accumulate more iron and copper than the resistant brown stripe (bs) phenotype counterparts. A similar increase in copper and iron accumulation was also observed in the susceptible ws, but not in the resistant bs phenotype following P. berghei infection. Feeding ws mosquitoes with extracellular iron and copper chelators before and after receiving Plasmodium-infected blood protected from infection and simultaneously affected follicular development in the case of iron chelation. Unexpectedly, the application of the iron chelator to the bs strain reverted resistance to infection. Besides a drop in iron, iron-chelated bs mosquitoes experienced a concomitant loss of copper. Thus, the effect of metal chelation on P. berghei infectivity was strain-specific.
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Affiliation(s)
- Krystal Maya-Maldonado
- Departamento de Infectómica y Patogénesis Molecular, Cinvestav, Ciudad de México, México
- Centro de Investigaciones sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México
| | - Victor Cardoso-Jaime
- Departamento de Infectómica y Patogénesis Molecular, Cinvestav, Ciudad de México, México
- Centro de Investigaciones sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México
| | - Gabriela González-Olvera
- Unidad Colaborativa para Bioensayos Entomológicos, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, México
| | - Beatriz Osorio
- Departamento de Fisiología, Biofísica y Neurociencias, Cinvestav, Ciudad de México, México
| | - Benito Recio-Tótoro
- Centro de Investigaciones sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Pablo Manrique-Saide
- Unidad Colaborativa para Bioensayos Entomológicos, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, México
| | - Iram Pablo Rodríguez-Sánchez
- Laboratorio de Fisiología Molecular y Estructural, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, México
| | - Humberto Lanz-Mendoza
- Centro de Investigaciones sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México
| | - Fanis Missirlis
- Departamento de Fisiología, Biofísica y Neurociencias, Cinvestav, Ciudad de México, México
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Saraiva RG, Dimopoulos G. Bacterial natural products in the fight against mosquito-transmitted tropical diseases. Nat Prod Rep 2021; 37:338-354. [PMID: 31544193 DOI: 10.1039/c9np00042a] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Covering: up to 2019 Secondary metabolites of microbial origin have long been acknowledged as medically relevant, but their full potential remains largely unexploited. Of the countless natural compounds discovered thus far, only 5-10% have been isolated from microorganisms. At the same time, while whole-genome sequencing has demonstrated that bacteria and fungi often encode natural products, only a few genera have yet been mined for new compounds. This review explores the contributions of bacterial natural products to combatting infection by malaria parasites, filarial worms, and arboviruses such as dengue, Zika, Chikungunya, and West Nile. It highlights how molecules isolated from microorganisms ranging from marine cyanobacteria to mosquito endosymbionts can be exploited as antimicrobials and antivirals. Pursuit of this mostly untapped source of chemical entities will potentially result in new interventions against these tropical diseases, which are urgently needed to combat the increase in the incidence of resistance.
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Affiliation(s)
- Raúl G Saraiva
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA.
| | - George Dimopoulos
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA.
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Fang Q, Maglangit F, Wu L, Ebel R, Kyeremeh K, Andersen JH, Annang F, Pérez-Moreno G, Reyes F, Deng H. Signalling and Bioactive Metabolites from Streptomyces sp. RK44. Molecules 2020; 25:E460. [PMID: 31979050 PMCID: PMC7037778 DOI: 10.3390/molecules25030460] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 01/17/2020] [Accepted: 01/21/2020] [Indexed: 02/07/2023] Open
Abstract
Streptomyces remains one of the prolific sources of structural diversity, and a reservoir to mine for novel natural products. Continued screening for new Streptomyces strains in our laboratory led to the isolation of Streptomyces sp. RK44 from the underexplored areas of Kintampo waterfalls, Ghana, Africa. Preliminary screening of the metabolites from this strain resulted in the characterization of a new 2-alkyl-4-hydroxymethylfuran carboxamide (AHFA) 1 together with five known compounds, cyclo-(L-Pro-Gly) 2, cyclo-(L-Pro-L-Phe) 3, cyclo-(L-Pro-L-Val) 4, cyclo-(L-Leu-Hyp) 5, and deferoxamine E 6. AHFA 1, a methylenomycin (MMF) homolog, exhibited anti-proliferative activity (EC50 = 89.6 µM) against melanoma A2058 cell lines. This activity, albeit weak is the first report amongst MMFs. Furthermore, the putative biosynthetic gene cluster (ahfa) was identified for the biosynthesis of AHFA 1. DFO-E 6 displayed potent anti-plasmodial activity (IC50 = 1.08µM) against P. falciparum 3D7. High-resolution electrospray ionization mass spectrometry (HR ESIMS) and molecular network assisted the targeted-isolation process, and tentatively identified six AHFA analogues, 7-12 and six siderophores 13-18.
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Affiliation(s)
- Qing Fang
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, UK; (Q.F.); (F.M.); (L.W.); (R.E.)
| | - Fleurdeliz Maglangit
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, UK; (Q.F.); (F.M.); (L.W.); (R.E.)
- College of Science, Department of Biology and Environmental Science, University of the Philippines Cebu, Lahug, Cebu 6000, Philippines
| | - Linrui Wu
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, UK; (Q.F.); (F.M.); (L.W.); (R.E.)
| | - Rainer Ebel
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, UK; (Q.F.); (F.M.); (L.W.); (R.E.)
| | - Kwaku Kyeremeh
- Marine and Plant Research Laboratory of Ghana, Department of Chemistry, University of Ghana, P.O. Box LG56 Legon, Accra, Ghana;
| | | | - Frederick Annang
- Fundación MEDINA, Avda. del Conocimiento 34, 18016 Armilla, Granada, Spain; (F.A.); (F.R.)
| | - Guiomar Pérez-Moreno
- Instituto de Parasitología y Biomedicina “López-Neyra”, Consejo Superior de Investigaciones Científicas (CSIC) Avda. del Conocimiento 17, 18016 Armilla, Granada, Spain;
| | - Fernando Reyes
- Fundación MEDINA, Avda. del Conocimiento 34, 18016 Armilla, Granada, Spain; (F.A.); (F.R.)
| | - Hai Deng
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, UK; (Q.F.); (F.M.); (L.W.); (R.E.)
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Kariuki CK, Stijlemans B, Magez S. The Trypanosomal Transferrin Receptor of Trypanosoma Brucei-A Review. Trop Med Infect Dis 2019; 4:tropicalmed4040126. [PMID: 31581506 PMCID: PMC6958415 DOI: 10.3390/tropicalmed4040126] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 09/19/2019] [Accepted: 09/25/2019] [Indexed: 02/06/2023] Open
Abstract
Iron is an essential element for life. Its uptake and utility requires a careful balancing with its toxic capacity, with mammals evolving a safe and bio-viable means of its transport and storage. This transport and storage is also utilized as part of the iron-sequestration arsenal employed by the mammalian hosts’ ‘nutritional immunity’ against parasites. Interestingly, a key element of iron transport, i.e., serum transferrin (Tf), is an essential growth factor for parasitic haemo-protozoans of the genus Trypanosoma. These are major mammalian parasites causing the diseases human African trypanosomosis (HAT) and animal trypanosomosis (AT). Using components of their well-characterized immune evasion system, bloodstream Trypanosoma brucei parasites adapt and scavenge for the mammalian host serum transferrin within their broad host range. The expression site associated genes (ESAG6 and 7) are utilized to construct a heterodimeric serum Tf binding complex which, within its niche in the flagellar pocket, and coupled to the trypanosomes’ fast endocytic rate, allows receptor-mediated acquisition of essential iron from their environment. This review summarizes current knowledge of the trypanosomal transferrin receptor (TfR), with emphasis on the structure and function of the receptor, both in physiological conditions as well as in conditions where the iron supply to parasites is being limited. Potential applications using current knowledge of the parasite receptor are also briefly discussed, primarily focused on potential therapeutic interventions.
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Affiliation(s)
- Christopher K. Kariuki
- Laboratory of Cellular and Molecular Interactions (CMIM), Vrije Universiteit Brussels, Brussels, 1050 Ixelles, Belgium;
- Department of Tropical and Infectious Diseases, Institute of Primate Research (IPR), 00502 Nairobi, Kenya
- Correspondence: (C.K.K.); (S.M.); Tel.: +322-629-1975 (C.K.K.); +82-32626-4207 (S.M.)
| | - Benoit Stijlemans
- Laboratory of Cellular and Molecular Interactions (CMIM), Vrije Universiteit Brussels, Brussels, 1050 Ixelles, Belgium;
- Myeloid Cell Immunology Lab, VIB Center for Inflammation Research, Brussels, 9052 Gent, Belgium
| | - Stefan Magez
- Laboratory of Cellular and Molecular Interactions (CMIM), Vrije Universiteit Brussels, Brussels, 1050 Ixelles, Belgium;
- Laboratory for Biomedical Research, Ghent University Global Campus, Yeonsu-Gu, Incheon 219220, Korea
- Correspondence: (C.K.K.); (S.M.); Tel.: +322-629-1975 (C.K.K.); +82-32626-4207 (S.M.)
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Parkinson CJ, Birrell GW, Chavchich M, Mackenzie D, Haynes RK, de Kock C, Richardson DR, Edstein MD. Development of pyridyl thiosemicarbazones as highly potent agents for the treatment of malaria after oral administration. J Antimicrob Chemother 2019; 74:2965-2973. [DOI: 10.1093/jac/dkz290] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 06/04/2019] [Accepted: 06/05/2019] [Indexed: 01/22/2023] Open
Abstract
AbstractObjectivesDrug resistance exists to all current and investigational antimalarial drug classes. Consequently, we have set out to develop chemically and mechanistically discrete antimalarials. Here we report on the development of thiosemicarbazone (TSC) antimalarials, with TSC3 as the most advanced lead.MethodsThiosemicarbazones were generated through simple condensation reactions of thiosemicarbazides and ketones. TSC3 was selected and tested for in vitro antimalarial activities against MDR Plasmodium falciparum lines using the [3H]hypoxanthine growth assay, in vitro cytotoxicity against mammalian cell lines using the alamarBlue fluorescence cell viability assay, in vivo potency in the mouse–Plasmodium berghei model and blood exposure in mice measured by LC-MS for pharmacokinetic analysis.ResultsTSC3 showed potent in vitro activity against atovaquone-, dihydroartemisinin-, chloroquine- and mefloquine-resistant P. falciparum lines (EC50 <15 nM). The selectivity index (EC50 cells/EC50Pf W2 line) of TSC3 was >500 in two of three mammalian cell lines. In P. berghei-infected mice, TSC3 showed potent activity in the Peters 4 day suppression test (ED50 1.2 mg/kg/day) and was as potent as artesunate and chloroquine in the curative modified Thompson test. A single oral dose of TSC3 at 16 mg/kg in healthy mice achieved a mean maximum blood concentration of 1883 ng/mL at 1 h after dosing and an elimination half-life of 48.7 h in groups of five mice.ConclusionsTSC3 shows promise as a persistent, potent and orally effective antimalarial. This, coupled with the extremely low cost of synthesis, suggests that the further development of antimalarial thiosemicarbazones is clearly warranted.
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Affiliation(s)
| | - Geoffrey W Birrell
- Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | - Marina Chavchich
- Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | - Donna Mackenzie
- Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | - Richard K Haynes
- Centre for Excellence in Pharmaceutical Discovery, North-West University, Potchefstroom, South Africa
| | - Carmen de Kock
- Division of Pharmacology, University of Cape Town, Observatory, South Africa
| | - Des R Richardson
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, The University of Sydney, Sydney, Australia
| | - Michael D Edstein
- Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
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13
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Akladios FN, Andrew SD, Boog SJ, de Kock C, Haynes RK, Parkinson CJ. The Evaluation of Metal Co-ordinating Bis-Thiosemicarbazones as Potential Anti-malarial Agents. Med Chem 2019; 15:51-58. [DOI: 10.2174/1573406414666180525132204] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 04/06/2018] [Accepted: 04/22/2018] [Indexed: 11/22/2022]
Abstract
Background:The emergence of resistance to the artemisinins which are the current mainstays for antimalarial chemotheraphy has created an environment where the development of new drugs acting in a mechanistally discrete manner is a priority.Objective:The goal of this work was to synthesize ane evaluate bis-thiosemicarbazones as potential antimalarial agents. </P><P> Methods: Fifteen compounds were generated using two condensation protocols and evaluated in vitro against the NF54 (CQ sensitive) strain of Plasmodium falciparum. A preliminary assessment of the potential for human toxicity was conducted in vitro against the MRC5 human lung fibroblast line.Results:The activity of the bis-thiosemicarbazones was highly dependent on the nature of the arene at the core of the structure. The inclusion of a non-coordinating benzene core resulted in inactive compounds, while the inclusion of a pyridyl core resulted in compounds of moderate or potent antimalarial activity (4 compounds showing IC50 < 250 nM).Conclusion:Bis-thiosemicarbazones containing a central pyridyl core display potent antimalarial activity in vitro. Sequestration and activation of ferric iron appears to play a significant role in this activity. Ongoing studies are aimed at further development of this series as potential antimalarials.
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Affiliation(s)
- Fady N. Akladios
- School of Biomedical Sciences, Charles Sturt University, Orange, NSW 2800, Australia
| | - Scott D. Andrew
- School of Biomedical Sciences, Charles Sturt University, Orange, NSW 2800, Australia
| | - Samantha J. Boog
- School of Biomedical Sciences, Charles Sturt University, Orange, NSW 2800, Australia
| | - Carmen de Kock
- Division of Clinical Pharmacology, University of Cape Town, Groote Schuur Hospital, Observatory 7925, South Africa
| | - Richard K. Haynes
- Centre for Excellence for Pharmaceutical Sciences, North-West University, Potchefstroom 2531, South Africa
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14
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Iron deficiency during pregnancy is associated with a reduced risk of adverse birth outcomes in a malaria-endemic area in a longitudinal cohort study. BMC Med 2018; 16:156. [PMID: 30231938 PMCID: PMC6149228 DOI: 10.1186/s12916-018-1146-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 08/03/2018] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Low birth weight (LBW) and preterm birth (PTB) are major contributors to infant mortality and chronic childhood morbidity. Understanding factors that contribute to or protect against these adverse birth outcomes is an important global health priority. Anaemia and iron deficiency are common in malaria-endemic regions, but there are concerns regarding the value of iron supplementation among pregnant women in malaria-endemic areas due to reports that iron supplementation may increase the risk of malaria. There is a lack of evidence on the impact of iron deficiency on pregnancy outcomes in malaria-endemic regions. METHODS We determined iron deficiency in a cohort of 279 pregnant women in a malaria-endemic area of Papua New Guinea. Associations with birth weight, LBW and PTB were estimated using linear and logistic regression. A causal model using sequential mediation analyses was constructed to assess the association between iron deficiency and LBW, either independently or mediated through malaria and/or anaemia. RESULTS Iron deficiency in pregnant women was common (71% at enrolment) and associated with higher mean birth weights (230 g; 95% confidence interval, CI 118, 514; p < 0.001), and reduced odds of LBW (adjusted odds ratio, aOR = 0.32; 95% CI 0.16, 0.64; p = 0.001) and PTB (aOR = 0.57; 95% CI 0.30, 1.09; p = 0.089). Magnitudes of effect were greatest in primigravidae (birth weight 351 g; 95% CI 188, 514; p < 0.001; LBW aOR 0.26; 95% CI 0.10, 0.66; p = 0.005; PTB aOR = 0.39, 95% CI 0.16, 0.97; p = 0.042). Sequential mediation analyses indicated that the protective association of iron deficiency on LBW was mainly mediated through mechanisms independent of malaria or anaemia. CONCLUSIONS Iron deficiency was associated with substantially reduced odds of LBW predominantly through malaria-independent protective mechanisms, which has substantial implications for understanding risks for poor pregnancy outcomes and evaluating the benefit of iron supplementation in pregnancy. This study is the first longitudinal study to demonstrate a temporal relationship between antenatal iron deficiency and improved birth outcomes. These findings suggest that iron supplementation needs to be integrated with other strategies to prevent or treat infections and undernutrition in pregnancy to achieve substantial improvements in birth outcomes.
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15
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Saraiva RG, Huitt-Roehl CR, Tripathi A, Cheng YQ, Bosch J, Townsend CA, Dimopoulos G. Chromobacterium spp. mediate their anti-Plasmodium activity through secretion of the histone deacetylase inhibitor romidepsin. Sci Rep 2018; 8:6176. [PMID: 29670144 PMCID: PMC5906607 DOI: 10.1038/s41598-018-24296-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 03/19/2018] [Indexed: 12/03/2022] Open
Abstract
The Chromobacterium sp. Panama bacterium has in vivo and in vitro anti-Plasmodium properties. To assess the nature of the Chromobacterium-produced anti-Plasmodium factors, chemical partition was conducted by bioassay-guided fractionation where different fractions were assayed for activity against asexual stages of P. falciparum. The isolated compounds were further partitioned by reversed-phase FPLC followed by size-exclusion chromatography; high resolution UPLC and ESI/MS data were then collected and revealed that the most active fraction contained a cyclic depsipeptide, which was identified as romidepsin. A pure sample of this FDA-approved HDAC inhibitor allowed us to independently verify this finding, and establish that romidepsin also has potent effect against mosquito stages of the parasite's life cycle. Genomic comparisons between C. sp. Panama and multiple species within the Chromobacterium genus further demonstrated a correlation between presence of the gene cluster responsible for romidepsin production and effective antiplasmodial activity. A romidepsin-null Chromobacterium spp. mutant loses its anti-Plasmodium properties by losing the ability to inhibit P. falciparum HDAC activity, and romidepsin is active against resistant parasites to commonly deployed antimalarials. This independent mode of action substantiates exploring a chromobacteria-based approach for malaria transmission-blocking.
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Affiliation(s)
- Raúl G Saraiva
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | | | - Abhai Tripathi
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Yi-Qiang Cheng
- UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Jürgen Bosch
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
- InterRayBio, LLC, Baltimore, Maryland, USA
| | - Craig A Townsend
- Department of Chemistry, Johns Hopkins University, Baltimore, MD, USA
| | - George Dimopoulos
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
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Laurent Q, Batchelor LK, Dyson PJ. Applying a Trojan Horse Strategy to Ruthenium Complexes in the Pursuit of Novel Antibacterial Agents. Organometallics 2018. [DOI: 10.1021/acs.organomet.7b00885] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Quentin Laurent
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Lucinda K. Batchelor
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Paul J. Dyson
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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17
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Dhusia K, Bajpai A, Ramteke PW. Overcoming antibiotic resistance: Is siderophore Trojan horse conjugation an answer to evolving resistance in microbial pathogens? J Control Release 2017; 269:63-87. [PMID: 29129658 DOI: 10.1016/j.jconrel.2017.11.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 10/30/2017] [Accepted: 11/01/2017] [Indexed: 01/11/2023]
Abstract
Comparative study of siderophore biosynthesis pathway in pathogens provides potential targets for antibiotics and host drug delivery as a part of computationally feasible microbial therapy. Iron acquisition using siderophore models is an essential and well established model in all microorganisms and microbial infections a known to cause great havoc to both plant and animal. Rapid development of antibiotic resistance in bacterial as well as fungal pathogens has drawn us at a verge where one has to get rid of the traditional way of obstructing pathogen using single or multiple antibiotic/chemical inhibitors or drugs. 'Trojan horse' strategy is an answer to this imperative call where antibiotic are by far sneaked into the pathogenic cell via the siderophore receptors at cell and outer membrane. This antibiotic once gets inside, generates a 'black hole' scenario within the opportunistic pathogens via iron scarcity. For pathogens whose siderophore are not compatible to smuggle drug due to their complex conformation and stiff valence bonds, there is another approach. By means of the siderophore biosynthesis pathways, potential targets for inhibition of these siderophores in pathogenic bacteria could be achieved and thus control pathogenic virulence. Method to design artificial exogenous siderophores for pathogens that would compete and succeed the battle of intake is also covered with this review. These manipulated siderophore would enter pathogenic cell like any other siderophore but will not disperse iron due to which iron inadequacy and hence pathogens control be accomplished. The aim of this review is to offer strategies to overcome the microbial infections/pathogens using siderophore.
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Affiliation(s)
- Kalyani Dhusia
- Deptartment of Computational Biology and Bioinformatics, Jacob Institute of Biotechnology and Bio-Engineering, Sam Higginbottom University of Agriculture, Technology and Sciences (SHUATS), Allahabad-211007 (U.P.), India
| | - Archana Bajpai
- Laboratory for Disease Systems Modeling, Center for Integrative Medical Sciences, RIKEN, Yokohama City, Kanagawa, 230-0045, Japan
| | - P W Ramteke
- Deptartment of Computational Biology and Bioinformatics, Jacob Institute of Biotechnology and Bio-Engineering, Sam Higginbottom University of Agriculture, Technology and Sciences (SHUATS), Allahabad-211007 (U.P.), India
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18
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Jackson LH, Vlachodimitropoulou E, Shangaris P, Roberts TA, Ryan TM, Campbell-Washburn AE, David AL, Porter JB, Lythgoe MF, Stuckey DJ. Non-invasive MRI biomarkers for the early assessment of iron overload in a humanized mouse model of β-thalassemia. Sci Rep 2017; 7:43439. [PMID: 28240317 PMCID: PMC5327494 DOI: 10.1038/srep43439] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 01/23/2017] [Indexed: 01/19/2023] Open
Abstract
β-thalassemia (βT) is a genetic blood disorder causing profound and life threatening anemia. Current clinical management of βT is a lifelong dependence on regular blood transfusions, a consequence of which is systemic iron overload leading to acute heart failure. Recent developments in gene and chelation therapy give hope of better prognosis for patients, but successful translation to clinical practice is hindered by the lack of thorough preclinical testing using representative animal models and clinically relevant quantitative biomarkers. Here we demonstrate a quantitative and non-invasive preclinical Magnetic Resonance Imaging (MRI) platform for the assessment of βT in the γβ0/γβA humanized mouse model of βT. Changes in the quantitative MRI relaxation times as well as severe splenomegaly were observed in the heart, liver and spleen in βT. These data showed high sensitivity to iron overload and a strong relationship between quantitative MRI relaxation times and hepatic iron content. Importantly these changes preceded the onset of iron overload cardiomyopathy, providing an early biomarker of disease progression. This work demonstrates that multiparametric MRI is a powerful tool for the assessment of preclinical βT, providing sensitive and quantitative monitoring of tissue iron sequestration and cardiac dysfunction- parameters essential for the preclinical development of new therapeutics.
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Affiliation(s)
- Laurence H Jackson
- Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London, UK
| | | | | | - Thomas A Roberts
- Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London, UK
| | - Thomas M Ryan
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Adrienne E Campbell-Washburn
- Laboratory of Imaging Technology, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA
| | - Anna L David
- Institute for Women's Health, University College London, London, UK
| | - John B Porter
- Department of Haematology, University College London, London, UK
| | - Mark F Lythgoe
- Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London, UK
| | - Daniel J Stuckey
- Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London, UK
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19
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Bahamontes-Rosa N, Alejandre AR, Gomez V, Viera S, Gomez-Lorenzo MG, Sanz-Alonso LM, Mendoza-Losana A. New molecular settings to support in vivo anti-malarial assays. Malar J 2016; 15:147. [PMID: 26955872 PMCID: PMC4784371 DOI: 10.1186/s12936-016-1205-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 03/01/2016] [Indexed: 11/27/2022] Open
Abstract
Background Quantitative real-time PCR (qPCR) is now commonly used as a method to confirm diagnosis of malaria and to differentiate recrudescence from re-infection, especially in clinical trials and in reference laboratories where precise quantification is critical. Although anti-malarial drug discovery is based on in vivo murine efficacy models, use of molecular analysis has been limited. The aim of this study was to develop qPCR as a valid methodology to support pre-clinical anti-malarial models by using filter papers to maintain material for qPCR and to compare this with traditional methods. Methods FTA technology (Whatman) is a rapid and safe method for extracting nucleic acids from blood. Peripheral blood samples from mice infected with Plasmodium berghei, P. yoelii, or P. falciparum were kept as frozen samples or as spots on FTA cards. The extracted genetic material from both types of samples was assessed for quantification by qPCR using sets of specific primers specifically designed for Plasmodium 18S rRNA, LDH, and CytB genes. Results The optimal conditions for nucleic acid extraction from FTA cards and qPCR amplification were set up, and were confirmed to be suitable for parasite quantification using DNA as template after storage at room temperature for as long as 26 months in the case of P. berghei samples and 52 months for P. falciparum and P. yoelii. The quality of DNA extracted from the FTA cards for gene sequencing and microsatellite amplification was also assessed. Conclusions This is the first study to report the suitability of FTA cards and qPCR assay to quantify parasite load in samples from in vivo efficacy models to support the drug discovery process.
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Latour C, Wlodarczyk MF, Jung G, Gineste A, Blanchard N, Ganz T, Roth MP, Coppin H, Kautz L. Erythroferrone contributes to hepcidin repression in a mouse model of malarial anemia. Haematologica 2016; 102:60-68. [PMID: 27658439 DOI: 10.3324/haematol.2016.150227] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Accepted: 09/14/2016] [Indexed: 01/10/2023] Open
Abstract
Malaria, a major global health challenge worldwide, is accompanied by a severe anemia secondary to hemolysis and increased erythrophagocytosis. Iron is an essential functional component of erythrocyte hemoglobin and its availability is controlled by the liver-derived hormone hepcidin. We examined the regulation of hepcidin during malarial infection in mice using the rodent parasite Plasmodium berghei K173. Mice infected with Plasmodium berghei K173 develop a severe anemia and die after 18 to 22 days without cerebral malaria. During the early phase of blood-stage infection (days 1 to 5), a strong inflammatory signature was associated with an increased production of hepcidin. Between days 7 and 18, while infection progressed, red blood cell count, hemoglobin and hematocrit dramatically decreased. In the late phase of malarial infection, hepcidin production was reduced concomitantly to an increase in the messenger RNA expression of the hepcidin suppressor erythroferrone in the bone marrow and the spleen. Compared with wild-type mice, Erfe-/- mice failed to adequately suppress hepcidin expression after infection with Plasmodium berghei K173. Importantly, the sustained production of hepcidin allowed by erythroferrone ablation was associated with decreased parasitemia, providing further evidence that transient iron restriction could be beneficial in the treatment of malaria.
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Affiliation(s)
- Chloé Latour
- IRSD, Université de Toulouse, INSERM U1220, INRA U1416, ENVT, UPS, Toulouse, France
| | - Myriam F Wlodarczyk
- CPTP, Université de Toulouse, CNRS U5282, Inserm U1043, UPS, Toulouse, France
| | - Grace Jung
- Department of Pathology, David Geffen School of Medicine, University of California, Los Angeles, USA
| | - Aurélie Gineste
- IRSD, Université de Toulouse, INSERM U1220, INRA U1416, ENVT, UPS, Toulouse, France
| | - Nicolas Blanchard
- CPTP, Université de Toulouse, CNRS U5282, Inserm U1043, UPS, Toulouse, France
| | - Tomas Ganz
- Department of Pathology, David Geffen School of Medicine, University of California, Los Angeles, USA.,Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, USA
| | - Marie-Paule Roth
- IRSD, Université de Toulouse, INSERM U1220, INRA U1416, ENVT, UPS, Toulouse, France
| | - Hélène Coppin
- IRSD, Université de Toulouse, INSERM U1220, INRA U1416, ENVT, UPS, Toulouse, France
| | - Léon Kautz
- IRSD, Université de Toulouse, INSERM U1220, INRA U1416, ENVT, UPS, Toulouse, France
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Slavic K, Krishna S, Lahree A, Bouyer G, Hanson KK, Vera I, Pittman JK, Staines HM, Mota MM. A vacuolar iron-transporter homologue acts as a detoxifier in Plasmodium. Nat Commun 2016; 7:10403. [PMID: 26786069 PMCID: PMC4735874 DOI: 10.1038/ncomms10403] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Accepted: 12/07/2015] [Indexed: 01/03/2023] Open
Abstract
Iron is an essential micronutrient but is also highly toxic. In yeast and plant cells, a key detoxifying mechanism involves iron sequestration into intracellular storage compartments, mediated by members of the vacuolar iron-transporter (VIT) family of proteins. Here we study the VIT homologue from the malaria parasites Plasmodium falciparum (PfVIT) and Plasmodium berghei (PbVIT). PfVIT-mediated iron transport in a yeast heterologous expression system is saturable (Km ∼ 14.7 μM), and selective for Fe(2+) over other divalent cations. PbVIT-deficient P. berghei lines (Pbvit(-)) show a reduction in parasite load in both liver and blood stages of infection in mice. Moreover, Pbvit(-) parasites have higher levels of labile iron in blood stages and are more sensitive to increased iron levels in liver stages, when compared with wild-type parasites. Our data are consistent with Plasmodium VITs playing a major role in iron detoxification and, thus, normal development of malaria parasites in their mammalian host.
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Affiliation(s)
- Ksenija Slavic
- Instituto de Medicina Molecular, Faculdade de Medicina Universidade de Lisboa, 1649-028 Lisbon, Portugal
| | - Sanjeev Krishna
- Institute for Infection & Immunity, St. George's, University of London, London SW17 0RE, UK
| | - Aparajita Lahree
- Instituto de Medicina Molecular, Faculdade de Medicina Universidade de Lisboa, 1649-028 Lisbon, Portugal
| | - Guillaume Bouyer
- Institute for Infection & Immunity, St. George's, University of London, London SW17 0RE, UK
- Sorbonne Universités, UPMC Univ Paris 6, CNRS, UMR 8227, Comparative Physiology of Erythrocytes, Station Biologique de Roscoff, CS 90074, 29688 Roscoff, France
| | - Kirsten K. Hanson
- Instituto de Medicina Molecular, Faculdade de Medicina Universidade de Lisboa, 1649-028 Lisbon, Portugal
- Present address: University of Texas at San Antonio, Department of Biology and STCEID, San Antonio, Texas 78249, USA
| | - Iset Vera
- Instituto de Medicina Molecular, Faculdade de Medicina Universidade de Lisboa, 1649-028 Lisbon, Portugal
| | - Jon K. Pittman
- Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Henry M. Staines
- Institute for Infection & Immunity, St. George's, University of London, London SW17 0RE, UK
| | - Maria M. Mota
- Instituto de Medicina Molecular, Faculdade de Medicina Universidade de Lisboa, 1649-028 Lisbon, Portugal
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Dambuza NS, Smith P, Evans A, Norman J, Taylor D, Andayi A, Egan T, Chibale K, Wiesner L. Antiplasmodial activity, in vivo pharmacokinetics and anti-malarial efficacy evaluation of hydroxypyridinone hybrids in a mouse model. Malar J 2015; 14:505. [PMID: 26671222 PMCID: PMC4681141 DOI: 10.1186/s12936-015-1032-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 12/02/2015] [Indexed: 12/03/2022] Open
Abstract
Background During the erythrocytic stage in humans, malaria parasites digest haemoglobin of the host cell, and the toxic haem moiety crystallizes into haemozoin. Chloroquine acts by forming toxic complexes with haem molecules and interfering with their crystallization. In chloroquine-resistant strains, the drug is excluded from the site of action, which causes the parasites to accumulate less chloroquine in their acid food vacuoles than chloroquine-sensitive parasites. 3-Hydroxylpyridin-4-ones are known to chelate iron; hydroxypyridone-chloroquine (HPO-CQ) hybrids were synthesized in order to determine whether they can inhibit parasites proliferation in the parasitic digestive vacuole by withholding iron from plasmodial parasite metabolic pathway. Methods Two HPO-CQ hybrids were tested against Plasmodium falciparum chloroquine-sensitive (D10 and 3D7) and -resistant strains (Dd2 and K1). The pharmacokinetic properties of active compounds were determined using a mouse model and blood samples were collected at different time intervals and analysed using LC–MS/MS. For in vivo efficacy the mice were infected with Plasmodium berghei in a 4-day Peters’ test. The parasitaemia was determined from day 3 and the course of the infection was followed by microscopic examination of stained blood films every 2–3 days until a rise in parasitaemia was observed in all test subjects. Results IC50 values of the two compounds for sensitive and resistant strains were 0.064 and 0.047 µM (compound 1), 0.041 and 0.122 µM (compound 2) and 0.505 and 0.463 µM (compound 1), 0.089 and 0.076 µM (compound 2), respectively. Pharmacokinetic evaluation of these compounds showed low oral bioavailability and this affected in vivo efficacy when compounds were dosed orally. However, when dosed intravenously compound 1 showed a clearance rate of 28 ml/min/kg, an apparent volume of distribution of 20 l/kg and a half-life of 4.3 h. A reduction in parasitaemia was observed when compound 1 was dosed intravenously for four consecutive days in P. berghei-infected mice. However, a rise in parasitaemia levels was observed on day 6 and on day 9 for chloroquine-treated mice. Conclusion The hybrid compounds that were tested were able to reduce parasitaemia levels in P. berghei-infected mice when dosed intravenously, but parasites recrudesced 24 h after the administration of the least dose. Despite low oral bioavailability, the IV data obtained suggests that further structural modifications may lead to the identification of more HPO-CQ hybrids with improved pharmacokinetic properties and in vivo efficacy.
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Affiliation(s)
- Ntokozo S Dambuza
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, Cape Town, 7925, South Africa.
| | - Peter Smith
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, Cape Town, 7925, South Africa.
| | - Alicia Evans
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, Cape Town, 7925, South Africa.
| | - Jennifer Norman
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, Cape Town, 7925, South Africa.
| | - Dale Taylor
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, Cape Town, 7925, South Africa.
| | - Andrew Andayi
- Department of Chemistry, University of Cape Town, Rondebosch, Cape Town, 7700, South Africa.
| | - Timothy Egan
- Department of Chemistry, University of Cape Town, Rondebosch, Cape Town, 7700, South Africa.
| | - Kelly Chibale
- Department of Chemistry, University of Cape Town, Rondebosch, Cape Town, 7700, South Africa.
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, Cape Town, 7925, South Africa.
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Thipubon P, Tipsuwan W, Uthaipibull C, Santitherakul S, Srichairatanakool S. Anti-malarial effect of 1-(N-acetyl-6-aminohexyl)-3-hydroxy-2-methylpyridin-4-one and green tea extract on erythrocyte-stage Plasmodium berghei in mice. Asian Pac J Trop Biomed 2015. [DOI: 10.1016/j.apjtb.2015.07.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Raiten DJ, Ashour FA. Iron: Current Landscape and Efforts to Address a Complex Issue in a Complex World. J Pediatr 2015; 167:S3-7. [PMID: 26364022 DOI: 10.1016/j.jpeds.2015.07.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Daniel J Raiten
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD.
| | - Fayrouz A Ashour
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, the National Institutes of Health, Bethesda, MD
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Dynamic control of hepatic Plasmodium numbers by hepcidin despite elevated liver iron during iron supplementation. Microbes Infect 2015; 18:48-56. [PMID: 26384816 DOI: 10.1016/j.micinf.2015.08.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 08/31/2015] [Accepted: 08/31/2015] [Indexed: 12/21/2022]
Abstract
Treatment of iron deficiency anemia in malaria endemic areas is complicated as iron supplementation increases malaria risk while malaria decreases iron absorption. Here we measured the influence of hepcidin expression and non-heme iron during iron supplementation on hepatic Plasmodium berghei numbers in anemic and non-anemic mice. Despite elevated hepatic non-heme iron on the high iron diet, elevated hepcidin expression is associated with less parasite bioavailable iron and lower hepatic parasite loads in anemic, iron deficient mice after both two and six weeks of supplementation. A marginal trend to lower parasite hepatic numbers was seen in non-anemic, iron replete mice. In a transgenic model of severe anemia, mice with a deletion in Sec15l1, which reportedly have normal liver iron and normal hepcidin expression, there were no changes in liver parasite numbers or blood stage numbers or outcome in the lethal Plasmodium yoelii model. In summary during iron supplementation the lower hepatic malaria numbers are regulated more by hepcidin than the absolute level of non-heme hepatic iron.
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Antimalarial iron chelator FBS0701 blocks transmission by Plasmodium falciparum gametocyte activation inhibition. Antimicrob Agents Chemother 2014; 59:1418-26. [PMID: 25512427 DOI: 10.1128/aac.04642-14] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Reducing the transmission of the malarial parasite by Anopheles mosquitoes using drugs or vaccines remains a main focus in the efforts to control malaria. Iron chelators have been studied as potential antimalarial drugs due to their activities against different stages of the parasite. The iron chelator FBS0701 affects the development of Plasmodium falciparum early gametocytes and lowers blood-stage parasitemia. Here, we tested the effect of FBS0701 on stage V gametocyte infectivity for mosquitoes. The incubation of stage V gametocytes for up to 3 days with increasing concentrations of FBS0701 resulted in a significant dose-related reduction in mosquito infectivity, as measured by the numbers of oocysts per mosquito. The reduction in mosquito infectivity was due to the inhibition of male and female gametocyte activation. The preincubation of FBS0701 with ferric chloride restored gametocyte infectivity, showing that the inhibitory effect of FBS0701 was quenched by iron. Deferoxamine, another iron chelator, also reduced gametocyte infectivity but to a lesser extent. Finally, the simultaneous administration of drug and gametocytes to mosquitoes without previous incubation did not significantly reduce the numbers of oocysts. These results show the importance of gametocyte iron metabolism as a potential target for new transmission-blocking strategies.
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Ramirez JL, Short SM, Bahia AC, Saraiva RG, Dong Y, Kang S, Tripathi A, Mlambo G, Dimopoulos G. Chromobacterium Csp_P reduces malaria and dengue infection in vector mosquitoes and has entomopathogenic and in vitro anti-pathogen activities. PLoS Pathog 2014; 10:e1004398. [PMID: 25340821 PMCID: PMC4207801 DOI: 10.1371/journal.ppat.1004398] [Citation(s) in RCA: 189] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Accepted: 08/14/2014] [Indexed: 11/27/2022] Open
Abstract
Plasmodium and dengue virus, the causative agents of the two most devastating vector-borne diseases, malaria and dengue, are transmitted by the two most important mosquito vectors, Anopheles gambiae and Aedes aegypti, respectively. Insect-bacteria associations have been shown to influence vector competence for human pathogens through multi-faceted actions that include the elicitation of the insect immune system, pathogen sequestration by microbes, and bacteria-produced anti-pathogenic factors. These influences make the mosquito microbiota highly interesting from a disease control perspective. Here we present a bacterium of the genus Chromobacterium (Csp_P), which was isolated from the midgut of field-caught Aedes aegypti. Csp_P can effectively colonize the mosquito midgut when introduced through an artificial nectar meal, and it also inhibits the growth of other members of the midgut microbiota. Csp_P colonization of the midgut tissue activates mosquito immune responses, and Csp_P exposure dramatically reduces the survival of both the larval and adult stages. Ingestion of Csp_P by the mosquito significantly reduces its susceptibility to Plasmodium falciparum and dengue virus infection, thereby compromising the mosquito's vector competence. This bacterium also exerts in vitro anti-Plasmodium and anti-dengue activities, which appear to be mediated through Csp_P -produced stable bioactive factors with transmission-blocking and therapeutic potential. The anti-pathogen and entomopathogenic properties of Csp_P render it a potential candidate for the development of malaria and dengue control strategies. The infectious agents that cause malaria and dengue are transmitted by Anopheles and Aedes mosquitoes, respectively. Bacteria found in the mosquito midgut have the potential to dramatically affect the susceptibility of the mosquito vector to the malaria parasite and dengue virus. In this work, we investigate one such microbe, Chromobacterium sp. (Csp_P), a bacterium isolated from a field-caught Aedes aegypti mosquito. We show that Csp_P can effectively colonize the midguts of Anopheles gambiae and Aedes aegypti mosquitoes and can, when ingested by the mosquito, significantly reduce the mosquito's susceptibility to infection with the malaria parasite and dengue virus. We also show that exposure to, and ingestion of, Csp_P can reduce the lifespan of larval and adult mosquitoes, respectively. We show that Csp_P has anti-Plasmodium and anti-dengue activity independent of the mosquito, suggesting that the bacterium secretes metabolites that could potentially be exploited to prevent disease transmission or to treat infection.
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Affiliation(s)
- Jose Luis Ramirez
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Sarah M. Short
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Ana C. Bahia
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Raul G. Saraiva
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Yuemei Dong
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Seokyoung Kang
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Abhai Tripathi
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Godfree Mlambo
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - George Dimopoulos
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
- * E-mail:
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Spottiswoode N, Duffy PE, Drakesmith H. Iron, anemia and hepcidin in malaria. Front Pharmacol 2014; 5:125. [PMID: 24910614 PMCID: PMC4039013 DOI: 10.3389/fphar.2014.00125] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 05/11/2014] [Indexed: 12/21/2022] Open
Abstract
Malaria and iron have a complex but important relationship. Plasmodium proliferation requires iron, both during the clinically silent liver stage of growth and in the disease-associated phase of erythrocyte infection. Precisely how the protozoan acquires its iron from its mammalian host remains unclear, but iron chelators can inhibit pathogen growth in vitro and in animal models. In humans, iron deficiency appears to protect against severe malaria, while iron supplementation increases risks of infection and disease. Malaria itself causes profound disturbances in physiological iron distribution and utilization, through mechanisms that include hemolysis, release of heme, dyserythropoiesis, anemia, deposition of iron in macrophages, and inhibition of dietary iron absorption. These effects have significant consequences. Malarial anemia is a major global health problem, especially in children, that remains incompletely understood and is not straightforward to treat. Furthermore, the changes in iron metabolism during a malaria infection may modulate susceptibility to co-infections. The release of heme and accumulation of iron in granulocytes may explain increased vulnerability to non-typhoidal Salmonella during malaria. The redistribution of iron away from hepatocytes and into macrophages may confer host resistance to superinfection, whereby blood-stage parasitemia prevents the development of a second liver-stage Plasmodium infection in the same organism. Key to understanding the pathophysiology of iron metabolism in malaria is the activity of the iron regulatory hormone hepcidin. Hepcidin is upregulated during blood-stage parasitemia and likely mediates much of the iron redistribution that accompanies disease. Understanding the regulation and role of hepcidin may offer new opportunities to combat malaria and formulate better approaches to treat anemia in the developing world.
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Affiliation(s)
- Natasha Spottiswoode
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of HealthBethesda, MD, USA
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of OxfordOxford, UK
| | - Patrick E. Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of HealthBethesda, MD, USA
| | - Hal Drakesmith
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of OxfordOxford, UK
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Conyers RC, Mazzone JR, Siegler MA, Tripathi AK, Sullivan DJ, Mott BT, Posner GH. The survival times of malaria-infected mice are prolonged more by several new two-carbon-linked artemisinin-derived dimer carbamates than by the trioxane antimalarial drug artemether. Bioorg Med Chem Lett 2014; 24:1285-9. [PMID: 24508128 PMCID: PMC3943161 DOI: 10.1016/j.bmcl.2014.01.059] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 01/13/2014] [Accepted: 01/21/2014] [Indexed: 10/25/2022]
Abstract
Sixteen new artemisinin-derived 2-carbon-linked trioxane dimers were prepared to study chemical structure/antimalarial activity relationships (SAR). Administering a very low single oral dose of only 5mg/kg of dimer secondary alcohol 6a or 6b plus 15 mg/kg of mefloquine hydrochloride prolonged the lives of Plasmodium berghei-infected mice to an average of 25 days after infection. This ACT chemotherapy result is of high medicinal significance because the antimalarial efficacy of the popular trioxane drug artemether (2) plus mefloquine under the same conditions was significantly lower (only 20 day average survival). NH-aryl carbamate derivatives 7e, 7i, and 7j of 2-carbon-linked dimer alcohol 6b also significantly outperformed artemether (2) in prolonging the survival times (25-27 days) of malaria-infected mice.
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Affiliation(s)
- Ryan C Conyers
- Department of Chemistry, School of Arts and Sciences, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, United States
| | - Jennifer R Mazzone
- Department of Chemistry, School of Arts and Sciences, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, United States
| | - Maxime A Siegler
- Department of Chemistry, School of Arts and Sciences, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, United States
| | - Abhai K Tripathi
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, MD 21205, United States; The Johns Hopkins Malaria Research Institute, Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, MD 21205, United States
| | - David J Sullivan
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, MD 21205, United States; The Johns Hopkins Malaria Research Institute, Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, MD 21205, United States
| | - Bryan T Mott
- Department of Chemistry, School of Arts and Sciences, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, United States
| | - Gary H Posner
- Department of Chemistry, School of Arts and Sciences, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, United States; The Johns Hopkins Malaria Research Institute, Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, MD 21205, United States.
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Abstract
The emergence of resistance to artemisinins and the renewed efforts to eradicate malaria demand the urgent development of new drugs. In this endeavour, the evaluation of efficacy in animal models is often a go/no go decision assay in drug discovery. This important role relies on the capability of animal models to assess the disposition, toxicology and efficacy of drugs in a single test. Although the relative merits of each efficacy model of malaria as human surrogate have been extensively discussed, there are no critical analyses on the use of such models in current drug discovery. In this article, we intend to analyse how efficacy models are used to discover new antimalarial drugs. Our analysis indicates that testing drug efficacy is often the last assay in each discovery stage and the experimental designs utilized are not optimized to expedite decision-making and inform clinical development. In light of this analysis, we propose new ways to accelerate drug discovery using efficacy models.
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Abstract
The discovery of new chemical starting points with the ability to inhibit Plasmodium falciparum sexual stages, and therefore block the disease transmission, is urgently required. These will form the basis for the development of new therapeutic combinations for the treatment and elimination of malaria and the ultimate goal of global eradication. Recent screening of large chemical libraries against the parasite asexual stages has resulted in the public availability of focused subsets of known antimalarial actives, which represent an excellent starting point for the identification of new gametocytocidal compounds. New stage-specific methodologies aimed at increasing the throughput for assessing compound activity against in vitro cultured gametocytes have recently been published. This article discusses the challenges of assay-oriented large-scale gametocyte culturing and reviews the state-of-the art in gametocytocidal assay development and outcomes.
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Clark M, Fisher NC, Kasthuri R, Cerami Hand C. Parasite maturation and host serum iron influence the labile iron pool of erythrocyte stage Plasmodium falciparum. Br J Haematol 2013; 161:262-9. [PMID: 23398516 DOI: 10.1111/bjh.12234] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 12/20/2012] [Indexed: 12/30/2022]
Abstract
Iron is a critical and tightly regulated nutrient for both the malaria parasite and its human host. The importance of the relationship between host iron and the parasite has been underscored recently by studies showing that host iron supplementation may increase the risk of falciparum malaria. It is unclear what host iron sources the parasite is able to access. We developed a flow cytometry-based method for measuring the labile iron pool (LIP) of parasitized erythrocytes using the nucleic acid dye STYO 61 and the iron sensitive dye, calcein acetoxymethyl ester (CA-AM). This new approach enabled us to measure the LIP of P. falciparum through the course of its erythrocytic life cycle and in response to the addition of host serum iron sources. We found that the LIP increases as the malaria parasite develops from early ring to late schizont stage, and that the addition of either transferrin or ferric citrate to culture media increases the LIP of trophozoites. Our method for detecting the LIP within malaria parasitized RBCs provides evidence that the parasite is able to access serum iron sources as part of the host vs. parasite arms race for iron.
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Affiliation(s)
- Martha Clark
- Department of Microbiology and Immunology, University of North Carolina-Chapel Hill, Chapel Hill, USA, United States
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Sullivan DJ. Plasmodium drug targets outside the genetic control of the parasite. Curr Pharm Des 2013; 19:282-289. [PMID: 22973888 PMCID: PMC4263254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 09/02/2012] [Indexed: 06/01/2023]
Abstract
Drug development often seeks to find "magic bullets" which target microbiologic proteins while not affecting host proteins. Paul Ehrlich tested methylene blue as an antimalarial but this dye was not superior to quinine. Many successful antimalarial therapies are "magic shotguns" which target many Plasmodium pathways with little interference in host metabolism. Two malaria drug classes, the 8- aminoquinolines and the artemisinins interact with cytochrome P450s and host iron protoporphyrin IX or iron, respectively, to generate toxic metabolites and/or radicals, which kill the parasite by interference with many proteins. The non 8-amino antimalarial quinolines like quinine or piperaquine bind heme to inhibit the process of heme crystallization, which results in multiple enzyme inhibition and membrane dysfunction. The quinolines and artemisinins are rapidly parasiticidal in contrast to metal chelators, which have a slower parasite clearance rate with higher drug concentrations. Iron chelators interfere with the artemisinins but otherwise represent a strategy of targeting multiple enzymes containing iron. Interest has been revived in antineoplastic drugs that target DNA metabolism as antimalarials. Specific drug targeting or investigation of the innate immunity directed to the more permeable trophozoite or schizont infected erythrocyte membrane has been under explored. Novel drug classes in the antimalarial development pipeline which either target multiple proteins or unchangeable cellular targets will slow the pace of drug resistance acquisition.
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Affiliation(s)
- David J Sullivan
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205 USA.
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Jacobine AM, Mazzone JR, Slack RD, Tripathi AK, Sullivan DJ, Posner GH. Malaria-infected mice live until at least day 30 after a new artemisinin-derived thioacetal thiocarbonate combined with mefloquine are administered together in a single, low, oral dose. J Med Chem 2012; 55:7892-9. [PMID: 22891714 PMCID: PMC3460521 DOI: 10.1021/jm3009986] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In only three steps and in 21-67% overall yields from the natural trioxane artemisinin, a series of 21 new trioxane C-10 thioacetals was prepared. Upon receiving a single oral dose of only 6 mg/kg of the monomeric trioxane 12c combined with 18 mg/kg of mefloquine hydrochloride, Plasmodium berghei-infected mice survived on average 29.8 days after infection. Two of the four mice in this group had no parasites detectable in their blood on day 30 after infection, and they behaved normally and appeared healthy. One of the mice had 11% blood parasitemia on day 30, and one mouse in this group died on day 29. Of high medicinal importance, the efficacy of this ACT chemotherapy is much better than (almost double) the efficacy under the same conditions using as a positive control the popular trioxane drug artemether plus mefloquine hydrochloride (average survival time of only 16.5 days).
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Affiliation(s)
- Alexander M. Jacobine
- Department of Chemistry, School of Arts and Sciences, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218
| | - Jennifer R. Mazzone
- Department of Chemistry, School of Arts and Sciences, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218
| | - Rachel D. Slack
- Department of Chemistry, School of Arts and Sciences, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218
| | - Abhai K. Tripathi
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205
- The Johns Hopkins Malaria Research Institute, Bloomberg School of Public Health, Baltimore, Maryland 21205
| | - David J. Sullivan
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205
- The Johns Hopkins Malaria Research Institute, Bloomberg School of Public Health, Baltimore, Maryland 21205
| | - Gary H. Posner
- Department of Chemistry, School of Arts and Sciences, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218
- The Johns Hopkins Malaria Research Institute, Bloomberg School of Public Health, Baltimore, Maryland 21205
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