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Targeting Artemisinin-Resistant Malaria by Repurposing the Anti-Hepatitis C Virus Drug Alisporivir. Antimicrob Agents Chemother 2022; 66:e0039222. [PMID: 36374050 PMCID: PMC9765015 DOI: 10.1128/aac.00392-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The emergence of Plasmodium falciparum resistance raises an urgent need to find new antimalarial drugs. Here, we report the rational repurposing of the anti-hepatitis C virus drug, alisporivir, a nonimmunosuppressive analog of cyclosporin A, against artemisinin-resistant strains of P. falciparum. In silico docking studies and molecular dynamic simulation predicted strong interaction of alisporivir with PfCyclophilin 19B, confirmed through biophysical assays with a Kd value of 354.3 nM. Alisporivir showed potent antimalarial activity against chloroquine-resistant (PfRKL-9 with resistance index [Ri] 2.14 ± 0.23) and artemisinin-resistant (PfKelch13R539T with Ri 1.15 ± 0.04) parasites. The Ri is defined as the ratio between the IC50 values of the resistant line to that of the sensitive line. To further investigate the mechanism involved, we analyzed the expression level of PfCyclophilin 19B in artemisinin-resistant P. falciparum (PfKelch13R539T). Semiquantitative real-time transcript, Western blot, and immunofluorescence analyses confirmed the overexpression of PfCyclophilin 19B in PfKelch13R539T. A 50% inhibitory concentration in the nanomolar range, together with the targeting of PfCyclophilin 19B, suggests that alisporivir can be used in combination with artemisinin. Since artemisinin resistance slows the clearance of ring-stage parasites, we performed a ring survival assay on artemisinin-resistant strain PfKelch13R539T and found significant decrease in parasite survival with alisporivir. Alisporivir was found to act synergistically with dihydroartemisinin and increase its efficacy. Furthermore, alisporivir exhibited antimalarial activity in vivo. Altogether, with the rational target-based Repurposing of alisporivir against malaria, our results support the hypothesis that targeting resistance mechanisms is a viable approach toward dealing with drug-resistant parasite.
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Fréville A, Gnangnon B, Khelifa AS, Gissot M, Khalife J, Pierrot C. Deciphering the Role of Protein Phosphatases in Apicomplexa: The Future of Innovative Therapeutics? Microorganisms 2022; 10:microorganisms10030585. [PMID: 35336160 PMCID: PMC8949495 DOI: 10.3390/microorganisms10030585] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/04/2022] [Accepted: 03/05/2022] [Indexed: 12/10/2022] Open
Abstract
Parasites belonging to the Apicomplexa phylum still represent a major public health and world-wide socioeconomic burden that is greatly amplified by the spread of resistances against known therapeutic drugs. Therefore, it is essential to provide the scientific and medical communities with innovative strategies specifically targeting these organisms. In this review, we present an overview of the diversity of the phosphatome as well as the variety of functions that phosphatases display throughout the Apicomplexan parasites’ life cycles. We also discuss how this diversity could be used for the design of innovative and specific new drugs/therapeutic strategies.
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Affiliation(s)
- Aline Fréville
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 9017-CIIL-Centre d’Infection et d’Immunité de Lille, 59000 Lille, France; (B.G.); (A.S.K.); (M.G.); (J.K.)
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Tropical Medicine and Hygiene, Keppel Street, London WC1E 7HT, UK
- Correspondence: (A.F.); (C.P.)
| | - Bénédicte Gnangnon
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 9017-CIIL-Centre d’Infection et d’Immunité de Lille, 59000 Lille, France; (B.G.); (A.S.K.); (M.G.); (J.K.)
- Department of Epidemiology, Center for Communicable Diseases Dynamics, Harvard TH Chan School of Public Health, Boston, MA 02115, USA
| | - Asma S. Khelifa
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 9017-CIIL-Centre d’Infection et d’Immunité de Lille, 59000 Lille, France; (B.G.); (A.S.K.); (M.G.); (J.K.)
| | - Mathieu Gissot
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 9017-CIIL-Centre d’Infection et d’Immunité de Lille, 59000 Lille, France; (B.G.); (A.S.K.); (M.G.); (J.K.)
| | - Jamal Khalife
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 9017-CIIL-Centre d’Infection et d’Immunité de Lille, 59000 Lille, France; (B.G.); (A.S.K.); (M.G.); (J.K.)
| | - Christine Pierrot
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 9017-CIIL-Centre d’Infection et d’Immunité de Lille, 59000 Lille, France; (B.G.); (A.S.K.); (M.G.); (J.K.)
- Correspondence: (A.F.); (C.P.)
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Fraser M, Matuschewski K, Maier AG. Of membranes and malaria: phospholipid asymmetry in Plasmodium falciparum-infected red blood cells. Cell Mol Life Sci 2021; 78:4545-4561. [PMID: 33713154 PMCID: PMC11071739 DOI: 10.1007/s00018-021-03799-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 02/04/2021] [Accepted: 02/23/2021] [Indexed: 11/29/2022]
Abstract
Malaria is a vector-borne parasitic disease with a vast impact on human history, and according to the World Health Organisation, Plasmodium parasites still infect over 200 million people per year. Plasmodium falciparum, the deadliest parasite species, has a remarkable ability to undermine the host immune system and cause life-threatening disease during blood infection. The parasite's host cells, red blood cells (RBCs), generally maintain an asymmetric distribution of phospholipids in the two leaflets of the plasma membrane bilayer. Alterations to this asymmetry, particularly the exposure of phosphatidylserine (PS) in the outer leaflet, can be recognised by phagocytes. Because of the importance of innate immune defence numerous studies have investigated PS exposure in RBCs infected with P. falciparum, but have reached different conclusions. Here we review recent advancements in our understanding of the molecular mechanisms which regulate asymmetry in RBCs, and whether infection with the P. falciparum parasite results in changes to PS exposure. On the balance of evidence, it is likely that membrane asymmetry is disrupted in parasitised RBCs, though some methodological issues need addressing. We discuss the potential causes and consequences of altered asymmetry in parasitised RBCs, particularly for in vivo interactions with the immune system, and the role of host-parasite co-evolution. We also examine the potential asymmetric state of parasite membranes and summarise current knowledge on the parasite proteins, which could regulate asymmetry in these membranes. Finally, we highlight unresolved questions at this time and the need for interdisciplinary approaches to uncover the machinery which enables P. falciparum parasites to hide in mature erythrocytes.
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Affiliation(s)
- Merryn Fraser
- Research School of Biology, The Australian National University, Canberra, Australia
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Berlin, Germany
| | - Kai Matuschewski
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Berlin, Germany
| | - Alexander G Maier
- Research School of Biology, The Australian National University, Canberra, Australia.
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Repurposing Drugs to Fight Hepatic Malaria Parasites. Molecules 2020; 25:molecules25153409. [PMID: 32731386 PMCID: PMC7435416 DOI: 10.3390/molecules25153409] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 12/16/2022] Open
Abstract
Malaria remains one of the most prevalent infectious diseases worldwide, primarily affecting some of the most vulnerable populations around the globe. Despite achievements in the treatment of this devastating disease, there is still an urgent need for the discovery of new drugs that tackle infection by Plasmodium parasites. However, de novo drug development is a costly and time-consuming process. An alternative strategy is to evaluate the anti-plasmodial activity of compounds that are already approved for other purposes, an approach known as drug repurposing. Here, we will review efforts to assess the anti-plasmodial activity of existing drugs, with an emphasis on the obligatory and clinically silent liver stage of infection. We will also review the current knowledge on the classes of compounds that might be therapeutically relevant against Plasmodium in the context of other communicable diseases that are prevalent in regions where malaria is endemic. Repositioning existing compounds may constitute a faster solution to the current gap of prophylactic and therapeutic drugs that act on Plasmodium parasites, overall contributing to the global effort of malaria eradication.
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Boulet C, Doerig CD, Carvalho TG. Manipulating Eryptosis of Human Red Blood Cells: A Novel Antimalarial Strategy? Front Cell Infect Microbiol 2018; 8:419. [PMID: 30560094 PMCID: PMC6284368 DOI: 10.3389/fcimb.2018.00419] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 11/14/2018] [Indexed: 12/13/2022] Open
Abstract
Malaria is a major global health burden, affecting over 200 million people worldwide. Resistance against all currently available antimalarial drugs is a growing threat, and represents a major and long-standing obstacle to malaria eradication. Like many intracellular pathogens, Plasmodium parasites manipulate host cell signaling pathways, in particular programmed cell death pathways. Interference with apoptotic pathways by malaria parasites is documented in the mosquito and human liver stages of infection, but little is known about this phenomenon in the erythrocytic stages. Although mature erythrocytes have lost all organelles, they display a form of programmed cell death termed eryptosis. Numerous features of eryptosis resemble those of nucleated cell apoptosis, including surface exposure of phosphatidylserine, cell shrinkage and membrane ruffling. Upon invasion, Plasmodium parasites induce significant stress to the host erythrocyte, while delaying the onset of eryptosis. Many eryptotic inducers appear to have a beneficial effect on the course of malaria infection in murine models, but major gaps remain in our understanding of the underlying molecular mechanisms. All currently available antimalarial drugs have parasite-encoded targets, which facilitates the emergence of resistance through selection of mutations that prevent drug-target binding. Identifying host cell factors that play a key role in parasite survival will provide new perspectives for host-directed anti-malarial chemotherapy. This review focuses on the interrelationship between Plasmodium falciparum and the eryptosis of its host erythrocyte. We summarize the current knowledge in this area, highlight the different schools of thoughts and existing gaps in knowledge, and discuss future perspectives for host-directed therapies in the context of antimalarial drug discovery.
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Affiliation(s)
- Coralie Boulet
- Molecular Parasitology Laboratory, Department of Physiology, Anatomy and Microbiology, La Trobe University, Bundoora, VIC, Australia
| | - Christian D Doerig
- Infection and Immunity Program, Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, VIC, Australia
| | - Teresa G Carvalho
- Molecular Parasitology Laboratory, Department of Physiology, Anatomy and Microbiology, La Trobe University, Bundoora, VIC, Australia
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Human Cyclophilin B forms part of a multi-protein complex during erythrocyte invasion by Plasmodium falciparum. Nat Commun 2017; 8:1548. [PMID: 29146974 PMCID: PMC5691159 DOI: 10.1038/s41467-017-01638-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 10/04/2017] [Indexed: 12/13/2022] Open
Abstract
Invasion of human erythrocytes by Plasmodium falciparum merozoites involves multiple interactions between host receptors and their merozoite ligands. Here we report human Cyclophilin B as a receptor for PfRhopH3 during merozoite invasion. Localization and binding studies show that Cyclophilin B is present on the erythrocytes and binds strongly to merozoites. We demonstrate that PfRhopH3 binds to the RBCs and their treatment with Cyclosporin A prevents merozoite invasion. We also show a multi-protein complex involving Cyclophilin B and Basigin, as well as PfRhopH3 and PfRh5 that aids the invasion. Furthermore, we report identification of a de novo peptide CDP3 that binds Cyclophilin B and blocks invasion by up to 80%. Collectively, our data provide evidence of compounded interactions between host receptors and merozoite surface proteins and paves the way for developing peptide and small-molecules that inhibit the protein−protein interactions, individually or in toto, leading to abrogation of the invasion process. Invasion of red blood cells by Plasmodium falciparum is a complex process and relies on several receptor-ligand interactions. Here, the authors show that human cyclophilin B binds Plasmodium surface protein PfRhopH3 and that interruption of this interaction reduces invasion by 80%.
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Lang E, Bissinger R, Gulbins E, Lang F. Ceramide in the regulation of eryptosis, the suicidal erythrocyte death. Apoptosis 2015; 20:758-67. [PMID: 25637185 DOI: 10.1007/s10495-015-1094-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Similar to apoptosis of nucleated cells, erythrocytes may undergo eryptosis, a suicidal death characterized by cell shrinkage and phospholipid scrambling of the cell membrane leading to phosphatidylserine exposure at the cell surface. As eryptotic erythrocytes are rapidly cleared from circulating blood, excessive eryptosis may lead to anemia. Moreover, eryptotic erythrocytes may adhere to the vascular wall and thus impede microcirculation. Stimulators of eryptosis include osmotic shock, oxidative stress and energy depletion. Mechanisms involved in the stimulation eryptosis include ceramide formation which may result from phospholipase A2 dependent formation of platelet activating factor (PAF) with PAF dependent stimulation of sphingomyelinases. Enhanced erythrocytic ceramide formation is observed in fever, sepsis, HUS, uremia, hepatic failure, and Wilson's disease. Enhanced eryptosis is further observed in iron deficiency, phosphate depletion, dehydration, malignancy, malaria, sickle-cell anemia, beta-thalassemia and glucose-6-phosphate dehydrogenase-deficiency. Moreover, eryptosis is triggered by osmotic shock and a wide variety of xenobiotics, which are again partially effective by enhancing ceramide abundance. Ceramide formation is inhibited by high concentrations of urea. As shown in Wilson's disease, pharmacological interference with ceramide formation may be a therapeutic option in the treatment of eryptosis inducing clinical disorders.
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Affiliation(s)
- Elisabeth Lang
- Department of Physiology, University of Tuebingen, Gmelinstr. 5, 72076, Tuebingen, Germany
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Triggers, inhibitors, mechanisms, and significance of eryptosis: the suicidal erythrocyte death. BIOMED RESEARCH INTERNATIONAL 2015; 2015:513518. [PMID: 25821808 PMCID: PMC4364016 DOI: 10.1155/2015/513518] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 01/12/2015] [Accepted: 01/15/2015] [Indexed: 12/13/2022]
Abstract
Suicidal erythrocyte death or eryptosis is characterized by erythrocyte shrinkage, cell membrane blebbing, and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Triggers of eryptosis include Ca(2+) entry, ceramide formation, stimulation of caspases, calpain activation, energy depletion, oxidative stress, and dysregulation of several kinases. Eryptosis is triggered by a wide variety of xenobiotics. It is inhibited by several xenobiotics and endogenous molecules including NO and erythropoietin. The susceptibility of erythrocytes to eryptosis increases with erythrocyte age. Phosphatidylserine exposing erythrocytes adhere to the vascular wall by binding to endothelial CXC-Motiv-Chemokin-16/Scavenger-receptor for phosphatidylserine and oxidized low density lipoprotein (CXCL16). Phosphatidylserine exposing erythrocytes are further engulfed by phagocytosing cells and are thus rapidly cleared from circulating blood. Eryptosis eliminates infected or defective erythrocytes thus counteracting parasitemia in malaria and preventing detrimental hemolysis of defective cells. Excessive eryptosis, however, may lead to anemia and may interfere with microcirculation. Enhanced eryptosis contributes to the pathophysiology of several clinical disorders including metabolic syndrome and diabetes, malignancy, cardiac and renal insufficiency, hemolytic uremic syndrome, sepsis, mycoplasma infection, malaria, iron deficiency, sickle cell anemia, thalassemia, glucose 6-phosphate dehydrogenase deficiency, and Wilson's disease. Facilitating or inhibiting eryptosis may be a therapeutic option in those disorders.
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Lotharius J, Gamo-Benito FJ, Angulo-Barturen I, Clark J, Connelly M, Ferrer-Bazaga S, Parkinson T, Viswanath P, Bandodkar B, Rautela N, Bharath S, Duffy S, Avery VM, Möhrle JJ, Guy RK, Wells T. Repositioning: the fast track to new anti-malarial medicines? Malar J 2014; 13:143. [PMID: 24731288 PMCID: PMC4021201 DOI: 10.1186/1475-2875-13-143] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 03/23/2014] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Repositioning of existing drugs has been suggested as a fast track for developing new anti-malarial agents. The compound libraries of GlaxoSmithKline (GSK), Pfizer and AstraZeneca (AZ) comprising drugs that have undergone clinical studies in other therapeutic areas, but not achieved approval, and a set of US Food and Drug Administration (FDA)-approved drugs and other bio-actives were tested against Plasmodium falciparum blood stages. METHODS Molecules were tested initially against erythrocytic co-cultures of P. falciparum to measure proliferation inhibition using one of the following methods: SYBR®I dye DNA staining assay (3D7, K1 or NF54 strains); [(3)H] hypoxanthine radioisotope incorporation assay (3D7 and 3D7A strain); or 4',6-diamidino-2-phenylindole (DAPI) DNA imaging assay (3D7 and Dd2 strains). After review of the available clinical pharmacokinetic and safety data, selected compounds with low μM activity and a suitable clinical profile were tested in vivo either in a Plasmodium berghei four-day test or in the P. falciparum Pf3D7(0087/N9) huSCID 'humanized' mouse model. RESULTS Of the compounds included in the GSK and Pfizer sets, 3.8% (9/238) had relevant in vitro anti-malarial activity while 6/100 compounds from the AZ candidate drug library were active. In comparison, around 0.6% (24/3,800) of the FDA-approved drugs and other bio-actives were active. After evaluation of available clinical data, four investigational drugs, active in vitro were tested in the P. falciparum humanized mouse model: UK-112,214 (PAF-H1 inhibitor), CEP-701 (protein kinase inhibitor), CEP-1347 (protein kinase inhibitor), and PSC-833 (p-glycoprotein inhibitor). Only UK-112,214 showed significant efficacy against P. falciparum in vivo, although at high doses (ED90 131.3 mg/kg [95% CI 112.3, 156.7]), and parasitaemia was still present 96 hours after treatment commencement. Of the six actives from the AZ library, two compounds (AZ-1 and AZ-3) were marginally efficacious in vivo in a P. berghei model. CONCLUSIONS Repositioning of existing therapeutics in malaria is an attractive proposal. Compounds active in vitro at μM concentrations were identified. However, therapeutic concentrations may not be effectively achieved in mice or humans because of poor bio-availability and/or safety concerns. Stringent safety requirements for anti-malarial drugs, given their widespread use in children, make this a challenging area in which to reposition therapy.
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Affiliation(s)
- Julie Lotharius
- Medicines for Malaria Venture (MMV), PO Box 1826, 20 rte de Pré-Bois, 1215, Geneva 15, Switzerland
| | | | - Iñigo Angulo-Barturen
- Diseases of the Developing World Medicines Development Campus, GlaxoSmithKline, Madrid, Tres Cantos, Spain
| | - Julie Clark
- Department of Chemical Biology and Therapeutics, St Jude Children’s Research Hospital, Memphis, TN, USA
| | - Michele Connelly
- Department of Chemical Biology and Therapeutics, St Jude Children’s Research Hospital, Memphis, TN, USA
| | - Santiago Ferrer-Bazaga
- Diseases of the Developing World Medicines Development Campus, GlaxoSmithKline, Madrid, Tres Cantos, Spain
| | | | | | | | - Nikhil Rautela
- AstraZeneca India Pvt Ltd, Bellary Road, Hebbal, Bangalore, India
| | - Sowmya Bharath
- AstraZeneca India Pvt Ltd, Bellary Road, Hebbal, Bangalore, India
| | - Sandra Duffy
- Discovery Biology, Eskitis Institute for Drug Discovery, Griffith University, Nathan, Australia
| | - Vicky M Avery
- Discovery Biology, Eskitis Institute for Drug Discovery, Griffith University, Nathan, Australia
| | - Jörg J Möhrle
- Medicines for Malaria Venture (MMV), PO Box 1826, 20 rte de Pré-Bois, 1215, Geneva 15, Switzerland
| | - R Kiplin Guy
- Department of Chemical Biology and Therapeutics, St Jude Children’s Research Hospital, Memphis, TN, USA
| | - Timothy Wells
- Medicines for Malaria Venture (MMV), PO Box 1826, 20 rte de Pré-Bois, 1215, Geneva 15, Switzerland
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Ghashghaeinia M, Bobbala D, Wieder T, Koka S, Brück J, Fehrenbacher B, Röcken M, Schaller M, Lang F, Ghoreschi K. Targeting glutathione by dimethylfumarate protects against experimental malaria by enhancing erythrocyte cell membrane scrambling. Am J Physiol Cell Physiol 2010; 299:C791-804. [PMID: 20631250 DOI: 10.1152/ajpcell.00014.2010] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The balance between GSH-levels and oxidative stress is critical for cell survival. The GSH-levels of erythrocytes are dramatically decreased during infection with Plasmodium spp. We therefore investigated the consequences of targeting GSH for erythrocyte and Plasmodium survival in vitro and in vivo using dimethylfumarate (DMF) at therapeutically established dosage. We first show that noninfected red blood cells (RBC) exposed to DMF undergo changes typical of apoptosis or eryptosis, such as cell shrinkage and cell membrane scrambling with subsequent phosphatidylserine (PS) exposure. DMF did not induce appreciable hemolysis. DMF-triggered PS exposure was mediated by intracellular GSH depletion and reversed by the antioxidative N-acetyl-l-cysteine. DMF treatment controlled intraerythrocyte DNA amplification and in vitro parasitemia of Plasmodium falciparum-infected RBC. In vivo, DMF treatment had no effect on RBC count or GSH levels in noninfected mice. Consistent with its effects on infected RBC, DMF treatment abrogated parasitemia and enhanced the survival of mice infected with Plasmodium berghei from 0% to 60%. In conclusion, DMF sensitizes the erythrocytes to the effect of Plasmodium infection on PS exposure, thus accelerating the clearance of infected erythrocytes. Accordingly, DMF treatment favorably influences the clinical course of malaria. As DMF targets mechanisms within the host cell, it is not likely to generate resistance of the pathogen.
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Affiliation(s)
- Mehrdad Ghashghaeinia
- Physiologisches Institut der Universität Tübingen, Gmelinstr. 5, D-72076 Tübingen, Germany
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Alesutan I, Bobbala D, Qadri SM, Estremera A, Föller M, Lang F. Beneficial effect of aurothiomalate on murine malaria. Malar J 2010; 9:118. [PMID: 20459650 PMCID: PMC2875225 DOI: 10.1186/1475-2875-9-118] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2009] [Accepted: 05/07/2010] [Indexed: 12/29/2022] Open
Abstract
Background Premature death of Plasmodium-infected erythrocytes is considered to favourably influence the clinical course of malaria. Aurothiomalate has previously been shown to trigger erythrocyte death or eryptosis, which is characterized by cell membrane scrambling leading to phosphatidylserine exposure at the cell surface. Phosphatidylserine-exposing cells are rapidly cleared from circulating blood. The present study thus tested whether sodium aurothiomalate influences the intraerythrocytic parasite development in vitro and the clinical course of murine malaria in vivo. Methods Human erythrocytes were infected with Plasmodium falciparum BinH in vitro and mice were infected (intraperitoneal injection of 1 × 106 parasitized murine erythrocytes) with Plasmodium berghei ANKA in vivo. Results Exposure to aurothiomalate significantly decreased the in vitro parasitemia of P. falciparum-infected human erythrocytes without influencing the intraerythrocytic DNA/RNA content. Administration of sodium aurothiomalate in vivo (daily 10 mg/kg b.w. s.c. from the 8th day of infection) enhanced the percentage of phosphatidylserine-exposing infected and noninfected erythrocytes in blood. All nontreated mice died within 30 days of infection. Aurothiomalate-treatment delayed the lethal course of malaria leading to survival of more than 50% of the mice 30 days after infection. Conclusions Sodium aurothiomalate influences the survival of Plasmodium berghei-infected mice, an effect only partially explained by stimulation of eryptosis.
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Affiliation(s)
- Ioana Alesutan
- Department of Physiology, University of Tübingen, Gmelinstr, 5, 72076 Tübingen, Germany
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Bobbala D, Koka S, Geiger C, Föller M, Huber SM, Lang F. Azathioprine favourably influences the course of malaria. Malar J 2009; 8:102. [PMID: 19442289 PMCID: PMC2694830 DOI: 10.1186/1475-2875-8-102] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2009] [Accepted: 05/14/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Azathioprine triggers suicidal erythrocyte death or eryptosis, characterized by cell shrinkage and exposure of phosphatidylserine at the erythrocyte surface. Eryptosis may accelerate the clearance of Plasmodium-infected erythrocytes. The present study thus explored whether azathioprine influences eryptosis of Plasmodium-infected erythrocytes, development of parasitaemia and thus the course of malaria. METHODS Human erythrocytes were infected in vitro with Plasmodium falciparum (P. falciparum) (strain BinH) in the absence and presence of azathioprine (0.001 - 10 microM), parasitaemia determined utilizing Syto16, phosphatidylserine exposure estimated from annexin V-binding and cell volume from forward scatter in FACS analysis. Mice were infected with Plasmodium berghei (P. berghei) ANKA by injecting parasitized murine erythrocytes (1 x 106) intraperitoneally. Where indicated azathioprine (5 mg/kg b.w.) was administered subcutaneously from the eighth day of infection. RESULTS In vitro infection of human erythrocytes with P. falciparum increased annexin V-binding and initially decreased forward scatter, effects significantly augmented by azathioprine. At higher concentrations azathioprine significantly decreased intraerythrocytic DNA/RNA content (>or= 1 microM) and in vitro parasitaemia (>or= 1 microM). Administration of azathioprine significantly decreased the parasitaemia of circulating erythrocytes and increased the survival of P. berghei-infected mice (from 0% to 77% 22 days after infection). CONCLUSION Azathioprine inhibits intraerythrocytic growth of P. falciparum, enhances suicidal death of infected erythrocytes, decreases parasitaemia and fosters host survival during malaria.
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Affiliation(s)
- Diwakar Bobbala
- Department of Physiology, University of Tübingen, Tübingen, Germany.
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Bell A. Letter to the Editor on effect of cyclosporine on parasitemia and survival of Plasmodium berghei-infected mice. Biochem Biophys Res Commun 2009; 378:678-9; author reply 680-1. [PMID: 19032941 DOI: 10.1016/j.bbrc.2008.11.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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