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Sojka D, Šnebergerová P. Advances in protease inhibition-based chemotherapy: A decade of insights from Malaria research. ADVANCES IN PARASITOLOGY 2024; 126:205-227. [PMID: 39448191 DOI: 10.1016/bs.apar.2024.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2024]
Abstract
Over the last decade, research on the most studied parasite, Plasmodium falciparum, has disclosed significant findings in protease research. Detailed descriptions of the individual roles of protease isoenzymes from various protease classes encoded by the parasite genome have been elucidated, along with their functional and biochemical characterizations. These insights have enabled the development of innovative chemotherapy using low molecular weight inhibitors targeting specific molecular sites. Progress has been made in understanding the proteolytic cascade associated with the apical complex, particularly the roles of aspartyl proteases plasmepsins IX and X as master regulators. Additionally, advancements in direct and alternative methods of proteasome inhibition and expression regulation have been achieved. Research on digestive/food vacuole-associated proteases, with a focus on essential metalloproteases, has also seen significant developments. The rise of extensive genomic datasets and functional genomic tools for other parasitic organisms now allows these approaches to be applied to the study and treatment of other, less known parasitic diseases, aiming to uncover specific biological mechanisms and develop innovative, less toxic chemotherapies.
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Affiliation(s)
- Daniel Sojka
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Ceske Budejovice, Czech Republic.
| | - Pavla Šnebergerová
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Ceske Budejovice, Czech Republic; Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
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2
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Desai SA. Novel Ion Channel Genes in Malaria Parasites. Genes (Basel) 2024; 15:296. [PMID: 38540355 PMCID: PMC10970509 DOI: 10.3390/genes15030296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 02/19/2024] [Accepted: 02/23/2024] [Indexed: 06/14/2024] Open
Abstract
Ion channels serve many cellular functions including ion homeostasis, volume regulation, signaling, nutrient acquisition, and developmental progression. Although the complex life cycles of malaria parasites necessitate ion and solute flux across membranes, the whole-genome sequencing of the human pathogen Plasmodium falciparum revealed remarkably few orthologs of known ion channel genes. Contrasting with this, biochemical studies have implicated the channel-mediated flux of ions and nutritive solutes across several membranes in infected erythrocytes. Here, I review advances in the cellular and molecular biology of ion channels in malaria parasites. These studies have implicated novel parasite genes in the formation of at least two ion channels, with additional ion channels likely present in various membranes and parasite stages. Computational approaches that rely on homology to known channel genes from higher organisms will not be very helpful in identifying the molecular determinants of these activities. Given their unusual properties, novel molecular and structural features, and essential roles in pathogen survival and development, parasite channels should be promising targets for therapy development.
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Affiliation(s)
- Sanjay A Desai
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
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3
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Jonsdottir TK, Elsworth B, Cobbold S, Gabriela M, Ploeger E, Parkyn Schneider M, Charnaud SC, Dans MG, McConville M, Bullen HE, Crabb BS, Gilson PR. PTEX helps efficiently traffic haemoglobinases to the food vacuole in Plasmodium falciparum. PLoS Pathog 2023; 19:e1011006. [PMID: 37523385 PMCID: PMC10414648 DOI: 10.1371/journal.ppat.1011006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 08/10/2023] [Accepted: 07/16/2023] [Indexed: 08/02/2023] Open
Abstract
A key element of Plasmodium biology and pathogenesis is the trafficking of ~10% of the parasite proteome into the host red blood cell (RBC) it infects. To cross the parasite-encasing parasitophorous vacuole membrane, exported proteins utilise a channel-forming protein complex termed the Plasmodium translocon of exported proteins (PTEX). PTEX is obligatory for parasite survival, both in vitro and in vivo, suggesting that at least some exported proteins have essential metabolic functions. However, to date only one essential PTEX-dependent process, the new permeability pathways, has been described. To identify other essential PTEX-dependant proteins/processes, we conditionally knocked down the expression of one of its core components, PTEX150, and examined which pathways were affected. Surprisingly, the food vacuole mediated process of haemoglobin (Hb) digestion was substantially perturbed by PTEX150 knockdown. Using a range of transgenic parasite lines and approaches, we show that two major Hb proteases; falcipain 2a and plasmepsin II, interact with PTEX core components, implicating the translocon in the trafficking of Hb proteases. We propose a model where these proteases are translocated into the PV via PTEX in order to reach the cytostome, located at the parasite periphery, prior to food vacuole entry. This work offers a second mechanistic explanation for why PTEX function is essential for growth of the parasite within its host RBC.
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Affiliation(s)
- Thorey K. Jonsdottir
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
| | - Brendan Elsworth
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
| | - Simon Cobbold
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Melbourne, Australia
| | - Mikha Gabriela
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- School of Medicine, Deakin University, Geelong, Australia
| | - Ellen Ploeger
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
| | | | - Sarah C. Charnaud
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
| | - Madeline G. Dans
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
| | - Malcolm McConville
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Melbourne, Australia
| | - Hayley E. Bullen
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
| | - Brendan S. Crabb
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
- Department of Immunology and Pathology, Monash University, Melbourne, Australia
| | - Paul R. Gilson
- Malaria Virulence and Drug Discovery Group, Burnet Institute, Melbourne, Australia
- Department of Immunology and Microbiology, University of Melbourne, Melbourne, Australia
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4
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Lew VL. The circulatory dynamics of human red blood cell homeostasis: Oxy-deoxy and PIEZO1-triggered changes. Biophys J 2023; 122:484-495. [PMID: 36588342 PMCID: PMC9941722 DOI: 10.1016/j.bpj.2022.12.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 11/14/2022] [Accepted: 12/30/2022] [Indexed: 01/02/2023] Open
Abstract
The vital function of red blood cells (RBCs) is to mediate the transport of oxygen from lungs to tissues and of CO2 from tissues to lungs. The gas exchanges occur during capillary transits within fractions of a second. Each oxygenation-deoxygenation and deoxygenation-reoxygenation transition on hemoglobin triggers sharp changes in RBC pH, leading to downstream changes in ion fluxes, membrane potential, and cell volume. The dynamics of these changes during the variable periods between capillary transits in vivo remains a mystery inaccessible to study by current methodologies, a knowledge gap on a fundamental physiological process that is the focus of the present study. The use of a computational model of human RBC homeostasis of tested accreditation enabled a detailed investigation of the expected RBC changes during intercapillary transits, with results advancing novel insights and predictions. The predicted rates of relative RBC volume change on oxygenation-deoxygenation (oxy-deoxy) and deoxygenation-reoxygenation transitions were about 1.5%/min and -0.9%/min, respectively, far too slow to allow the cells to reach steady states in the intervals between capillary transits. The amplitude of the oxy-deoxy-reoxygenation volume fluctuations varied in proportion with the duration of the intercapillary transit intervals. Upon capillary entry, oxy-deoxy-induced changes occur concurrently with deformation-induced PIEZO1 channel activation, both processes affecting cell pH, membrane potential, and cell volume during intertransit periods. The model showed that the effects were strictly additive as expected from processes operating independently on the cell's homeostatic fabric. Analysis of the mechanisms behind these predictions revealed, for the first time, the complex interactions between oxy-deoxy and ion transport processes that ensure the long-term homeostatic stability of RBCs for optimal gas transport in physiological conditions and how these may become altered in diseased states. Possible designs of microfluidic devices to test the model predictions are discussed.
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Affiliation(s)
- Virgilio L Lew
- Physiological Laboratory, Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, United Kingdom.
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5
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Aguado ME, Izquierdo M, González-Matos M, Varela AC, Méndez Y, Del Rivero MA, Rivera DG, González-Bacerio J. Parasite Metalo-aminopeptidases as Targets in Human Infectious Diseases. Curr Drug Targets 2023; 24:416-461. [PMID: 36825701 DOI: 10.2174/1389450124666230224140724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 12/25/2022] [Accepted: 01/02/2023] [Indexed: 02/25/2023]
Abstract
BACKGROUND Parasitic human infectious diseases are a worldwide health problem due to the increased resistance to conventional drugs. For this reason, the identification of novel molecular targets and the discovery of new chemotherapeutic agents are urgently required. Metalo- aminopeptidases are promising targets in parasitic infections. They participate in crucial processes for parasite growth and pathogenesis. OBJECTIVE In this review, we describe the structural, functional and kinetic properties, and inhibitors, of several parasite metalo-aminopeptidases, for their use as targets in parasitic diseases. CONCLUSION Plasmodium falciparum M1 and M17 aminopeptidases are essential enzymes for parasite development, and M18 aminopeptidase could be involved in hemoglobin digestion and erythrocyte invasion and egression. Trypanosoma cruzi, T. brucei and Leishmania major acidic M17 aminopeptidases can play a nutritional role. T. brucei basic M17 aminopeptidase down-regulation delays the cytokinesis. The inhibition of Leishmania basic M17 aminopeptidase could affect parasite viability. L. donovani methionyl aminopeptidase inhibition prevents apoptosis but not the parasite death. Decrease in Acanthamoeba castellanii M17 aminopeptidase activity produces cell wall structural modifications and encystation inhibition. Inhibition of Babesia bovis growth is probably related to the inhibition of the parasite M17 aminopeptidase, probably involved in host hemoglobin degradation. Schistosoma mansoni M17 aminopeptidases inhibition may affect parasite development, since they could participate in hemoglobin degradation, surface membrane remodeling and eggs hatching. Toxoplasma gondii M17 aminopeptidase inhibition could attenuate parasite virulence, since it is apparently involved in the hydrolysis of cathepsin Cs- or proteasome-produced dipeptides and/or cell attachment/invasion processes. These data are relevant to validate these enzymes as targets.
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Affiliation(s)
- Mirtha E Aguado
- Center for Protein Studies, Faculty of Biology, University of Havana, Calle 25 #455 Entre I y J, 10400, Vedado, La Habana, Cuba
| | - Maikel Izquierdo
- Center for Protein Studies, Faculty of Biology, University of Havana, Calle 25 #455 Entre I y J, 10400, Vedado, La Habana, Cuba
| | - Maikel González-Matos
- Center for Protein Studies, Faculty of Biology, University of Havana, Calle 25 #455 Entre I y J, 10400, Vedado, La Habana, Cuba
| | - Ana C Varela
- Center for Protein Studies, Faculty of Biology, University of Havana, Calle 25 #455 Entre I y J, 10400, Vedado, La Habana, Cuba
| | - Yanira Méndez
- Center for Natural Products Research, Faculty of Chemistry, University of Havana, Zapata y G, 10400, La Habana, Cuba
| | - Maday A Del Rivero
- Center for Protein Studies, Faculty of Biology, University of Havana, Calle 25 #455 Entre I y J, 10400, Vedado, La Habana, Cuba
| | - Daniel G Rivera
- Center for Natural Products Research, Faculty of Chemistry, University of Havana, Zapata y G, 10400, La Habana, Cuba
| | - Jorge González-Bacerio
- Center for Protein Studies, Faculty of Biology, University of Havana, Calle 25 #455 Entre I y J, 10400, Vedado, La Habana, Cuba
- Department of Biochemistry, Faculty of Biology, University of Havana, calle 25 #455 entre I y J, 10400, Vedado, La Habana, Cuba
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6
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Haag M, Kehrer J, Sanchez CP, Deponte M, Lanzer M. Physiological jump in erythrocyte redox potential during Plasmodium falciparum development occurs independent of the sickle cell trait. Redox Biol 2022; 58:102536. [DOI: 10.1016/j.redox.2022.102536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/26/2022] [Accepted: 11/08/2022] [Indexed: 11/11/2022] Open
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7
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Leong YW, Russell B, Malleret B, Rénia L. Erythrocyte tropism of malarial parasites: The reticulocyte appeal. Front Microbiol 2022; 13:1022828. [PMID: 36386653 PMCID: PMC9643692 DOI: 10.3389/fmicb.2022.1022828] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 10/07/2022] [Indexed: 10/28/2023] Open
Abstract
Erythrocytes are formed from the enucleation of erythroblasts in the bone marrow, and as erythrocytes develop from immature reticulocytes into mature normocytes, they undergo extensive cellular changes through their passage in the blood. During the blood stage of the malarial parasite life cycle, the parasite sense and invade susceptible erythrocytes. However, different parasite species display varying erythrocyte tropisms (i.e., preference for either reticulocytes or normocytes). In this review, we explore the erythrocyte tropism of malarial parasites, especially their predilection to invade reticulocytes, as shown from recent studies. We also discuss possible mechanisms mediating erythrocyte tropism and the implications of specific tropisms to disease pathophysiology. Understanding these allows better insight into the role of reticulocytes in malaria and provides opportunities for targeted interventions.
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Affiliation(s)
- Yew Wai Leong
- A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research, Singapore, Singapore
| | - Bruce Russell
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Benoit Malleret
- Singapore Immunology Network, Agency for Science, Technology and Research, Singapore, Singapore
- Department of Microbiology and Immunology, Immunology Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Laurent Rénia
- A*STAR Infectious Diseases Labs, Agency for Science, Technology and Research, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
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8
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Okombo J, Mok S, Qahash T, Yeo T, Bath J, Orchard LM, Owens E, Koo I, Albert I, Llinás M, Fidock DA. Piperaquine-resistant PfCRT mutations differentially impact drug transport, hemoglobin catabolism and parasite physiology in Plasmodium falciparum asexual blood stages. PLoS Pathog 2022; 18:e1010926. [PMID: 36306287 PMCID: PMC9645663 DOI: 10.1371/journal.ppat.1010926] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 11/09/2022] [Accepted: 10/10/2022] [Indexed: 11/11/2022] Open
Abstract
The emergence of Plasmodium falciparum parasite resistance to dihydroartemisinin + piperaquine (PPQ) in Southeast Asia threatens plans to increase the global use of this first-line antimalarial combination. High-level PPQ resistance appears to be mediated primarily by novel mutations in the P. falciparum chloroquine resistance transporter (PfCRT), which enhance parasite survival at high PPQ concentrations in vitro and increase the risk of dihydroartemisinin + PPQ treatment failure in patients. Using isogenic Dd2 parasites expressing contemporary pfcrt alleles with differential in vitro PPQ susceptibilities, we herein characterize the molecular and physiological adaptations that define PPQ resistance in vitro. Using drug uptake and cellular heme fractionation assays we report that the F145I, M343L, and G353V PfCRT mutations differentially impact PPQ and chloroquine efflux. These mutations also modulate proteolytic degradation of host hemoglobin and the chemical inactivation of reactive heme species. Peptidomic analyses reveal significantly higher accumulation of putative hemoglobin-derived peptides in the PPQ-resistant mutant PfCRT isoforms compared to parental PPQ-sensitive Dd2. Joint transcriptomic and metabolomic profiling of late trophozoites from PPQ-resistant or -sensitive isogenic lines reveals differential expression of genes involved in protein translation and cellular metabolism. PPQ-resistant parasites also show increased susceptibility to an inhibitor of the P. falciparum M17 aminopeptidase that operates on short globin-derived peptides. These results reveal unique physiological changes caused by the gain of PPQ resistance and highlight the potential therapeutic value of targeting peptide metabolism in P. falciparum.
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Affiliation(s)
- John Okombo
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, New York, United States of America
| | - Sachel Mok
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, New York, United States of America
- Center for Malaria Therapeutics and Antimicrobial Resistance, Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, New York, United States of America
| | - Tarrick Qahash
- Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- Huck Center for Malaria Research, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Tomas Yeo
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, New York, United States of America
| | - Jade Bath
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, New York, United States of America
| | - Lindsey M. Orchard
- Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- Huck Center for Malaria Research, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Edward Owens
- Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- Huck Center for Malaria Research, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Imhoi Koo
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Istvan Albert
- Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Manuel Llinás
- Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- Huck Center for Malaria Research, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - David A. Fidock
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, New York, United States of America
- Center for Malaria Therapeutics and Antimicrobial Resistance, Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, New York, United States of America
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9
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Edgar RCS, Siddiqui G, Hjerrild K, Malcolm TR, Vinh NB, Webb CT, Holmes C, MacRaild CA, Chernih HC, Suen WW, Counihan NA, Creek DJ, Scammells PJ, McGowan S, de Koning-Ward TF. Genetic and chemical validation of Plasmodium falciparum aminopeptidase PfA-M17 as a drug target in the hemoglobin digestion pathway. eLife 2022; 11:e80813. [PMID: 36097817 PMCID: PMC9470162 DOI: 10.7554/elife.80813] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 08/02/2022] [Indexed: 11/18/2022] Open
Abstract
Plasmodium falciparum, the causative agent of malaria, remains a global health threat as parasites continue to develop resistance to antimalarial drugs used throughout the world. Accordingly, drugs with novel modes of action are desperately required to combat malaria. P. falciparum parasites infect human red blood cells where they digest the host's main protein constituent, hemoglobin. Leucine aminopeptidase PfA-M17 is one of several aminopeptidases that have been implicated in the last step of this digestive pathway. Here, we use both reverse genetics and a compound specifically designed to inhibit the activity of PfA-M17 to show that PfA-M17 is essential for P. falciparum survival as it provides parasites with free amino acids for growth, many of which are highly likely to originate from hemoglobin. We further show that loss of PfA-M17 results in parasites exhibiting multiple digestive vacuoles at the trophozoite stage. In contrast to other hemoglobin-degrading proteases that have overlapping redundant functions, we validate PfA-M17 as a potential novel drug target.
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Affiliation(s)
- Rebecca CS Edgar
- School of Medicine, Deakin UniversityGeelongAustralia
- The Institute for Mental and Physical Health and Clinical Translation, Deakin UniversityGeelongAustralia
| | - Ghizal Siddiqui
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleAustralia
| | | | - Tess R Malcolm
- Biomedicine Discovery Institute and Department of Microbiology, Monash UniversityClaytonAustralia
- Centre to Impact AMR, Monash UniversityMelbourneAustralia
| | - Natalie B Vinh
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleAustralia
| | - Chaille T Webb
- Biomedicine Discovery Institute and Department of Microbiology, Monash UniversityClaytonAustralia
- Centre to Impact AMR, Monash UniversityMelbourneAustralia
| | - Clare Holmes
- CSIRO Australian Centre for Disease PreparednessGeelongAustralia
| | - Christopher A MacRaild
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleAustralia
| | - Hope C Chernih
- School of Medicine, Deakin UniversityGeelongAustralia
- The Institute for Mental and Physical Health and Clinical Translation, Deakin UniversityGeelongAustralia
| | - Willy W Suen
- CSIRO Australian Centre for Disease PreparednessGeelongAustralia
| | - Natalie A Counihan
- School of Medicine, Deakin UniversityGeelongAustralia
- The Institute for Mental and Physical Health and Clinical Translation, Deakin UniversityGeelongAustralia
| | - Darren J Creek
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleAustralia
| | - Peter J Scammells
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleAustralia
| | - Sheena McGowan
- Biomedicine Discovery Institute and Department of Microbiology, Monash UniversityClaytonAustralia
- Centre to Impact AMR, Monash UniversityMelbourneAustralia
| | - Tania F de Koning-Ward
- School of Medicine, Deakin UniversityGeelongAustralia
- The Institute for Mental and Physical Health and Clinical Translation, Deakin UniversityGeelongAustralia
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10
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Matz JM. Plasmodium’s bottomless pit: properties and functions of the malaria parasite's digestive vacuole. Trends Parasitol 2022; 38:525-543. [DOI: 10.1016/j.pt.2022.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 02/21/2022] [Accepted: 02/21/2022] [Indexed: 11/30/2022]
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11
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Edgar RCS, Counihan NA, McGowan S, de Koning-Ward TF. Methods Used to Investigate the Plasmodium falciparum Digestive Vacuole. Front Cell Infect Microbiol 2022; 11:829823. [PMID: 35096663 PMCID: PMC8794586 DOI: 10.3389/fcimb.2021.829823] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 12/22/2021] [Indexed: 11/13/2022] Open
Abstract
Plasmodium falciparum malaria remains a global health problem as parasites continue to develop resistance to all antimalarials in use. Infection causes clinical symptoms during the intra-erythrocytic stage of the lifecycle where the parasite infects and replicates within red blood cells (RBC). During this stage, P. falciparum digests the main constituent of the RBC, hemoglobin, in a specialized acidic compartment termed the digestive vacuole (DV), a process essential for survival. Many therapeutics in use target one or multiple aspects of the DV, with chloroquine and its derivatives, as well as artemisinin, having mechanisms of action within this organelle. In order to better understand how current therapeutics and those under development target DV processes, techniques used to investigate the DV are paramount. This review outlines the involvement of the DV in therapeutics currently in use and focuses on the range of techniques that are currently utilized to study this organelle including microscopy, biochemical analysis, genetic approaches and metabolomic studies. Importantly, continued development and application of these techniques will aid in our understanding of the DV and in the development of new therapeutics or therapeutic partners for the future.
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Affiliation(s)
- Rebecca C. S. Edgar
- School of Medicine, Deakin University, Geelong, VIC, Australia
- The Institute for Mental and Physical Health and Clinical Translation, Deakin University, Geelong, VIC, Australia
| | - Natalie A. Counihan
- School of Medicine, Deakin University, Geelong, VIC, Australia
- The Institute for Mental and Physical Health and Clinical Translation, Deakin University, Geelong, VIC, Australia
| | - Sheena McGowan
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC, Australia
- Centre to Impact AMR, Monash University, Monash University, Clayton, VIC, Australia
| | - Tania F. de Koning-Ward
- School of Medicine, Deakin University, Geelong, VIC, Australia
- The Institute for Mental and Physical Health and Clinical Translation, Deakin University, Geelong, VIC, Australia
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12
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Hoff CC, Azevedo MF, Thurler AB, Maluf SEC, Melo PMS, del Rivero MA, González-Bacerio J, Carmona AK, Budu A, Gazarini ML. Overexpression of Plasmodium falciparum M1 Aminopeptidase Promotes an Increase in Intracellular Proteolysis and Modifies the Asexual Erythrocytic Cycle Development. Pathogens 2021; 10:pathogens10111452. [PMID: 34832608 PMCID: PMC8618464 DOI: 10.3390/pathogens10111452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 11/05/2021] [Accepted: 11/06/2021] [Indexed: 11/16/2022] Open
Abstract
Plasmodium falciparum, the most virulent of the human malaria parasite, is responsible for high mortality rates worldwide. We studied the M1 alanyl-aminopeptidase of this protozoan (PfA-M1), which is involved in the final stages of hemoglobin cleavage, an essential process for parasite survival. Aiming to help in the rational development of drugs against this target, we developed a new strain of P. falciparum overexpressing PfA-M1 without the signal peptide (overPfA-M1). The overPfA-M1 parasites showed a 2.5-fold increase in proteolytic activity toward the fluorogenic substrate alanyl-7-amido-4-methylcoumarin, in relation to the wild-type group. Inhibition studies showed that overPfA-M1 presented a lower sensitivity against the metalloaminopeptidase inhibitor bestatin and to other recombinant PfA-M1 inhibitors, in comparison with the wild-type strain, indicating that PfA-M1 is a target for the in vitro antimalarial activity of these compounds. Moreover, overPfA-M1 parasites present a decreased in vitro growth, showing a reduced number of merozoites per schizont, and also a decrease in the iRBC area occupied by the parasite in trophozoite and schizont forms when compared to the controls. Interestingly, the transgenic parasite displays an increase in the aminopeptidase activity toward Met-, Ala-, Leu- and Arg-7-amido-4-methylcoumarin. We also investigated the potential role of calmodulin and cysteine proteases in PfA-M1 activity. Taken together, our data show that the overexpression of PfA-M1 in the parasite cytosol can be a suitable tool for the screening of antimalarials in specific high-throughput assays and may be used for the identification of intracellular molecular partners that modulate their activity in P. falciparum.
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Affiliation(s)
- Carolina C. Hoff
- Department of Biosciences, Federal University of São Paulo, Santos 11015-020, Brazil; (C.C.H.); (M.F.A.)
| | - Mauro F. Azevedo
- Department of Biosciences, Federal University of São Paulo, Santos 11015-020, Brazil; (C.C.H.); (M.F.A.)
| | - Adriana B. Thurler
- Department of Biophysics, Federal University of São Paulo, São Paulo 04039-032, Brazil; (A.B.T.); (S.E.C.M.); (P.M.S.M.); (A.K.C.)
| | - Sarah El Chamy Maluf
- Department of Biophysics, Federal University of São Paulo, São Paulo 04039-032, Brazil; (A.B.T.); (S.E.C.M.); (P.M.S.M.); (A.K.C.)
| | - Pollyana M. S. Melo
- Department of Biophysics, Federal University of São Paulo, São Paulo 04039-032, Brazil; (A.B.T.); (S.E.C.M.); (P.M.S.M.); (A.K.C.)
| | - Maday Alonso del Rivero
- Center for Protein Studies, Faculty of Biology, University of Havana, Vedado, La Habana 10400, Cuba; (M.A.d.R.); (J.G.-B.)
| | - Jorge González-Bacerio
- Center for Protein Studies, Faculty of Biology, University of Havana, Vedado, La Habana 10400, Cuba; (M.A.d.R.); (J.G.-B.)
| | - Adriana K. Carmona
- Department of Biophysics, Federal University of São Paulo, São Paulo 04039-032, Brazil; (A.B.T.); (S.E.C.M.); (P.M.S.M.); (A.K.C.)
| | - Alexandre Budu
- Department of Biophysics, Federal University of São Paulo, São Paulo 04039-032, Brazil; (A.B.T.); (S.E.C.M.); (P.M.S.M.); (A.K.C.)
- Correspondence: (A.B.); (M.L.G.)
| | - Marcos L. Gazarini
- Department of Biosciences, Federal University of São Paulo, Santos 11015-020, Brazil; (C.C.H.); (M.F.A.)
- Correspondence: (A.B.); (M.L.G.)
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13
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González-Bacerio J, Izquierdo M, Aguado ME, Varela AC, González-Matos M, Del Rivero MA. Using microbial metalo-aminopeptidases as targets in human infectious diseases. MICROBIAL CELL 2021; 8:239-246. [PMID: 34692819 PMCID: PMC8485470 DOI: 10.15698/mic2021.10.761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 07/22/2021] [Accepted: 07/28/2021] [Indexed: 11/13/2022]
Abstract
Several microbial metalo-aminopeptidases are emerging as novel targets for the treatment of human infectious diseases. Some of them are well validated as targets and some are not; some are essential enzymes and others are important for virulence and pathogenesis. For another group, it is not clear if their enzymatic activity is involved in the critical functions that they mediate. But one aspect has been established: they display relevant roles in bacteria and protozoa that could be targeted for therapeutic purposes. This work aims to describe these biological functions for several microbial metalo-aminopeptidases.
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Affiliation(s)
- Jorge González-Bacerio
- Center for Protein Studies, Faculty of Biology, University of Havana, calle 25 #455 entre I y J, 10400, Vedado, La Habana, Cuba.,Department of Biochemistry, Faculty of Biology, University of Havana, calle 25 #455 entre I y J, 10400, Vedado, La Habana, Cuba
| | - Maikel Izquierdo
- Center for Protein Studies, Faculty of Biology, University of Havana, calle 25 #455 entre I y J, 10400, Vedado, La Habana, Cuba
| | - Mirtha Elisa Aguado
- Center for Protein Studies, Faculty of Biology, University of Havana, calle 25 #455 entre I y J, 10400, Vedado, La Habana, Cuba
| | - Ana C Varela
- Center for Protein Studies, Faculty of Biology, University of Havana, calle 25 #455 entre I y J, 10400, Vedado, La Habana, Cuba
| | - Maikel González-Matos
- Center for Protein Studies, Faculty of Biology, University of Havana, calle 25 #455 entre I y J, 10400, Vedado, La Habana, Cuba
| | - Maday Alonso Del Rivero
- Center for Protein Studies, Faculty of Biology, University of Havana, calle 25 #455 entre I y J, 10400, Vedado, La Habana, Cuba
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14
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In Vivo Antiplasmodial Activity and Toxicological Analyses of the Ethanolic Leaf and Twig Extract of Faurea speciosa Welw. (Proteaceae). J Parasitol Res 2021; 2021:7347532. [PMID: 34497722 PMCID: PMC8421164 DOI: 10.1155/2021/7347532] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 08/16/2021] [Indexed: 12/14/2022] Open
Abstract
In Africa, medicinal plants are commonly used to treat malaria and other diseased conditions. The ethanolic leaf and twig extract of Faurea speciosa has been shown to possess promising antiplasmodial properties. This present study was aimed at investigating its antiplasmodial effect in vivo. Qualitative phytochemical screening was carried out on the plant samples using standard methods. The antiplasmodial effect against early infection, curative effect against established infection, and prophylactic effect against residual infection were studied in vivo in Plasmodium berghei-infected mice while the carrageenan-induced edema model in chicks was used for anti-inflammatory tests. The phosphomolybdenum and DPPH radical scavenging assays were used in the evaluation of antioxidant potential. Acute toxicity of the extract was evaluated using the Organization for Economic Cooperation and Development (OECD) guidelines. Phytochemical screening of plant samples revealed the presence of flavonoids, coumarins, tannins, saponins, and glycosides. Faurea speciosa leaf and twig extract exhibited significant antiplasmodial activities in the mouse model with parasite suppression rates of 66.63%, 71.70%, and 56.93% in the suppressive, curative, and prophylactic tests, respectively. A 55.50% reduction of edema in the anti-inflammatory test indicated moderate success in reducing inflammation. The total antioxidant capacity of the extract was determined to be 65.4 mg AAE/g of extract, while in the DPPH radical scavenging assay, the IC50 value was found to be 499.4 μg/mL. With the exception of an inconsistent rise in urea level, there was no significant difference in the other biochemistry parameters in the acute toxicity studied. The median lethal dose (LD50) of the extract was over 2000 mg/kg. The results of this study show that Faurea speciosa leaf and twig extract has promising antimalarial capabilities and is fairly safe at low concentrations.
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15
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Clark MA, Kanjee U, Rangel GW, Chery L, Mascarenhas A, Gomes E, Rathod PK, Brugnara C, Ferreira MU, Duraisingh MT. Plasmodium vivax infection compromises reticulocyte stability. Nat Commun 2021; 12:1629. [PMID: 33712609 PMCID: PMC7955053 DOI: 10.1038/s41467-021-21886-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 02/17/2021] [Indexed: 12/21/2022] Open
Abstract
The structural integrity of the host red blood cell (RBC) is crucial for propagation of Plasmodium spp. during the disease-causing blood stage of malaria infection. To assess the stability of Plasmodium vivax-infected reticulocytes, we developed a flow cytometry-based assay to measure osmotic stability within characteristically heterogeneous reticulocyte and P. vivax-infected samples. We find that erythroid osmotic stability decreases during erythropoiesis and reticulocyte maturation. Of enucleated RBCs, young reticulocytes which are preferentially infected by P. vivax, are the most osmotically stable. P. vivax infection however decreases reticulocyte stability to levels close to those of RBC disorders that cause hemolytic anemia, and to a significantly greater degree than P. falciparum destabilizes normocytes. Finally, we find that P. vivax new permeability pathways contribute to the decreased osmotic stability of infected-reticulocytes. These results reveal a vulnerability of P. vivax-infected reticulocytes that could be manipulated to allow in vitro culture and develop novel therapeutics. During Plasmodium intra-erythrocytic developmental, parasites compromise the structural integrity of host red-blood cells. Here, Clark et al. develop a flow cytometric osmotic stability assay to show that P. vivax infection destabilizes host reticulocytes, which are less stable than P. falciparum-infected normocytes.
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Affiliation(s)
- Martha A Clark
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - Usheer Kanjee
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - Gabriel W Rangel
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA, USA
| | - Laura Chery
- Department of Chemistry, University of Washington, Seattle, WA, USA
| | - Anjali Mascarenhas
- Malaria Evolution in South Asia (MESA)-International Centers of Excellence in Malaria Research (ICEMR), Goa Medical College, Bambolim, Goa, India
| | - Edwin Gomes
- Malaria Evolution in South Asia (MESA)-International Centers of Excellence in Malaria Research (ICEMR), Goa Medical College, Bambolim, Goa, India
| | | | - Carlo Brugnara
- Department of Laboratory Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Marcelo U Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Manoj T Duraisingh
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA.
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16
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Aminobenzosuberone derivatives as PfA-M1 inhibitors: Molecular recognition and antiplasmodial evaluation. Bioorg Chem 2020; 98:103750. [DOI: 10.1016/j.bioorg.2020.103750] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 01/27/2020] [Accepted: 03/09/2020] [Indexed: 12/16/2022]
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17
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Martin RE. The transportome of the malaria parasite. Biol Rev Camb Philos Soc 2019; 95:305-332. [PMID: 31701663 DOI: 10.1111/brv.12565] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 10/02/2019] [Accepted: 10/04/2019] [Indexed: 12/15/2022]
Abstract
Membrane transport proteins, also known as transporters, control the movement of ions, nutrients, metabolites, and waste products across the membranes of a cell and are central to its biology. Proteins of this type also serve as drug targets and are key players in the phenomenon of drug resistance. The malaria parasite has a relatively reduced transportome, with only approximately 2.5% of its genes encoding transporters. Even so, assigning functions and physiological roles to these proteins, and ascertaining their contributions to drug action and drug resistance, has been very challenging. This review presents a detailed critique and synthesis of the disruption phenotypes, protein subcellular localisations, protein functions (observed or predicted), and links to antimalarial drug resistance for each of the parasite's transporter genes. The breadth and depth of the gene disruption data are particularly impressive, with at least one phenotype determined in the parasite's asexual blood stage for each transporter gene, and multiple phenotypes available for 76% of the genes. Analysis of the curated data set revealed there to be relatively little redundancy in the Plasmodium transportome; almost two-thirds of the parasite's transporter genes are essential or required for normal growth in the asexual blood stage of the parasite, and this proportion increased to 78% when the disruption phenotypes available for the other parasite life stages were included in the analysis. These observations, together with the finding that 22% of the transportome is implicated in the parasite's resistance to existing antimalarials and/or drugs within the development pipeline, indicate that transporters are likely to serve, or are already serving, as drug targets. Integration of the different biological and bioinformatic data sets also enabled the selection of candidates for transport processes known to be essential for parasite survival, but for which the underlying proteins have thus far remained undiscovered. These include potential transporters of pantothenate, isoleucine, or isopentenyl diphosphate, as well as putative anion-selective channels that may serve as the pore component of the parasite's 'new permeation pathways'. Other novel insights into the parasite's biology included the identification of transporters for the potential development of antimalarial treatments, transmission-blocking drugs, prophylactics, and genetically attenuated vaccines. The syntheses presented herein set a foundation for elucidating the functions and physiological roles of key members of the Plasmodium transportome and, ultimately, to explore and realise their potential as therapeutic targets.
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Affiliation(s)
- Rowena E Martin
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
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18
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Bounaadja L, Schmitt M, Albrecht S, Mouray E, Tarnus C, Florent I. Selective inhibition of PfA-M1, over PfA-M17, by an amino-benzosuberone derivative blocks malaria parasites development in vitro and in vivo. Malar J 2017; 16:382. [PMID: 28934959 PMCID: PMC5609037 DOI: 10.1186/s12936-017-2032-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 09/18/2017] [Indexed: 01/09/2023] Open
Abstract
Background Plasmodium falciparum M1 family aminopeptidase is currently considered as a promising target for anti-malarial chemotherapy. Several series of inhibitors developed by various research groups display IC50/Ki values down to nM range on native PfA-M1 or recombinant forms and block the parasite development in culture at µM to sub-µM concentrations. A handful of these inhibitors has been tested on murine models of malaria and has shown anti plasmodial in vivo activity. However, most of these inhibitors do also target the other neutral malarial aminopeptidase, PfA-M17, often with lower Ki values, which questions the relative involvement and importance of each enzyme in the parasite biology. Results An amino-benzosuberone derivative from a previously published collection of chemicals targeting specifically the M1-aminopeptidases has been identified; it is highly potent on PfA-M1 (Ki = 50 nM) and devoid of inhibitory activity on PfA-M17 (no inhibition up to 100 µM). This amino-benzosuberone derivative (T5) inhibits, in the µM range, the in vitro growth of two P. falciparum strains, 3D7 and FcB1, respectively chloroquino-sensitive and resistant. Evaluated in vivo, on the murine non-lethal model of malaria Plasmodium chabaudi chabaudi, this amino-benzosuberone derivative was able to reduce the parasite burden by 44 and 40% in a typical 4-day Peters assay at a daily dose of 12 and 24 mg/kg by intraperitoneal route of administration. Conclusions The evaluation of a highly selective inhibitor of PfA-M1, over PfA-M17, active on Plasmodium parasites in vitro and in vivo, highlights the relevance of PfA-M1 in the biological development of the parasite as well as in the list of promising anti-malarial targets to be considered in combination with current or future anti-malarial drugs. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-2032-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lotfi Bounaadja
- Molécules de Communication et Adaptation des Microorganismes, (MCAM, UMR7245), Muséum National Histoire Naturelle, Sorbonne Universités, CNRS, CP 52, 57 Rue Cuvier, 75005, Paris, France
| | - Marjorie Schmitt
- Laboratoire de Chimie Moléculaire, CNRS-UMR7509, Université de Strasbourg, 67037, Strasbourg Cedex 2, France
| | - Sébastien Albrecht
- Laboratoire de Chimie Organique et Bioorganique, EA4566, Université de Haute Alsace, 68093, Mulhouse Cedex, France
| | - Elisabeth Mouray
- Molécules de Communication et Adaptation des Microorganismes, (MCAM, UMR7245), Muséum National Histoire Naturelle, Sorbonne Universités, CNRS, CP 52, 57 Rue Cuvier, 75005, Paris, France
| | - Céline Tarnus
- Laboratoire de Chimie Organique et Bioorganique, EA4566, Université de Haute Alsace, 68093, Mulhouse Cedex, France
| | - Isabelle Florent
- Molécules de Communication et Adaptation des Microorganismes, (MCAM, UMR7245), Muséum National Histoire Naturelle, Sorbonne Universités, CNRS, CP 52, 57 Rue Cuvier, 75005, Paris, France.
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19
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Tiwari HK, Kumar P, Jatana N, Kumar K, Garg S, Narayanan L, Sijwali PS, Pandey KC, Gorobets NY, Dunn BM, Parmar VS, Singh BK. In Vitro Antimalarial Evaluation of Piperidine- and Piperazine-Based Chalcones: Inhibition of Falcipain-2 and Plasmepsin II Hemoglobinases Activities from Plasmodium falciparum. ChemistrySelect 2017. [DOI: 10.1002/slct.201701162] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Hemandra Kumar Tiwari
- Bio-organic Research Laboratory, Department of Chemistry; University of Delhi; Delhi-110007 India
| | - Prashant Kumar
- Bio-organic Research Laboratory, Department of Chemistry; University of Delhi; Delhi-110007 India
| | - Nidhi Jatana
- Bioinformatics Infrastructure Facility, Sri Venkateswara College; University of Delhi, South Campus; New Delhi-110021 India
| | - Krishan Kumar
- Bio-organic Research Laboratory, Department of Chemistry; University of Delhi; Delhi-110007 India
| | - Sandeep Garg
- Department of Zoology, Smt. Chandibai Himathmal Mansukhani College; University of Mumbai, Ulhasnagar; Thane Maharashtra-421003 India
| | - Latha Narayanan
- Bioinformatics Infrastructure Facility, Sri Venkateswara College; University of Delhi, South Campus; New Delhi-110021 India
| | - Puran Singh Sijwali
- CSIR-Centre for Cellular and Molecular Biology, Habsiguda; Hyderabad-500007, Andhra Pradesh India
| | - Kailash Chand Pandey
- National Institute of Malaria Research; Host-Parasite Interaction Biology Group, Lab No-219, Sector-8, Dwarka; New Delhi-110077 India
| | - Nickolay Yu Gorobets
- SSI ‘Institute for Single Crystals' of National Academy of Science of Ukraine; Lenina Ave 60 Kharkiv Ukraine
| | - Ben M. Dunn
- Department of Biochemistry and Molecular Biology; University of Florida College of Medicine; University of Florida, P. O.; Box-100245 Gainesville Florida-32610-0245 USA
| | - Virinder Singh Parmar
- Bio-organic Research Laboratory, Department of Chemistry; University of Delhi; Delhi-110007 India
- School of Chemical Science; Central University of Haryana; Mahendragarh Haryana-123031 India
- Institute of Advanced Sciences; North Dartmouth 86-410 Founce Corner Mall Road, MA 02747 USA
| | - Brajendra Kumar Singh
- Bio-organic Research Laboratory, Department of Chemistry; University of Delhi; Delhi-110007 India
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20
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Roy KK. Targeting the active sites of malarial proteases for antimalarial drug discovery: approaches, progress and challenges. Int J Antimicrob Agents 2017; 50:287-302. [PMID: 28668681 DOI: 10.1016/j.ijantimicag.2017.04.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 04/12/2017] [Accepted: 04/27/2017] [Indexed: 02/08/2023]
Abstract
Malaria is an infectious disease causing vast mortality and morbidity worldwide. Although antimalarial drugs are effective in several parts of the world, there is a serious threat to malaria control as malaria parasites are continuously developing widespread resistance against currently available antimalarial drugs, including artemisinin. Such widespread antimalarial drug resistance confirms the need to improve the efficacy of existing or new drugs as well as to develop alternative treatments through the identification of novel drug targets and the development of candidate drugs. Similar to proteases in other parasitic diseases such as leishmaniasis, schistosomiasis, Chagas disease and African sleeping sickness, malarial proteases constitute the major virulence factors in malaria. Malarial proteases belong to several classes and many of them have been targeted for the design and discovery of antimalarial agents. This review summarises the approaches, progress and challenges in the design of small-molecule inhibitors as antimalarial drugs targeting the inhibition of various malarial proteases.
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Affiliation(s)
- Kuldeep K Roy
- National Institute of Pharmaceutical Education and Research (NIPER), 4 Raja S.C. Mullick Road, Jadavpur, Kolkata 700032, West Bengal, India.
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21
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Waldecker M, Dasanna AK, Lansche C, Linke M, Srismith S, Cyrklaff M, Sanchez CP, Schwarz US, Lanzer M. Differential time-dependent volumetric and surface area changes and delayed induction of new permeation pathways in P. falciparum-infected hemoglobinopathic erythrocytes. Cell Microbiol 2016; 19. [PMID: 27450804 PMCID: PMC5298026 DOI: 10.1111/cmi.12650] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 07/01/2016] [Accepted: 07/15/2016] [Indexed: 12/31/2022]
Abstract
During intraerythrocytic development, Plasmodium falciparum increases the ion permeability of the erythrocyte plasma membrane to an extent that jeopardizes the osmotic stability of the host cell. A previously formulated numeric model has suggested that the parasite prevents premature rupture of the host cell by consuming hemoglobin (Hb) in excess of its own anabolic needs. Here, we have tested the colloid‐osmotic model on the grounds of time‐resolved experimental measurements on cell surface area and volume. We have further verified whether the colloid‐osmotic model can predict time‐dependent volumetric changes when parasites are grown in erythrocytes containing the hemoglobin variants S or C. A good agreement between model‐predicted and empirical data on both infected erythrocyte and intracellular parasite volume was found for parasitized HbAA and HbAC erythrocytes. However, a delayed induction of the new permeation pathways needed to be taken into consideration for the latter case. For parasitized HbAS erythrocyte, volumes diverged from model predictions, and infected erythrocytes showed excessive vesiculation during the replication cycle. We conclude that the colloid‐osmotic model provides a plausible and experimentally supported explanation of the volume expansion and osmotic stability of P. falciparum‐infected erythrocytes. The contribution of vesiculation to the malaria‐protective function of hemoglobin S is discussed.
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Affiliation(s)
- Mailin Waldecker
- Department of Infectious Diseases, Parasitology, Heidelberg University, Medical School, Im Neuenheimer Feld 324, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Anil K Dasanna
- BioQuant, Heidelberg University, Im Neuenheimer Feld 267, Heidelberg, 69120, Baden-Württemberg, Germany.,Institute for Theoretical Physics, Heidelberg University, Philosophenweg 19, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Christine Lansche
- Department of Infectious Diseases, Parasitology, Heidelberg University, Medical School, Im Neuenheimer Feld 324, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Marco Linke
- BioQuant, Heidelberg University, Im Neuenheimer Feld 267, Heidelberg, 69120, Baden-Württemberg, Germany.,Institute for Theoretical Physics, Heidelberg University, Philosophenweg 19, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Sirikamol Srismith
- Department of Infectious Diseases, Parasitology, Heidelberg University, Medical School, Im Neuenheimer Feld 324, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Marek Cyrklaff
- Department of Infectious Diseases, Parasitology, Heidelberg University, Medical School, Im Neuenheimer Feld 324, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Cecilia P Sanchez
- Department of Infectious Diseases, Parasitology, Heidelberg University, Medical School, Im Neuenheimer Feld 324, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Ulrich S Schwarz
- BioQuant, Heidelberg University, Im Neuenheimer Feld 267, Heidelberg, 69120, Baden-Württemberg, Germany.,Institute for Theoretical Physics, Heidelberg University, Philosophenweg 19, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Michael Lanzer
- Department of Infectious Diseases, Parasitology, Heidelberg University, Medical School, Im Neuenheimer Feld 324, Heidelberg, 69120, Baden-Württemberg, Germany
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Abstract
Some hours after invading the erythrocytes of its human host, the malaria parasite Plasmodium falciparum induces an increase in the permeability of the erythrocyte membrane to monovalent ions. The resulting net influx of Na(+) and net efflux of K(+), down their respective concentration gradients, converts the erythrocyte cytosol from an initially high-K(+), low-Na(+) solution to a high-Na(+), low-K(+) solution. The intraerythrocytic parasite itself exerts tight control over its internal Na(+), K(+), Cl(-), and Ca(2+) concentrations and its intracellular pH through the combined actions of a range of membrane transport proteins. The molecular mechanisms underpinning ion regulation in the parasite are receiving increasing attention, not least because PfATP4, a P-type ATPase postulated to be involved in Na(+) regulation, has emerged as a potential antimalarial drug target, susceptible to inhibition by a wide range of chemically unrelated compounds.
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Affiliation(s)
- Kiaran Kirk
- Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia;
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23
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Abstract
Food fortified with folic acid has been available for consumption in North America for over a decade. This strategy has led to an increase in folate levels in the general population and, more importantly, a significant decrease in the incidence of neural tube defects. However, this increase in folate intake has been associated with a greater risk of cancer disease. Many African countries are now embracing this concept; however, because folate promotes malaria parasite division, as it does in cancer cells, there is a possibility of malaria exacerbation if folate intake is increased. A precedent for such a concern is the now compelling evidence showing that an increase in iron intake can lead to a higher malaria risk; as a result, mass administration of iron in malaria-endemic areas is not recommended. In this article, we review work on the effect of folate on malaria parasites. Although this topic has received little research attention, the available data suggest that the increase in folate concentration could be associated with an increase in malaria infection. Thus, the introduction of food fortification with folic acid in malaria-endemic areas should be attended by precautionary programs to monitor the risk of malaria.
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Affiliation(s)
- Alexis Nzila
- Department of Life Sciences, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia
| | - John Okombo
- University of Cape Town, Cape Town, South Africa
| | - John Hyde
- Manchester Institute of Biotechnology (MIB), Manchester, United Kingdom
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Screening for Drugs Against the Plasmodium falciparum Digestive Vacuole by Imaging Flow Cytometry. Methods Mol Biol 2016; 1389:195-205. [PMID: 27460247 DOI: 10.1007/978-1-4939-3302-0_14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Phenotypic assays are increasingly employed to provide clues about drug mechanisms. In antimalarial drug screening, however, the majority of assays are designed to only measure parasite-killing activity. We describe here a high-content assay to detect drug-mediated perturbation of the digestive vacuole integrity in the trophozoite stage of Plasmodium falciparum, using the ImageStream imaging flow cytometer.
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25
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Bennett HM, Mok HP, Gkrania-Klotsas E, Tsai IJ, Stanley EJ, Antoun NM, Coghlan A, Harsha B, Traini A, Ribeiro DM, Steinbiss S, Lucas SB, Allinson KSJ, Price SJ, Santarius TS, Carmichael AJ, Chiodini PL, Holroyd N, Dean AF, Berriman M. The genome of the sparganosis tapeworm Spirometra erinaceieuropaei isolated from the biopsy of a migrating brain lesion. Genome Biol 2015. [PMID: 25413302 PMCID: PMC4265353 DOI: 10.1186/s13059-014-0510-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Sparganosis is an infection with a larval Diphyllobothriidea tapeworm. From a rare cerebral case presented at a clinic in the UK, DNA was recovered from a biopsy sample and used to determine the causative species as Spirometra erinaceieuropaei through sequencing of the cox1 gene. From the same DNA, we have produced a draft genome, the first of its kind for this species, and used it to perform a comparative genomics analysis and to investigate known and potential tapeworm drug targets in this tapeworm. RESULTS The 1.26 Gb draft genome of S. erinaceieuropaei is currently the largest reported for any flatworm. Through investigation of β-tubulin genes, we predict that S. erinaceieuropaei larvae are insensitive to the tapeworm drug albendazole. We find that many putative tapeworm drug targets are also present in S. erinaceieuropaei, allowing possible cross application of new drugs. In comparison to other sequenced tapeworm species we observe expansion of protease classes, and of Kuntiz-type protease inhibitors. Expanded gene families in this tapeworm also include those that are involved in processes that add post-translational diversity to the protein landscape, intracellular transport, transcriptional regulation and detoxification. CONCLUSIONS The S. erinaceieuropaei genome begins to give us insight into an order of tapeworms previously uncharacterized at the genome-wide level. From a single clinical case we have begun to sketch a picture of the characteristics of these organisms. Finally, our work represents a significant technological achievement as we present a draft genome sequence of a rare tapeworm, and from a small amount of starting material.
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The Apicomplexan CDC/MACPF-like pore-forming proteins. Curr Opin Microbiol 2015; 26:48-52. [PMID: 26025132 DOI: 10.1016/j.mib.2015.05.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 05/01/2015] [Accepted: 05/06/2015] [Indexed: 11/22/2022]
Abstract
Pore-forming proteins (PFPs) encompass a broad family of proteins that are used for virulence or immune defense. Members of the cholesterol-dependent cytolysins (CDCs) and membrane attack complex/perforin (MACPF) family of PFPs form large β-barrel pores in the membrane. The CDC/MACPF proteins contain a characteristic four-stranded β-sheet that is flanked by two α-helical bundles, which unfold to form two transmembrane β-hairpins. Apicomplexan eukaryotic parasites express CDC/MACPFs termed perforin-like proteins (PLPs). Here we review recent studies that provide key insights into the assembly and regulation of the Apicomplexan PLP (ApiMACPF) molecular pore-forming mechanisms, which are necessary for the osmotically driven rupture of the parasitophorous vacuole and host cell membrane, and cell traversal by these parasites.
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Exploiting the coenzyme A biosynthesis pathway for the identification of new antimalarial agents: the case for pantothenamides. Biochem Soc Trans 2015; 42:1087-93. [PMID: 25110007 DOI: 10.1042/bst20140158] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Malaria kills more than half a million people each year. There is no vaccine, and recent reports suggest that resistance is developing to the antimalarial regimes currently recommended by the World Health Organization. New drugs are therefore needed to ensure malaria treatment options continue to be available. The intra-erythrocytic stage of the malaria parasite's life cycle is dependent on an extracellular supply of pantothenate (vitamin B5), the precursor of CoA (coenzyme A). It has been known for many years that proliferation of the parasite during this stage of its life cycle can be inhibited with pantothenate analogues. We have shown recently that pantothenamides, a class of pantothenate analogues with antibacterial activity, inhibit parasite proliferation at submicromolar concentrations and do so competitively with pantothenate. These compounds, however, are degraded, and therefore rendered inactive, by the enzyme pantetheinase (vanin), which is present in serum. In the present mini-review, we discuss the two strategies that have been put forward to overcome pantetheinase-mediated degradation of pantothenamides. The strategies effectively provide an opportunity for pantothenamides to be tested in vivo. We also put forward our 'blueprint' for the further development of pantothenamides (and other pantothenate analogues) as potential antimalarials.
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Abstract
Although efforts to understand the basis for inter-strain phenotypic variation in the most virulent malaria species, Plasmodium falciparum, have benefited from advances in genomic technologies, there have to date been few metabolomic studies of this parasite. Using 1H-NMR spectroscopy, we have compared the metabolite profiles of red blood cells infected with different P. falciparum strains. These included both chloroquine-sensitive and chloroquine-resistant strains, as well as transfectant lines engineered to express different isoforms of the chloroquine-resistance-conferring pfcrt (P. falciparum chloroquine resistance transporter). Our analyses revealed strain-specific differences in a range of metabolites. There was marked variation in the levels of the membrane precursors choline and phosphocholine, with some strains having >30-fold higher choline levels and >5-fold higher phosphocholine levels than others. Chloroquine-resistant strains showed elevated levels of a number of amino acids relative to chloroquine-sensitive strains, including an approximately 2-fold increase in aspartate levels. The elevation in amino acid levels was attributable to mutations in pfcrt. Pfcrt-linked differences in amino acid abundance were confirmed using alternate extraction and detection (HPLC) methods. Mutations acquired to withstand chloroquine exposure therefore give rise to significant biochemical alterations in the parasite. The metabolite profiles of red blood cells infected with different malaria parasite strains were compared. Amino acid profiles varied with the chloroquine resistance status of the strain, and this was linked specifically to mutations in the parasite's chloroquine resistance transporter.
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Mistry SN, Drinkwater N, Ruggeri C, Sivaraman KK, Loganathan S, Fletcher S, Drag M, Paiardini A, Avery VM, Scammells PJ, McGowan S. Two-Pronged Attack: Dual Inhibition of Plasmodium falciparum M1 and M17 Metalloaminopeptidases by a Novel Series of Hydroxamic Acid-Based Inhibitors. J Med Chem 2014; 57:9168-83. [DOI: 10.1021/jm501323a] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shailesh N. Mistry
- Medicinal
Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Nyssa Drinkwater
- Department
of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Chiara Ruggeri
- Department
of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
- Dipartmento
di Scienze Biochimiche “A. Rossi Fanelli”, Sapienza Universita di Roma, 00185 Roma, Italy
| | - Komagal Kannan Sivaraman
- Department
of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Sasdekumar Loganathan
- Discovery
Biology, Eskitis Institute for Drug Discovery, Griffith University, Nathan, Queensland 4111, Australia
| | - Sabine Fletcher
- Discovery
Biology, Eskitis Institute for Drug Discovery, Griffith University, Nathan, Queensland 4111, Australia
| | - Marcin Drag
- Division
of Bioorganic Chemistry, Faculty of Chemistry, Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw, Poland
| | - Alessandro Paiardini
- Dipartmento
di Scienze Biochimiche “A. Rossi Fanelli”, Sapienza Universita di Roma, 00185 Roma, Italy
| | - Vicky M. Avery
- Discovery
Biology, Eskitis Institute for Drug Discovery, Griffith University, Nathan, Queensland 4111, Australia
| | - Peter J. Scammells
- Medicinal
Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Sheena McGowan
- Department
of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
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Spicer T, Fernandez-Vega V, Chase P, Scampavia L, To J, Dalton JP, Da Silva FL, Skinner-Adams TS, Gardiner DL, Trenholme KR, Brown CL, Ghosh P, Porubsky P, Wang JL, Whipple DA, Schoenen FJ, Hodder P. Identification of Potent and Selective Inhibitors of the Plasmodium falciparum M18 Aspartyl Aminopeptidase (PfM18AAP) of Human Malaria via High-Throughput Screening. ACTA ACUST UNITED AC 2014; 19:1107-15. [PMID: 24619116 DOI: 10.1177/1087057114525852] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 02/04/2014] [Indexed: 11/16/2022]
Abstract
The target of this study, the PfM18 aspartyl aminopeptidase (PfM18AAP), is the only AAP present in the genome of the malaria parasite Plasmodium falciparum. PfM18AAP is a metallo-exopeptidase that exclusively cleaves N-terminal acidic amino acids glutamate and aspartate. It is expressed in parasite cytoplasm and may function in concert with other aminopeptidases in protein degradation, of, for example, hemoglobin. Previous antisense knockdown experiments identified a lethal phenotype associated with PfM18AAP, suggesting that it is a valid target for new antimalaria therapies. To identify inhibitors of PfM18AAP function, a fluorescence enzymatic assay was developed using recombinant PfM18AAP enzyme and a fluorogenic peptide substrate (H-Glu-NHMec). This was screened against the Molecular Libraries Probe Production Centers Network collection of ~292,000 compounds (the Molecular Libraries Small Molecule Repository). A cathepsin L1 (CTSL1) enzyme-based assay was developed and used as a counter screen to identify compounds with nonspecific activity. Enzymology and phenotypic assays were used to determine mechanism of action and efficacy of selective and potent compounds identified from high-throughput screening. Two structurally related compounds, CID 6852389 and CID 23724194, yielded micromolar potency and were inactive in CTSL1 titration experiments (IC50>59.6 µM). As measured by the K(i) assay, both compounds demonstrated micromolar noncompetitive inhibition in the PfM18AAP enzyme assay. Both CID 6852389 and CID 23724194 demonstrated potency in malaria growth assays (IC504 µM and 1.3 µM, respectively).
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Affiliation(s)
- Timothy Spicer
- The Scripps Research Institute Molecular Screening Center, Scripps Florida, Jupiter, FL, USA
| | - Virneliz Fernandez-Vega
- The Scripps Research Institute Molecular Screening Center, Scripps Florida, Jupiter, FL, USA
| | - Peter Chase
- The Scripps Research Institute Molecular Screening Center, Scripps Florida, Jupiter, FL, USA
| | - Louis Scampavia
- The Scripps Research Institute Molecular Screening Center, Scripps Florida, Jupiter, FL, USA
| | - Joyce To
- Institute for Biotechnology of Infectious Diseases, University of Technology Sydney, Sydney, Australia
| | - John P Dalton
- Institute for Biotechnology of Infectious Diseases, University of Technology Sydney, Sydney, Australia Institute of Parasitology, McGill University, Quebec, Canada
| | - Fabio L Da Silva
- Malaria Biology Laboratory, The Queensland Institute of Medical Research, Brisbane, Australia
| | - Tina S Skinner-Adams
- Malaria Biology Laboratory, The Queensland Institute of Medical Research, Brisbane, Australia
| | - Donald L Gardiner
- Malaria Biology Laboratory, The Queensland Institute of Medical Research, Brisbane, Australia
| | - Katharine R Trenholme
- Malaria Biology Laboratory, The Queensland Institute of Medical Research, Brisbane, Australia
| | - Christopher L Brown
- School of Biomolecular and Physical Sciences, Griffith University, Brisbane, Australia
| | - Partha Ghosh
- The University of Kansas Specialized Chemistry Center, Lawrence, KS, USA
| | - Patrick Porubsky
- The University of Kansas Specialized Chemistry Center, Lawrence, KS, USA
| | - Jenna L Wang
- The University of Kansas Specialized Chemistry Center, Lawrence, KS, USA
| | - David A Whipple
- The University of Kansas Specialized Chemistry Center, Lawrence, KS, USA
| | - Frank J Schoenen
- The University of Kansas Specialized Chemistry Center, Lawrence, KS, USA
| | - Peter Hodder
- The Scripps Research Institute Molecular Screening Center, Scripps Florida, Jupiter, FL, USA
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Abstract
As it grows and replicates within the erythrocytes of its host the malaria parasite takes up nutrients from the extracellular medium, exports metabolites and maintains a tight control over its internal ionic composition. These functions are achieved via membrane transport proteins, integral membrane proteins that mediate the passage of solutes across the various membranes that separate the biochemical machinery of the parasite from the extracellular environment. Proteins of this type play a key role in antimalarial drug resistance, as well as being candidate drug targets in their own right. This review provides an overview of recent work on the membrane transport biology of the malaria parasite-infected erythrocyte, encompassing both the parasite-induced changes in the membrane transport properties of the host erythrocyte and the cell physiology of the intracellular parasite itself.
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32
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Isah MB, Ibrahim MA. The role of antioxidants treatment on the pathogenesis of malarial infections: a review. Parasitol Res 2014; 113:801-9. [PMID: 24525759 DOI: 10.1007/s00436-014-3804-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 01/28/2014] [Indexed: 11/28/2022]
Abstract
Oxidative damage is one of the most important pathological consequences of malarial infections. It affects vital organs of the body manifesting in changes such as splenomegaly, hepatomegaly, endothelial and cognitive damages. The currently used antimalarials often leave traces of these damages after therapy, as evident in memory impairment after cerebral malaria. Hence, some research investigations have focused attention on the use of antioxidants, alone or in combination with antimalarials, as a viable therapeutic strategy aimed at alleviating plasmodium-induced oxidative stress and its associated complications. However, the practical application of this approach often yields conflicting outcomes because some antimalarials specifically act via induction of oxidative stress. This article critically reviews most of the studies conducted on the potential role of antioxidant therapy in malarial infections. The most frequently investigated antioxidants are vitamins C and E, N-acetylcystein, folate and desferroxamine. Some of the investigations measured the effects of direct administration of the antioxidants on the plasmodium parasites while others performed an adjunctive therapy with standard antimalarials. The therapeutic application of each of the antioxidants in malaria management depends on the targeted aspect of malarial pathology. It is hoped that this article will provide an informed basis for future research activities on the therapeutic role of antioxidants on malarial pathogenesis.
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Bennett HM, Mok HP, Gkrania-Klotsas E, Tsai IJ, Stanley EJ, Antoun NM, Coghlan A, Harsha B, Traini A, Ribeiro DM, Steinbiss S, Lucas SB, Allinson KSJ, Price SJ, Santarius TS, Carmichael AJ, Chiodini PL, Holroyd N, Dean AF, Berriman M. The genome of the sparganosis tapeworm Spirometra erinaceieuropaei isolated from the biopsy of a migrating brain lesion. Genome Biol 2014; 15:510. [PMID: 25413302 PMCID: PMC4265353 DOI: 10.1186/preaccept-2413673241432389] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 10/28/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Sparganosis is an infection with a larval Diphyllobothriidea tapeworm. From a rare cerebral case presented at a clinic in the UK, DNA was recovered from a biopsy sample and used to determine the causative species as Spirometra erinaceieuropaei through sequencing of the cox1 gene. From the same DNA, we have produced a draft genome, the first of its kind for this species, and used it to perform a comparative genomics analysis and to investigate known and potential tapeworm drug targets in this tapeworm. RESULTS The 1.26 Gb draft genome of S. erinaceieuropaei is currently the largest reported for any flatworm. Through investigation of β-tubulin genes, we predict that S. erinaceieuropaei larvae are insensitive to the tapeworm drug albendazole. We find that many putative tapeworm drug targets are also present in S. erinaceieuropaei, allowing possible cross application of new drugs. In comparison to other sequenced tapeworm species we observe expansion of protease classes, and of Kuntiz-type protease inhibitors. Expanded gene families in this tapeworm also include those that are involved in processes that add post-translational diversity to the protein landscape, intracellular transport, transcriptional regulation and detoxification. CONCLUSIONS The S. erinaceieuropaei genome begins to give us insight into an order of tapeworms previously uncharacterized at the genome-wide level. From a single clinical case we have begun to sketch a picture of the characteristics of these organisms. Finally, our work represents a significant technological achievement as we present a draft genome sequence of a rare tapeworm, and from a small amount of starting material.
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Affiliation(s)
- Hayley M Bennett
- />Wellcome Trust Sanger Institute, Parasite Genomics, Cambridge, CB10 1SA UK
| | - Hoi Ping Mok
- />Department of Infectious Diseases, Addenbrooke’s NHS Trust, Cambridge, CB2 0QQ UK
| | | | - Isheng J Tsai
- />Wellcome Trust Sanger Institute, Parasite Genomics, Cambridge, CB10 1SA UK
- />Biodiversity Research Center, Academia Sinica, Taipei, 11529 Taiwan
| | - Eleanor J Stanley
- />Wellcome Trust Sanger Institute, Parasite Genomics, Cambridge, CB10 1SA UK
- />Eagle Genomics, Babraham Research Campus, Babraham, Cambridge, CB22 3AT UK
| | - Nagui M Antoun
- />Department of Radiology, Addenbrookes’s NHS Trust, Cambridge, CB2 0QQ UK
| | - Avril Coghlan
- />Wellcome Trust Sanger Institute, Parasite Genomics, Cambridge, CB10 1SA UK
| | - Bhavana Harsha
- />Wellcome Trust Sanger Institute, Parasite Genomics, Cambridge, CB10 1SA UK
| | - Alessandra Traini
- />Wellcome Trust Sanger Institute, Parasite Genomics, Cambridge, CB10 1SA UK
| | - Diogo M Ribeiro
- />Wellcome Trust Sanger Institute, Parasite Genomics, Cambridge, CB10 1SA UK
| | - Sascha Steinbiss
- />Wellcome Trust Sanger Institute, Parasite Genomics, Cambridge, CB10 1SA UK
| | - Sebastian B Lucas
- />Department of Histopathology, St Thomas’s Hospital, London, SE1 UK
| | - Kieren SJ Allinson
- />Department of Histopathology Section, Addenbrookes’s NHS Trust, Cambridge, CB2 0QQ UK
| | - Stephen J Price
- />Department of Neurosurgery, Addenbrookes’s NHS Trust, Cambridge, CB2 0QQ UK
| | - Thomas S Santarius
- />Department of Neurosurgery, Addenbrookes’s NHS Trust, Cambridge, CB2 0QQ UK
| | - Andrew J Carmichael
- />Department of Infectious Diseases, Addenbrooke’s NHS Trust, Cambridge, CB2 0QQ UK
| | - Peter L Chiodini
- />Hospital for Tropical Diseases and London School of Hygiene and Tropical Medicine, London, WC1E 6JD UK
| | - Nancy Holroyd
- />Wellcome Trust Sanger Institute, Parasite Genomics, Cambridge, CB10 1SA UK
| | - Andrew F Dean
- />Department of Histopathology Section, Addenbrookes’s NHS Trust, Cambridge, CB2 0QQ UK
| | - Matthew Berriman
- />Wellcome Trust Sanger Institute, Parasite Genomics, Cambridge, CB10 1SA UK
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Melo PM, Bagnaresi P, Paschoalin T, Hirata IY, Gazarini ML, Carmona AK. Plasmodium falciparum proteases hydrolyze plasminogen, generating angiostatin-like fragments. Mol Biochem Parasitol 2014; 193:45-54. [DOI: 10.1016/j.molbiopara.2014.01.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 01/22/2014] [Accepted: 01/25/2014] [Indexed: 12/27/2022]
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35
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Pillai AD, Nguitragool W, Lyko B, Dolinta K, Butler MM, Nguyen ST, Peet NP, Bowlin TL, Desai SA. Solute restriction reveals an essential role for clag3-associated channels in malaria parasite nutrient acquisition. Mol Pharmacol 2012; 82:1104-14. [PMID: 22949525 PMCID: PMC3502622 DOI: 10.1124/mol.112.081224] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 09/04/2012] [Indexed: 11/22/2022] Open
Abstract
The plasmodial surface anion channel (PSAC) increases erythrocyte permeability to many solutes in malaria but has uncertain physiological significance. We used a PSAC inhibitor with different efficacies against channels from two Plasmodium falciparum parasite lines and found concordant effects on transport and in vitro parasite growth when external nutrient concentrations were reduced. Linkage analysis using this growth inhibition phenotype in the Dd2 × HB3 genetic cross mapped the clag3 genomic locus, consistent with a role for two clag3 genes in PSAC-mediated transport. Altered inhibitor efficacy, achieved through allelic exchange or expression switching between the clag3 genes, indicated that the inhibitor kills parasites through direct action on PSAC. In a parasite unable to undergo expression switching, the inhibitor selected for ectopic homologous recombination between the clag3 genes to increase the diversity of available channel isoforms. Broad-spectrum inhibitors, which presumably interact with conserved sites on the channel, also exhibited improved efficacy with nutrient restriction. These findings indicate that PSAC functions in nutrient acquisition for intracellular parasites. Although key questions regarding the channel and its biological role remain, antimalarial drug development targeting PSAC should be pursued.
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Affiliation(s)
- Ajay D Pillai
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
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36
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The antioxidative effect of de novo generated vitamin B6 in Plasmodium falciparum validated by protein interference. Biochem J 2012; 443:397-405. [PMID: 22242896 DOI: 10.1042/bj20111542] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The malaria parasite Plasmodium falciparum is able to synthesize de novo PLP (pyridoxal 5'-phosphate), the active form of vitamin B6. In the present study, we have shown that the de novo synthesized PLP is used by the parasite to detoxify 1O2 (singlet molecular oxygen), a highly destructive reactive oxygen species arising from haemoglobin digestion. The formation of 1O2 and the response of the parasite were monitored by live-cell fluorescence microscopy, by transcription analysis and by determination of PLP levels in the parasite. Pull-down experiments of transgenic parasites overexpressing the vitamin B6-biosynthetic enzymes PfPdx1 and PfPdx2 clearly demonstrated an interaction of the two proteins in vivo which results in an elevated PLP level from 12.5 μM in wild-type parasites to 36.6 μM in the PfPdx1/PfPdx2-overexpressing cells and thus to a higher tolerance towards 1O2. In contrast, by applying the dominant-negative effect on the cellular level using inactive mutants of PfPdx1 and PfPdx2, P. falciparum becomes susceptible to 1O2. Our results demonstrate clearly the crucial role of vitamin B6 biosynthesis in the detoxification of 1O2 in P. falciparum. Besides the known role of PLP as a cofactor of many essential enzymes, this second important task of the vitamin B6 de novo synthesis as antioxidant emphasizes the high potential of this pathway as a target of new anti-malarial drugs.
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Purinoceptor signaling in malaria-infected erythrocytes. Microbes Infect 2012; 14:779-86. [PMID: 22580091 DOI: 10.1016/j.micinf.2012.04.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2012] [Revised: 04/13/2012] [Accepted: 04/13/2012] [Indexed: 01/25/2023]
Abstract
Human erythrocytes are endowed with ATP release pathways and metabotropic and ionotropic purinoceptors. This review summarizes the pivotal function of purinergic signaling in erythrocyte control of vascular tone, in hemolytic septicemia, and in malaria. In malaria, the intraerythrocytic parasite exploits the purinergic signaling of its host to adapt the erythrocyte to its requirements.
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The aminopeptidase inhibitor CHR-2863 is an orally bioavailable inhibitor of murine malaria. Antimicrob Agents Chemother 2012; 56:3244-9. [PMID: 22450967 DOI: 10.1128/aac.06245-11] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Malaria remains a significant risk in many areas of the world, with resistance to the current antimalarial pharmacopeia an ever-increasing problem. The M1 alanine aminopeptidase (PfM1AAP) and M17 leucine aminopeptidase (PfM17LAP) are believed to play a role in the terminal stages of digestion of host hemoglobin and thereby generate a pool of free amino acids that are essential for parasite growth and development. Here, we show that an orally bioavailable aminopeptidase inhibitor, CHR-2863, is efficacious against murine malaria.
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Poreba M, McGowan S, Skinner-Adams TS, Trenholme KR, Gardiner DL, Whisstock JC, To J, Salvesen GS, Dalton JP, Drag M. Fingerprinting the substrate specificity of M1 and M17 aminopeptidases of human malaria, Plasmodium falciparum. PLoS One 2012; 7:e31938. [PMID: 22359643 PMCID: PMC3281095 DOI: 10.1371/journal.pone.0031938] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Accepted: 01/18/2012] [Indexed: 11/22/2022] Open
Abstract
Background Plasmodium falciparum, the causative agent of human malaria, expresses two aminopeptidases, PfM1AAP and PfM17LAP, critical to generating a free amino acid pool used by the intraerythrocytic stage of the parasite for proteins synthesis, growth and development. These exopeptidases are potential targets for the development of a new class of anti-malaria drugs. Methodology/Principal Findings To define the substrate specificity of recombinant forms of these two malaria aminopeptidases we used a new library consisting of 61 fluorogenic substrates derived both from natural and unnatural amino acids. We obtained a detailed substrate fingerprint for recombinant forms of the enzymes revealing that PfM1AAP exhibits a very broad substrate tolerance, capable of efficiently hydrolyzing neutral and basic amino acids, while PfM17LAP has narrower substrate specificity and preferentially cleaves bulky, hydrophobic amino acids. The substrate library was also exploited to profile the activity of the native aminopeptidases in soluble cell lysates of P. falciparum malaria. Conclusions/Significance This data showed that PfM1AAP and PfM17LAP are responsible for majority of the aminopeptidase activity in these extracts. These studies provide specific substrate and mechanistic information important for understanding the function of these aminopeptidases and could be exploited in the design of new inhibitors to specifically target these for anti-malaria treatment.
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Affiliation(s)
- Marcin Poreba
- Division of Medicinal Chemistry and Microbiology, Faculty of Chemistry, Wroclaw University of Technology, Wroclaw, Poland
| | - Sheena McGowan
- Department of Biochemistry and Molecular Biology and Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, Victoria, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Tina S. Skinner-Adams
- Malaria Biology Laboratory, Queensland Institute of Medical Research, Brisbane, Queensland, Australia
- Griffith Medical Research College, Joint Program of Griffith University and the Queensland Institute of Medical Research, Brisbane, Queensland, Australia
- School of Medicine, The University of Queensland, Royal Brisbane Hospital, Brisbane, Queensland, Australia
| | - Katharine R. Trenholme
- Malaria Biology Laboratory, Queensland Institute of Medical Research, Brisbane, Queensland, Australia
- Griffith Medical Research College, Joint Program of Griffith University and the Queensland Institute of Medical Research, Brisbane, Queensland, Australia
- School of Medicine, The University of Queensland, Royal Brisbane Hospital, Brisbane, Queensland, Australia
| | - Donald L. Gardiner
- Malaria Biology Laboratory, Queensland Institute of Medical Research, Brisbane, Queensland, Australia
- Griffith Medical Research College, Joint Program of Griffith University and the Queensland Institute of Medical Research, Brisbane, Queensland, Australia
- School of Medicine, The University of Queensland, Royal Brisbane Hospital, Brisbane, Queensland, Australia
| | - James C. Whisstock
- Department of Biochemistry and Molecular Biology and Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, Victoria, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Joyce To
- Institute of Parasitology, McGill University, Sainte Anne de Bellevue, Quebec, Canada
| | - Guy S. Salvesen
- Program in Apoptosis and Cell Death Research, Sanford Burnham Medical Research Institute, La Jolla, California, United States of America
| | - John P. Dalton
- Institute of Parasitology, McGill University, Sainte Anne de Bellevue, Quebec, Canada
- * E-mail: (JD); (MD)
| | - Marcin Drag
- Division of Medicinal Chemistry and Microbiology, Faculty of Chemistry, Wroclaw University of Technology, Wroclaw, Poland
- Program in Apoptosis and Cell Death Research, Sanford Burnham Medical Research Institute, La Jolla, California, United States of America
- * E-mail: (JD); (MD)
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Hanssen E, Knoechel C, Dearnley M, Dixon MW, Le Gros M, Larabell C, Tilley L. Soft X-ray microscopy analysis of cell volume and hemoglobin content in erythrocytes infected with asexual and sexual stages of Plasmodium falciparum. J Struct Biol 2012; 177:224-32. [DOI: 10.1016/j.jsb.2011.09.003] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 09/05/2011] [Accepted: 09/09/2011] [Indexed: 12/13/2022]
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Insights into the gene expression profile of uncultivable hemotrophic Mycoplasma suis during acute infection, obtained using proteome analysis. J Bacteriol 2012; 194:1505-14. [PMID: 22267506 DOI: 10.1128/jb.00002-12] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hemotrophic mycoplasmas, bacteria without cell walls whose niche is the erythrocytes of their hosts, have never been cultivated in vitro. Therefore, knowledge of their pathogenesis is fundamental. Mycoplasma suis infects pigs, causing either acute fatal hemolytic anemia or chronic low-grade anemia, growth retardation, and immune suppression. Recently, the complete genomes of two hemotrophic mycoplasma species, M. suis and M. haemofelis, were sequenced, offering new strategies for the analysis of their pathogenesis. In this study we implemented a proteomic approach to identify M. suis proteins during acute infection by using tandem mass spectrometry. Twenty-two percent of the predicted proteins encoded in M. suis strain KI_3806 were identified. These included nearly all encoded proteins of glycolysis and nucleotide metabolism. The proteins for lipid metabolism, however, were underrepresented. A high proportion of the detected proteins are involved in information storage and processing (72.6%). In addition, several proteins of different functionalities, i.e., posttranslational modification, membrane genesis, signal transduction, intracellular trafficking, inorganic ion transport, and defense mechanisms, were identified. In its reduced genome, M. suis harbors 65.3% (strain Illinois) and 65.9% (strain KI_3806) of the genes encode hypothetical proteins. Of these, only 6.3% were identified at the proteome level. All proteins identified in this study are present in both M. suis strains and are encoded in more highly conserved regions of the genome sequence. In conclusion, our proteome approach is a further step toward the elucidation of the pathogenesis and life cycle of M. suis as well as the establishment of an in vitro cultivation system.
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Millholland MG, Chandramohanadas R, Pizzarro A, Wehr A, Shi H, Darling C, Lim CT, Greenbaum DC. The malaria parasite progressively dismantles the host erythrocyte cytoskeleton for efficient egress. Mol Cell Proteomics 2011; 10:M111.010678. [PMID: 21903871 DOI: 10.1074/mcp.m111.010678] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Plasmodium falciparum is an obligate intracellular pathogen responsible for worldwide morbidity and mortality. This parasite establishes a parasitophorous vacuole within infected red blood cells wherein it differentiates into multiple daughter cells that must rupture their host cells to continue another infectious cycle. Using atomic force microscopy, we establish that progressive macrostructural changes occur to the host cell cytoskeleton during the last 15 h of the erythrocytic life cycle. We used a comparative proteomics approach to determine changes in the membrane proteome of infected red blood cells during the final steps of parasite development that lead to egress. Mass spectrometry-based analysis comparing the red blood cell membrane proteome in uninfected red blood cells to that of infected red blood cells and postrupture vesicles highlighted two temporally distinct events; (Hay, S. I., et al. (2009). A world malaria map: Plasmodium falciparum endemicity in 2007. PLoS Med. 6, e1000048) the striking loss of cytoskeletal adaptor proteins that are part of the junctional complex, including α/β-adducin and tropomyosin, correlating temporally with the emergence of large holes in the cytoskeleton seen by AFM as early ~35 h postinvasion, and (Maier, A. G., et al. (2008) Exported proteins required for virulence and rigidity of Plasmodium falciparum-infected human erythrocytes. Cell 134, 48-61) large-scale proteolysis of the cytoskeleton during rupture ~48 h postinvasion, mediated by host calpain-1. We thus propose a sequential mechanism whereby parasites first remove a selected set of cytoskeletal adaptor proteins to weaken the host membrane and then use host calpain-1 to dismantle the remaining cytoskeleton, leading to red blood cell membrane collapse and parasite release.
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Rawat M, Vijay S, Gupta Y, Dixit R, Tiwari PK, Sharma A. Sequence homology and structural analysis of plasmepsin 4 isolated from Indian Plasmodium vivax isolates. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2011; 11:924-933. [PMID: 21382523 DOI: 10.1016/j.meegid.2011.02.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Revised: 02/28/2011] [Accepted: 02/28/2011] [Indexed: 02/05/2023]
Abstract
Plasmodium vivax malaria is a globally widespread disease responsible for 50% of human malaria cases in Central and South America, South East Asia and Indian subcontinent. The rising severity of the disease and emerging resistance of the parasite has emphasized the need for the search of novel therapeutic targets to combat P. vivax malaria. Plasmepsin 4 (PM4) a food vacuole aspartic protease is essential in parasite functions and viability such as initiating hemoglobin digestion and processing of proteins and is being looked upon as potential drug target. Although the plasmepsins of Plasmodium falciparum have been extensively studied, the plasmepsins of P. vivax are not well characterized. This is the first report detailing complete PM4 gene analysis from Indian P. vivax isolates. Blast results of sequences of P. vivax plasmepsin 4 (PvPM4) shows 100% homology among isolates of P. vivax collected from different geographical regions of India. All of the seven Indian isolates did not contain intron within the coding region. Interestingly, PvPM4 sequence analysis showed a very high degree of homology with all other sequences of Plasmodium species available in the genebank. Our results strongly suggest that PvPM4 are highly conserved except a small number of amino acid substitutions that did not modify key motifs at active site formation for the function or the structure of the enzymes. Furthermore, our study shows that PvPM4 occupies unique phylogenetic status within Plasmodium group and sufficiently differ from the most closely related human aspartic protease, cathepsin D. The analysis of 3D model of PM4 showed a typical aspartic protease structure with bi-lobed, compact and distinct peptide binding cleft in both P. vivax and P. falciparum. In order to validate appropriate use of PM4 as potential anti-malarial drug target, studies on genetic and structural variations among P. vivax plasmepsins (PvPMs) from different geographical regions are of utmost importance for drugs and vaccine designs for anti-malarial strategies.
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Affiliation(s)
- Manmeet Rawat
- Protein Biochemistry and Structural Biology Laboratory, National Institute of Malaria Research, Sector-8, Dwarka, New Delhi, India
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Mauritz J, Seear R, Esposito A, Kaminski C, Skepper J, Warley A, Lew V, Tiffert T. X-ray microanalysis investigation of the changes in Na, K, and hemoglobin concentration in plasmodium falciparum-infected red blood cells. Biophys J 2011; 100:1438-45. [PMID: 21402025 PMCID: PMC3059598 DOI: 10.1016/j.bpj.2011.02.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 01/21/2011] [Accepted: 02/01/2011] [Indexed: 11/15/2022] Open
Abstract
Plasmodium falciparum is responsible for severe malaria. During the ∼48 h duration of its asexual reproduction cycle in human red blood cells, the parasite causes profound alterations in the homeostasis of the host red cell, with reversal of the normal Na and K gradients across the host cell membrane, and a drastic fall in hemoglobin content. A question critical to our understanding of how the host cell retains its integrity for the duration of the cycle had been previously addressed by modeling the homeostasis of infected cells. The model predicted a critical contribution of excess hemoglobin consumption to cell integrity (the colloidosmotic hypothesis). Here we tested this prediction with the use of electron-probe x-ray microanalysis to measure the stage-related changes in Na, K, and Fe contents in single infected red cells and in uninfected controls. The results document a decrease in Fe signal with increased Na/K ratio. Interpreted in terms of concentrations, the results point to a sustained fall in host cell hemoglobin concentration with parasite maturation, supporting a colloidosmotic role of excess hemoglobin digestion. The results also provide, for the first time to our knowledge, comprehensive maps of the elemental distributions of Na, K, and Fe in falciparum-infected red blood cells.
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Affiliation(s)
- Jakob M.A. Mauritz
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Rachel Seear
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Alessandro Esposito
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Clemens F. Kaminski
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
- School for Advanced Optical Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Jeremy N. Skepper
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Alice Warley
- Centre for Ultrastructural Imaging, King's College London, London, United Kingdom
| | - Virgilio L. Lew
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Teresa Tiffert
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
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Moon SU, Kang JM, Kim TS, Kong Y, Sohn WM, Na BK. Plasmodium vivax: collaborative roles for plasmepsin 4 and vivapains in hemoglobin hydrolysis. Exp Parasitol 2011; 128:127-32. [PMID: 21334328 DOI: 10.1016/j.exppara.2011.02.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 12/08/2010] [Accepted: 02/14/2011] [Indexed: 01/16/2023]
Abstract
Plasmepsins, a family of aspartic proteases of Plasmodium species, are known to participate in a wide variety of cellular processes essential for parasite survival. Therefore, the plasmepsins of malaria parasites have been recognized as attractive antimalarial drug targets. Although the plasmepsins of P. falciparum have been extensively characterized, the plasmepsins of P. vivax are currently not well known. To expand our understanding of the plasmepsins of P. vivax, we characterized plasmepsin 4 of P. vivax (PvPM4). The bacterially expressed recombinant PvPM4 was insoluble, but it was easily refolded into a soluble protein. The processing of PvPM4 into a mature enzyme occurred through autocatalytic activity under acidic conditions in a pepstatin A-sensitive manner, in which process a portion of prodomain was essential for correct folding. PvPM4 could hydrolyze native human hemoglobin at acidic pHs, but preferred denatured hemoglobin as a substrate. PvPM4 acted synergistically with vivapain-2 and vivapain-3, cysteine proteases of P. vivax, in the hydrolysis of hemoglobin. The vivapains also mediated processing of PvPM4 into a mature enzyme. These results collectively suggest that PvPM4 is an active hemoglobinase of P. vivax that works collaboratively with vivapains to enhance the parasite's ability to hydrolyze hemoglobin.
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Affiliation(s)
- Sung-Ung Moon
- Department of Parasitology, Brain Korea 21 Biomedical Center, and Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju 660-751, Republic of Korea
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Torrentino-Madamet M, Alméras L, Desplans J, Le Priol Y, Belghazi M, Pophillat M, Fourquet P, Jammes Y, Parzy D. Global response of Plasmodium falciparum to hyperoxia: a combined transcriptomic and proteomic approach. Malar J 2011; 10:4. [PMID: 21223545 PMCID: PMC3030542 DOI: 10.1186/1475-2875-10-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Accepted: 01/11/2011] [Indexed: 12/21/2022] Open
Abstract
Background Over its life cycle, the Plasmodium falciparum parasite is exposed to different environmental conditions, particularly to variations in O2 pressure. For example, the parasite circulates in human venous blood at 5% O2 pressure and in arterial blood, particularly in the lungs, at 13% O2 pressure. Moreover, the parasite is exposed to 21% O2 levels in the salivary glands of mosquitoes. Methods To study the metabolic adaptation of P. falciparum to different oxygen pressures during the intraerythrocytic cycle, a combined approach using transcriptomic and proteomic techniques was undertaken. Results Even though hyperoxia lengthens the parasitic cycle, significant transcriptional changes were detected in hyperoxic conditions in the late-ring stage. Using PS 6.0™ software (Ariadne Genomics) for microarray analysis, this study demonstrate up-expression of genes involved in antioxidant systems and down-expression of genes involved in the digestive vacuole metabolism and the glycolysis in favour of mitochondrial respiration. Proteomic analysis revealed increased levels of heat shock proteins, and decreased levels of glycolytic enzymes. Some of this regulation reflected post-transcriptional modifications during the hyperoxia response. Conclusions These results seem to indicate that hyperoxia activates antioxidant defence systems in parasites to preserve the integrity of its cellular structures. Moreover, environmental constraints seem to induce an energetic metabolism adaptation of P. falciparum. This study provides a better understanding of the adaptive capabilities of P. falciparum to environmental changes and may lead to the development of novel therapeutic targets.
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Affiliation(s)
- Marylin Torrentino-Madamet
- UMR-MD3 (Université de la Méditerranée), Antenne IRBA de Marseille (IMTSSA, Le Pharo), Allée du Médecin Colonel Eugène Jamot, BP 60109, 13262 Marseille cedex 07, France.
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Esposito A, Choimet JB, Skepper JN, Mauritz JMA, Lew VL, Kaminski CF, Tiffert T. Quantitative imaging of human red blood cells infected with Plasmodium falciparum. Biophys J 2010; 99:953-60. [PMID: 20682274 DOI: 10.1016/j.bpj.2010.04.065] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Revised: 04/14/2010] [Accepted: 04/20/2010] [Indexed: 11/24/2022] Open
Abstract
During its 48 h asexual reproduction cycle, the malaria parasite Plasmodium falciparum ingests and digests hemoglobin in excess of its metabolic requirements and causes major changes in the homeostasis of the host red blood cell (RBC). A numerical model suggested that this puzzling excess consumption of hemoglobin is necessary for the parasite to reduce the colloidosmotic pressure within the host RBC, thus preventing lysis before completion of its reproduction cycle. However, the validity of the colloidosmotic hypothesis appeared to be compromised by initial conflicts between model volume predictions and experimental observations. Here, we investigated volume and membrane area changes in infected RBCs (IRBCs) using fluorescence confocal microscopy on calcein-loaded RBCs. Substantial effort was devoted to developing and testing a new threshold-independent algorithm for the precise estimation of cell volumes and surface areas to overcome the shortfalls of traditional methods. We confirm that the volume of IRBCs remains almost constant during parasite maturation, suggesting that the reported increase in IRBCs' osmotic fragility results from a reduction in surface area and increased lytic propensity on volume expansion. These results support the general validity of the colloidosmotic hypothesis, settle the IRBC volume debate, and help to constrain the range of parameter values in the numerical model.
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Affiliation(s)
- Alessandro Esposito
- Department of Chemical Engineering, and Biotechnology, University of Cambridge, Cambridge, United Kingdom.
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Föller M, Bobbala D, Koka S, Boini KM, Mahmud H, Kasinathan RS, Shumilina E, Amann K, Beranek G, Sausbier U, Ruth P, Sausbier M, Lang F, Huber SM. Functional significance of the intermediate conductance Ca2+-activated K+ channel for the short-term survival of injured erythrocytes. Pflugers Arch 2010; 460:1029-44. [PMID: 20857305 DOI: 10.1007/s00424-010-0878-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Revised: 08/19/2010] [Accepted: 08/24/2010] [Indexed: 01/30/2023]
Abstract
Increased cytosolic Ca(2+) concentrations activate Gardos K(+) channels in human erythrocytes with membrane hyperpolarization, efflux of K(+), Cl⁻, and osmotically obliged H₂O resulting in cell shrinkage, a phenomenon referred to as Gardos effect. We tested whether the Gardos effect delays colloid osmotic hemolysis of injured erythrocytes from mice lacking the Ca(2+)-activated K(+) channel K(Ca)3.1. To this end, we applied patch clamp and flow cytometry and determined in vitro as well as in vivo hemolysis. As a result, erythrocytes from K(Ca)3.1-deficient (K(Ca)3.1(-/-)) mice lacked Gardos channel activity and the Gardos effect. Blood parameters, reticulocyte count, or osmotic erythrocyte resistance, however, did not differ between K(Ca)3.1(-/-) mice and their wild-type littermates, suggesting low or absent Gardos channel activity in unstressed erythrocytes. Oxidative stress-induced Ca(2+) entry and phospholipid scrambling were significantly less pronounced in K(Ca)3.1(-/-) than in wild-type erythrocytes. Moreover, in vitro treatment with α-toxin from Staphylococcus aureus, which forms pores in the cellular membrane, resulted in significantly stronger hemolysis of K(Ca)3.1(-/-) than of wild-type erythrocytes. Intravenous injection of α-toxin induced more profound hemolysis in K(Ca)3.1(-/-) than in wild-type mice. Similarly, intra-peritoneal application of the redox-active substance phenylhydrazine, an agent for the induction of hemolytic anemia, was followed by a significantly stronger decrease of hematocrit in K(Ca)3.1(-/-) than in wild-type mice. Finally, malaria infection triggered the activation of K(Ca)3.1 and transient shrinkage of the infected erythrocytes. In conclusion, K(Ca)3.1 channel activity and Gardos effect counteract hemolysis of injured erythrocytes, thus decreasing hemoglobin release into circulating blood.
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Affiliation(s)
- Michael Föller
- Department of Physiology, University of Tübingen, Tübingen, Germany
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Glushakova S, Humphrey G, Leikina E, Balaban A, Miller J, Zimmerberg J. New stages in the program of malaria parasite egress imaged in normal and sickle erythrocytes. Curr Biol 2010; 20:1117-21. [PMID: 20537541 PMCID: PMC3541015 DOI: 10.1016/j.cub.2010.04.051] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Revised: 04/09/2010] [Accepted: 04/21/2010] [Indexed: 10/19/2022]
Abstract
The apicomplexan parasite Plasmodium falciparum causes malignant malaria. The mechanism of parasite egress from infected erythrocytes that disseminate parasites in the host at the end of each asexual cycle is unknown. Two new stages of the egress program are revealed: (1) swelling of the parasitophorous vacuole accompanied by shrinkage of the erythrocyte compartment, and (2) poration of the host cell membrane seconds before erythrocyte rupture because of egress. Egress was inhibited in dehydrated cells from patients with sickle cell disease in accord with experimental dehydration of normal cells, suggesting that vacuole swelling involves intake of water from the erythrocyte compartment. Erythrocyte membrane poration occurs in relaxed cells, thus excluding involvement of osmotic pressure in this process. Poration does not depend on cysteine protease activity, because protease inhibition blocks egress but not poration, and poration is required for the parasite cycle because the membrane sealant P1107 interferes with egress. We suggest the following egress program: parasites initiate water influx into the vacuole from the erythrocyte cytosol to expand the vacuole for parasite separation and vacuole rupture upon its critical swelling. Separated parasites leave the erythrocyte by breaching its membrane, weakened by putative digestion of erythrocyte cytoskeleton and membrane poration.
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Affiliation(s)
- Svetlana Glushakova
- Program in Physical Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Glen Humphrey
- Program in Physical Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Evgenia Leikina
- Program in Physical Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Amanda Balaban
- Program in Physical Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jeffrey Miller
- National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892, USA
| | - Joshua Zimmerberg
- Program in Physical Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
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Downstream effects of haemoglobinase inhibition in Plasmodium falciparum-infected erythrocytes. Mol Biochem Parasitol 2010; 173:81-7. [PMID: 20478341 DOI: 10.1016/j.molbiopara.2010.05.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Revised: 04/28/2010] [Accepted: 05/08/2010] [Indexed: 12/22/2022]
Abstract
Blood-stage malarial parasites (Plasmodium falciparum) digest large quantities of host haemoglobin during their asexual development in erythrocytes. The haemoglobin digestion pathway, involving a succession of cleavages by various peptidases, appears to be essential for parasite development and has received much attention as an antimalarial drug target. A variety of peptidase inhibitors that have potent antimalarial activity are believed to inhibit and/or kill parasites by blocking haemoglobin digestion. It has not however been established how such a blockage might lead to parasite death. The answer to this question should lie in identifying the affected physiological function, but the purpose of excess haemoglobin digestion by P. falciparum has for many years been the subject of debate. The process was traditionally believed to be nutritional until Lew et al. [Blood 2003;101:4189-94] suggested that it is linked to volume control of the infected erythrocyte and is necessary to prevent premature osmotic lysis of the host cell. Their model predicts that sufficient inhibition of haemoglobin degradation should result in premature haemolysis. In this study we examined the downstream effects of reduced haemoglobin digestion on osmoprotection and nutrition. We found that inhibitors of haemoglobinases (plasmepsins, falcipains and aminopeptidases) did not cause premature haemolysis. The inhibitors did however block parasite development and this effect corresponded to a strong inhibition of protein synthesis. The effect on protein synthesis (i) occurred at inhibitor concentrations and times of exposure that were relevant to parasite growth inhibition, (ii) was observed with different chemical classes of inhibitor, and (iii) was synergistic when a plasmepsin and a falcipain inhibitor were combined, reflecting the well-established antimalarial synergism of the combination. Taken together, the results suggest that the likely primary downstream effect of inhibition of haemoglobin degradation is amino acid depletion, leading to blockade of protein synthesis, and that the parasite probably degrades globin for nutritional purposes.
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