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Bager Christensen I, Ribas L, Mosshammer M, Abrahamsen ML, Kühl M, Larsen S, Dela F, Gillberg L. Choice of medium affects PBMC quantification, cell size, and downstream respiratory analysis. Mitochondrion 2024; 77:101890. [PMID: 38718898 DOI: 10.1016/j.mito.2024.101890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 03/19/2024] [Accepted: 04/28/2024] [Indexed: 05/21/2024]
Abstract
High-resolution respirometry (HRR) can assess peripheral blood mononuclear cell (PBMC) bioenergetics, but no standardized medium for PBMC preparation and HRR analysis exist. Here, we study the effect of four different media (MiR05, PBS, RPMI, Plasmax) on the count, size, and HRR (Oxygraph-O2k) of intact PBMCs. Remarkably, the cell count was 21 % higher when PBMCs were resuspended in MiR05 than in PBS or Plasmax, causing O2 flux underestimation during HRR due to inherent adjustments. Moreover, smaller cell size and cell aggregation was observed in MiR05. Based on our findings, we propose that Plasmax, PBS or RPMI is more suitable than MiR05 for HRR of intact PBMCs. We provide oxygen solubility factors for Plasmax and PBS and encourage further optimization of a standardized HRR protocol for intact PBMCs.
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Affiliation(s)
- Ida Bager Christensen
- Xlab, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lucas Ribas
- Xlab, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Maria Mosshammer
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | - Michael Kühl
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Steen Larsen
- Xlab, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark; Clinical Research Centre, Medical University of Bialystok, Bialystok, Poland; Institute of Sports Medicine Copenhagen, Department of Orthopedic Surgery M, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Denmark
| | - Flemming Dela
- Xlab, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Geriatrics, Bispebjerg University Hospital, Copenhagen, Denmark
| | - Linn Gillberg
- Xlab, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark.
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Basco LK. Cultivation of Asexual Intraerythrocytic Stages of Plasmodium falciparum. Pathogens 2023; 12:900. [PMID: 37513747 PMCID: PMC10384318 DOI: 10.3390/pathogens12070900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 06/22/2023] [Accepted: 06/26/2023] [Indexed: 07/30/2023] Open
Abstract
Successfully developed in 1976, the continuous in vitro culture of Plasmodium falciparum has many applications in the field of malaria research. It has become an important experimental model that directly uses a human pathogen responsible for a high prevalence of morbidity and mortality in many parts of the world and is a major source of biological material for immunological, biochemical, molecular, and pharmacological studies. Until present, the basic techniques described by Trager and Jensen and Haynes et al. remain unchanged in many malaria research laboratories. Nonetheless, different factors, including culture media, buffers, serum substitutes and supplements, sources of erythrocytes, and conditions of incubation (especially oxygen concentration), have been modified by different investigators to adapt the original technique in their laboratories or enhance the in vitro growth of the parasites. The possible effects and benefits of these modifications for the continuous cultivation of asexual intraerythrocytic stages of P. falciparum, as well as future challenges in developing a serum-free cultivation system and axenic cultures, are discussed.
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Affiliation(s)
- Leonardo K Basco
- Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), Assistance Publique-Hôpitaux de Marseille (AP-HM), Service de Santé des Armées (SSA), Unité Mixte de Recherche (UMR) Vecteurs-Infections Tropicales et Méditerranéennes (VITROME), 13005 Marseille, France
- Institut Hospitalo-Universitaire-Méditerranée Infection, 19-21 Boulevard Jean Moulin, 13005 Marseille, France
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Nair S, Li X, Arya GA, McDew-White M, Ferrari M, Anderson T. Nutrient Limitation Magnifies Fitness Costs of Antimalarial Drug Resistance Mutations. Antimicrob Agents Chemother 2022; 66:e0152921. [PMID: 35465723 PMCID: PMC9112896 DOI: 10.1128/aac.01529-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 02/22/2022] [Indexed: 12/15/2022] Open
Abstract
Drug resistance mutations tend to disrupt key physiological processes and frequently carry fitness costs, which are a central determinant of the rate of spread of these mutations in natural populations. Head-to-head competition assays provide a standard approach to measuring fitness for malaria parasites. These assays typically use a standardized culture medium containing RPMI 1640, which has a 1.4- to 5.5-fold higher concentration of amino acids than human blood. In this rich medium, we predict that fitness costs will be underestimated because resource competition is weak. We tested this prediction using an artemisinin-sensitive parasite edited to contain kelch-C580Y or R561H mutations conferring resistance to artemisinin or synonymous control mutations. We examined the impact of these single amino acid mutations on fitness, using replicated head-to-head competition experiments conducted in media containing (i) normal RPMI, (ii) modified RPMI with reduced amino acid concentration, (iii) RPMI containing only isoleucine, or (iv) 3-fold diluted RPMI. We found a significant 1.3- to 1.4-fold increase in fitness costs measured in modified and isoleucine-only media relative to normal media, while fitness costs were 2.5-fold higher in diluted media. We conclude that fitness costs are strongly affected by media composition and will be significantly underestimated in normal RPMI. Several components differed between media, including pABA and sodium bicarbonate concentrations, so we cannot directly determine which is responsible. Elevated fitness costs in nature will limit spread of artemisinin (ART) resistance but will also promote evolution of compensatory mutations that restore fitness and can be exploited to maximize selection in laboratory experiments.
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Affiliation(s)
- Shalini Nair
- Disease Intervention and Prevention Program, Texas Biomedical Research Institute, San Antonio, Texas, USA
| | - Xue Li
- Disease Intervention and Prevention Program, Texas Biomedical Research Institute, San Antonio, Texas, USA
| | - Grace A. Arya
- Disease Intervention and Prevention Program, Texas Biomedical Research Institute, San Antonio, Texas, USA
| | - Marina McDew-White
- Disease Intervention and Prevention Program, Texas Biomedical Research Institute, San Antonio, Texas, USA
| | - Marco Ferrari
- Disease Intervention and Prevention Program, Texas Biomedical Research Institute, San Antonio, Texas, USA
| | - Tim Anderson
- Disease Intervention and Prevention Program, Texas Biomedical Research Institute, San Antonio, Texas, USA
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Continuous Cultures of Plasmodium Falciparum Established in Tanzania from Patients with Acute Malaria. Mediterr J Hematol Infect Dis 2021; 13:e2021036. [PMID: 34007424 PMCID: PMC8114889 DOI: 10.4084/mjhid.2021.036] [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: 02/11/2021] [Accepted: 04/16/2021] [Indexed: 11/28/2022] Open
Abstract
Background Malaria morbidity and mortality, almost entirely from Plasmodium falciparum, are still rampant in Africa: therefore, it is important to study the biology of the parasite and the parasite-host cell interactions. In vitro cultivation of Plasmodium falciparum is most useful for this purpose, as well as for investigating drug resistance and possible new therapies. Here we report that the Trager & Jensen continuous culture of P. falciparum can be established in a laboratory in Tanzania with minimal facilities and with modest expenditure. Methodology This was an in-vitro set up of continuous culture of Plasmodium falciparum study, carried out in 2016–2020 at Muhimbili university of health and allied sciences, Dar-es salaam. Parasite samples were obtained from patients with acute malaria, frozen parasites, and live cultures. Data was collected and analyzed using GraphPad Prism version 8. Results We have successfully achieved exponential growth of existing strains that are used worldwide, as well as of parasites in clinical samples from patients with acute malaria. In the aim to optimize growth we have compared human serum and bovine serum albumin as components of the culture media. Additionally, culture synchronization has been achieved using sorbitol. Conclusion This experimental system is now available to our institution and to researchers aiming at investigating drug sensitivity and mechanisms of protection against Plasmodium falciparum that accrue from various genes expressed in red cells.
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Hayakawa EH, Kato H, Nardone GA, Usukura J. A prospective mechanism and source of cholesterol uptake by Plasmodium falciparum-infected erythrocytes co-cultured with HepG2 cells. Parasitol Int 2020; 80:102179. [PMID: 32853776 DOI: 10.1016/j.parint.2020.102179] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 06/23/2020] [Accepted: 07/20/2020] [Indexed: 12/17/2022]
Abstract
Plasmodium falciparum (P. falciparum) parasites still cause lethal infections worldwide, especially in Africa (https://www.who.int/publications/i/item/world-malaria-report-2019). During P. falciparum blood-stage infections in humans, low-density lipoprotein, high-density lipoprotein and cholesterol levels in the blood become low. Because P. falciparum lacks a de novo cholesterol synthesis pathway, it must import cholesterol from the surrounding environment. However, the origin of the cholesterol and how it is taken up by the parasite across the multiple membranes that surround it is not fully understood. To answer this, we used a cholesterol synthesis inhibiter (simvastatin), a cholesterol transport inhibitor (ezetimibe), and an activating ligand of the peroxisome proliferator-activated receptor α, called ciprofibrate, to investigate the effects of these agents on the intraerythrocytic growth of P. falciparum, both with and without HepG2 cells as the lipoprotein feeders. P. falciparum growth was inhibited in the presence of ezetimibe, but ezetimibe was not very effective at inhibiting P. falciparum growth when used in the co-culture system, unlike simvastatin, which strongly promoted parasite growth in this system. Ezetimibe is known to inhibit cholesterol absorption by blocking the activity of Niemann-Pick C1 like 1 (NPC1L1) protein, and simvastatin is known to enhance NPC1L1 expression in the human body's small intestine. Collectively, our results support the possibility that cholesterol import by P. falciparum involves hepatocytes, and cholesterol uptake into the parasite occurs via NPC1L1 protein or an NPC1L1 homolog during the erythrocytic stages of the P. falciparum lifecycle.
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Affiliation(s)
- Eri H Hayakawa
- Division of Medical Zoology, Department of Infection and Immunity, Jichi Medical University, Shimotsuke, Tochigi 329-0498, Japan.
| | - Hirotomo Kato
- Division of Medical Zoology, Department of Infection and Immunity, Jichi Medical University, Shimotsuke, Tochigi 329-0498, Japan
| | - Glenn A Nardone
- Research Technology Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-5766, USA
| | - Jiro Usukura
- Institute of Material and Systems for Sustainability, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
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Stanway RR, Bushell E, Chiappino-Pepe A, Roques M, Sanderson T, Franke-Fayard B, Caldelari R, Golomingi M, Nyonda M, Pandey V, Schwach F, Chevalley S, Ramesar J, Metcalf T, Herd C, Burda PC, Rayner JC, Soldati-Favre D, Janse CJ, Hatzimanikatis V, Billker O, Heussler VT. Genome-Scale Identification of Essential Metabolic Processes for Targeting the Plasmodium Liver Stage. Cell 2020; 179:1112-1128.e26. [PMID: 31730853 PMCID: PMC6904910 DOI: 10.1016/j.cell.2019.10.030] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 07/23/2019] [Accepted: 10/23/2019] [Indexed: 12/11/2022]
Abstract
Plasmodium gene functions in mosquito and liver stages remain poorly characterized due to limitations in the throughput of phenotyping at these stages. To fill this gap, we followed more than 1,300 barcoded P. berghei mutants through the life cycle. We discover 461 genes required for efficient parasite transmission to mosquitoes through the liver stage and back into the bloodstream of mice. We analyze the screen in the context of genomic, transcriptomic, and metabolomic data by building a thermodynamic model of P. berghei liver-stage metabolism, which shows a major reprogramming of parasite metabolism to achieve rapid growth in the liver. We identify seven metabolic subsystems that become essential at the liver stages compared with asexual blood stages: type II fatty acid synthesis and elongation (FAE), tricarboxylic acid, amino sugar, heme, lipoate, and shikimate metabolism. Selected predictions from the model are individually validated in single mutants to provide future targets for drug development. 1,342 barcoded P. berghei knockout (KO) mutants analyzed for stage-specific phenotypes Life-stage-specific metabolic models reveal reprogramming of cellular function High agreement between blood/liver stage metabolic models and genetic screening data Essential metabolic pathways for parasite development and mechanistic origin revealed
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Affiliation(s)
- Rebecca R Stanway
- Institute of Cell Biology, University of Bern, Bern 3012, Switzerland
| | - Ellen Bushell
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SA, UK; Molecular Infection Medicine Sweden (MIMS), Department of Molecular Biology, Umeå University, Umeå 901 87, Sweden
| | - Anush Chiappino-Pepe
- Laboratory of Computational Systems Biotechnology, École Polytechnique Fédérale de Lausanne, EPFL, Lausanne 1015, Switzerland
| | - Magali Roques
- Institute of Cell Biology, University of Bern, Bern 3012, Switzerland
| | - Theo Sanderson
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Blandine Franke-Fayard
- Leiden Malaria Research Group, Parasitology, Center of Infectious Diseases, Leiden University Medical Center (LUMC), Leiden 2333ZA, the Netherlands
| | - Reto Caldelari
- Institute of Cell Biology, University of Bern, Bern 3012, Switzerland
| | | | - Mary Nyonda
- Department of Microbiology & Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva 1211, Switzerland
| | - Vikash Pandey
- Laboratory of Computational Systems Biotechnology, École Polytechnique Fédérale de Lausanne, EPFL, Lausanne 1015, Switzerland; Molecular Infection Medicine Sweden (MIMS), Department of Molecular Biology, Umeå University, Umeå 901 87, Sweden
| | - Frank Schwach
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Séverine Chevalley
- Leiden Malaria Research Group, Parasitology, Center of Infectious Diseases, Leiden University Medical Center (LUMC), Leiden 2333ZA, the Netherlands
| | - Jai Ramesar
- Leiden Malaria Research Group, Parasitology, Center of Infectious Diseases, Leiden University Medical Center (LUMC), Leiden 2333ZA, the Netherlands
| | - Tom Metcalf
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Colin Herd
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Paul-Christian Burda
- Institute of Cell Biology, University of Bern, Bern 3012, Switzerland; Bernhard Nocht Institute for Tropical Medicine, Hamburg 20359, Germany
| | - Julian C Rayner
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SA, UK; Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2, 0XY, UK
| | - Dominique Soldati-Favre
- Department of Microbiology & Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva 1211, Switzerland
| | - Chris J Janse
- Leiden Malaria Research Group, Parasitology, Center of Infectious Diseases, Leiden University Medical Center (LUMC), Leiden 2333ZA, the Netherlands
| | - Vassily Hatzimanikatis
- Laboratory of Computational Systems Biotechnology, École Polytechnique Fédérale de Lausanne, EPFL, Lausanne 1015, Switzerland
| | - Oliver Billker
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SA, UK; Molecular Infection Medicine Sweden (MIMS), Department of Molecular Biology, Umeå University, Umeå 901 87, Sweden.
| | - Volker T Heussler
- Institute of Cell Biology, University of Bern, Bern 3012, Switzerland.
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Gupta A, Bokhari AAB, Pillai AD, Crater AK, Gezelle J, Saggu G, Nasamu AS, Ganesan SM, Niles JC, Desai SA. Complex nutrient channel phenotypes despite Mendelian inheritance in a Plasmodium falciparum genetic cross. PLoS Pathog 2020; 16:e1008363. [PMID: 32069335 PMCID: PMC7048409 DOI: 10.1371/journal.ppat.1008363] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 02/28/2020] [Accepted: 01/28/2020] [Indexed: 12/30/2022] Open
Abstract
Malaria parasites activate a broad-selectivity ion channel on their host erythrocyte membrane to obtain essential nutrients from the bloodstream. This conserved channel, known as the plasmodial surface anion channel (PSAC), has been linked to parasite clag3 genes in P. falciparum, but epigenetic switching between the two copies of this gene hinders clear understanding of how the encoded protein determines PSAC activity. Here, we used linkage analysis in a P. falciparum cross where one parent carries a single clag3 gene to overcome the effects of switching and confirm a primary role of the clag3 product with high confidence. Despite Mendelian inheritance, CLAG3 conditional knockdown revealed remarkably preserved nutrient and solute uptake. Even more surprisingly, transport remained sensitive to a CLAG3 isoform-specific inhibitor despite quantitative knockdown, indicating that low doses of the CLAG3 transgene are sufficient to confer block. We then produced a complete CLAG3 knockout line and found it exhibits an incomplete loss of transport activity, in contrast to rhoph2 and rhoph3, two PSAC-associated genes that cannot be disrupted because nutrient uptake is abolished in their absence. Although the CLAG3 knockout did not incur a fitness cost under standard nutrient-rich culture conditions, this parasite could not be propagated in a modified medium that more closely resembles human plasma. These studies implicate oligomerization of CLAG paralogs encoded by various chromosomes in channel formation. They also reveal that CLAG3 is dispensable under standard in vitro conditions but required for propagation under physiological conditions.
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Affiliation(s)
- Ankit Gupta
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Abdullah A. B. Bokhari
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Ajay D. Pillai
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Anna K. Crater
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Jeanine Gezelle
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Gagandeep Saggu
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Armiyaw S. Nasamu
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Suresh M. Ganesan
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Jacquin C. Niles
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Sanjay A. Desai
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
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Duffy S, Avery VM. Routine In Vitro Culture of Plasmodium falciparum: Experimental Consequences? Trends Parasitol 2018; 34:564-575. [DOI: 10.1016/j.pt.2018.04.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 04/20/2018] [Accepted: 04/23/2018] [Indexed: 12/20/2022]
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9
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Lim YB, Nai MH, Cao J, Loh KP, Lim CT. Graphene oxide inhibits malaria parasite invasion and delays parasitic growth in vitro. NANOSCALE 2017; 9:14065-14073. [PMID: 28901366 DOI: 10.1039/c7nr06007f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The interactions between graphene oxide (GO) and various biological entities have been actively investigated in recent years, resulting in numerous potential bioapplications of these nanomaterials. Despite this, the biological interactions between GO and disease-causing protozoan parasites have not been well elucidated and remain relatively unexplored. Here, we investigate the in vitro interactions between GO nanosheets and a particular species of malaria parasites, Plasmodium falciparum (P. falciparum). We hypothesize that GO nanosheets may exhibit antimalarial characteristic via action mechanisms of physical obstruction of P. falciparum parasites as well as nutrient depletion. To ascertain this, we characterize the physical interactions between GO nanosheets, red blood cells (RBCs), and malarial parasites as well as the adsorption of several biomolecules necessary for parasitic survival and growth on GO nanosheets. Subsequent to establishing the origin of this antimalarial behavior of GO nanosheets, their efficiency in inhibiting parasite invasion is evaluated. We observe that GO nanosheets at various tested concentrations significantly inhibit the invasion of malaria parasites into RBCs. Furthermore, GO nanosheets delay parasite progression from the ring to the trophozoite stage. Overall, this study may further shed light on the graphene-parasite interactions and potentially facilitate the development of nanomaterial-based strategies for combating malaria.
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Affiliation(s)
- Ying Bena Lim
- Department of Biomedical Engineering, National University of Singapore, Singapore 117576. and Singapore-MIT Alliance for Research and Technology (SMART) Centre, Infectious Diseases IRG, Singapore 138602
| | - Mui Hoon Nai
- Mechanobiology Institute, National University of Singapore, Singapore 117411
| | - Jianshu Cao
- Singapore-MIT Alliance for Research and Technology (SMART) Centre, Infectious Diseases IRG, Singapore 138602 and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, USA 02139
| | - Kian Ping Loh
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117456 and Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore 117543 and Department of Chemistry, National University of Singapore, Singapore 117543
| | - Chwee Teck Lim
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117456 and Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore 117543 and Department of Biomedical Engineering, National University of Singapore, Singapore 117576. and Singapore-MIT Alliance for Research and Technology (SMART) Centre, Infectious Diseases IRG, Singapore 138602 and Mechanobiology Institute, National University of Singapore, Singapore 117411
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10
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Charnaud SC, Dixon MWA, Nie CQ, Chappell L, Sanders PR, Nebl T, Hanssen E, Berriman M, Chan JA, Blanch AJ, Beeson JG, Rayner JC, Przyborski JM, Tilley L, Crabb BS, Gilson PR. The exported chaperone Hsp70-x supports virulence functions for Plasmodium falciparum blood stage parasites. PLoS One 2017; 12:e0181656. [PMID: 28732045 PMCID: PMC5521827 DOI: 10.1371/journal.pone.0181656] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 07/05/2017] [Indexed: 12/03/2022] Open
Abstract
Malaria is caused by five different Plasmodium spp. in humans each of which modifies the host erythrocyte to survive and replicate. The two main causes of malaria, P. falciparum and P. vivax, differ in their ability to cause severe disease, mainly due to differences in the cytoadhesion of infected erythrocytes (IE) in the microvasculature. Cytoadhesion of P. falciparum in the brain leads to a large number of deaths each year and is a consequence of exported parasite proteins, some of which modify the erythrocyte cytoskeleton while others such as PfEMP1 project onto the erythrocyte surface where they bind to endothelial cells. Here we investigate the effects of knocking out an exported Hsp70-type chaperone termed Hsp70-x that is present in P. falciparum but not P. vivax. Although the growth of Δhsp70-x parasites was unaffected, the export of PfEMP1 cytoadherence proteins was delayed and Δhsp70-x IE had reduced adhesion. The Δhsp70-x IE were also more rigid than wild-type controls indicating changes in the way the parasites modified their host erythrocyte. To investigate the cause of this, transcriptional and translational changes in exported and chaperone proteins were monitored and some changes were observed. We propose that PfHsp70-x is not essential for survival in vitro, but may be required for the efficient export and functioning of some P. falciparum exported proteins.
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Affiliation(s)
| | - Matthew W. A. Dixon
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Melbourne, Victoria, Australia
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria, Australia
| | | | - Lia Chappell
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, United Kingdom
| | | | - Thomas Nebl
- Walter & Eliza Hall Institute, Melbourne, Victoria, Australia
| | - Eric Hanssen
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria, Australia
| | - Matthew Berriman
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, United Kingdom
| | - Jo-Anne Chan
- Burnet Institute, Melbourne, Victoria, Australia
| | - Adam J. Blanch
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Melbourne, Victoria, Australia
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria, Australia
| | | | - Julian C. Rayner
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, United Kingdom
| | | | - Leann Tilley
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Melbourne, Victoria, Australia
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria, Australia
| | - Brendan S. Crabb
- Burnet Institute, Melbourne, Victoria, Australia
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Melbourne, Victoria, Australia
- Monash University, Melbourne, Victoria, Australia
| | - Paul R. Gilson
- Burnet Institute, Melbourne, Victoria, Australia
- Monash University, Melbourne, Victoria, Australia
- * E-mail:
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11
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Chiappino-Pepe A, Tymoshenko S, Ataman M, Soldati-Favre D, Hatzimanikatis V. Bioenergetics-based modeling of Plasmodium falciparum metabolism reveals its essential genes, nutritional requirements, and thermodynamic bottlenecks. PLoS Comput Biol 2017; 13:e1005397. [PMID: 28333921 PMCID: PMC5363809 DOI: 10.1371/journal.pcbi.1005397] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 02/04/2017] [Indexed: 11/30/2022] Open
Abstract
Novel antimalarial therapies are urgently needed for the fight against drug-resistant parasites. The metabolism of malaria parasites in infected cells is an attractive source of drug targets but is rather complex. Computational methods can handle this complexity and allow integrative analyses of cell metabolism. In this study, we present a genome-scale metabolic model (iPfa) of the deadliest malaria parasite, Plasmodium falciparum, and its thermodynamics-based flux analysis (TFA). Using previous absolute concentration data of the intraerythrocytic parasite, we applied TFA to iPfa and predicted up to 63 essential genes and 26 essential pairs of genes. Of the 63 genes, 35 have been experimentally validated and reported in the literature, and 28 have not been experimentally tested and include previously hypothesized or novel predictions of essential metabolic capabilities. Without metabolomics data, four of the genes would have been incorrectly predicted to be non-essential. TFA also indicated that substrate channeling should exist in two metabolic pathways to ensure the thermodynamic feasibility of the flux. Finally, analysis of the metabolic capabilities of P. falciparum led to the identification of both the minimal nutritional requirements and the genes that can become indispensable upon substrate inaccessibility. This model provides novel insight into the metabolic needs and capabilities of the malaria parasite and highlights metabolites and pathways that should be measured and characterized to identify potential thermodynamic bottlenecks and substrate channeling. The hypotheses presented seek to guide experimental studies to facilitate a better understanding of the parasite metabolism and the identification of targets for more efficient intervention. Almost half of the world population is at risk of infection by malaria parasites. The rise in drug-resistant parasites requires better understanding and targeting of their metabolism. In this study, we present a genome-scale metabolic reconstruction (iPfa) of the deadliest malaria parasite, Plasmodium falciparum, and its thermodynamics-based flux analysis (TFA). Our results support and extend the available experimental evidence on the essential genes and nutritional requirements of this organism. Besides, we identify metabolites that give rise to thermodynamic bottlenecks and suggest substrate channeling. Overall, these results provide novel insight into the metabolism of P. falciparum and may guide experimental studies to develop a better characterization of the parasite metabolism and the identification of antimalarial drug targets.
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Affiliation(s)
- Anush Chiappino-Pepe
- Laboratory of Computational Systems Biotechnology, École Polytechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland
| | - Stepan Tymoshenko
- Laboratory of Computational Systems Biotechnology, École Polytechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, CMU, Geneva, Switzerland
| | - Meriç Ataman
- Laboratory of Computational Systems Biotechnology, École Polytechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, CMU, Geneva, Switzerland
| | - Vassily Hatzimanikatis
- Laboratory of Computational Systems Biotechnology, École Polytechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland
- * E-mail:
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12
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Pandey K, Ferreira PE, Ishikawa T, Nagai T, Kaneko O, Yahata K. Ca(2+) monitoring in Plasmodium falciparum using the yellow cameleon-Nano biosensor. Sci Rep 2016; 6:23454. [PMID: 27006284 PMCID: PMC4804237 DOI: 10.1038/srep23454] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 03/07/2016] [Indexed: 11/09/2022] Open
Abstract
Calcium (Ca(2+))-mediated signaling is a conserved mechanism in eukaryotes, including the human malaria parasite, Plasmodium falciparum. Due to its small size (<10 μm) measurement of intracellular Ca(2+) in Plasmodium is technically challenging, and thus Ca(2+) regulation in this human pathogen is not well understood. Here we analyze Ca(2+) homeostasis via a new approach using transgenic P. falciparum expressing the Ca(2+) sensor yellow cameleon (YC)-Nano. We found that cytosolic Ca(2+) concentration is maintained at low levels only during the intraerythrocytic trophozoite stage (30 nM), and is increased in the other blood stages (>300 nM). We determined that the mammalian SERCA inhibitor thapsigargin and antimalarial dihydroartemisinin did not perturb SERCA activity. The change of the cytosolic Ca(2+) level in P. falciparum was additionally detectable by flow cytometry. Thus, we propose that the developed YC-Nano-based system is useful to study Ca(2+) signaling in P. falciparum and is applicable for drug screening.
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Affiliation(s)
- Kishor Pandey
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
- Nepal Academy of Science and Technology (NAST), GPO Box: 3323, Khumaltar, Lalitpur, Nepal
| | - Pedro E. Ferreira
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
- School of Biological Science, Nanyang Technological University, Singapore
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal
| | - Takeshi Ishikawa
- Department of Molecular Microbiology and Immunology, Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
| | - Takeharu Nagai
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Osamu Kaneko
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
| | - Kazuhide Yahata
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
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13
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Why do malaria parasites increase host erythrocyte permeability? Trends Parasitol 2014; 30:151-9. [PMID: 24507014 DOI: 10.1016/j.pt.2014.01.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 01/06/2014] [Accepted: 01/09/2014] [Indexed: 11/21/2022]
Abstract
Malaria parasites increase erythrocyte permeability to diverse solutes including anions, some cations, and organic solutes, as characterized with several independent methods. Over the past decade, patch-clamp studies have determined that the permeability results from one or more ion channels on the infected erythrocyte host membrane. However, the biological role(s) served by these channels, if any, remain controversial. Recent studies implicate the plasmodial surface anion channel (PSAC) and a role in parasite nutrient acquisition. A debated alternative role in remodeling host ion composition for the benefit of the parasite appears to be nonessential. Because both channel activity and the associated clag3 genes are strictly conserved in malaria parasites, channel-mediated permeability is an attractive target for development of new therapies.
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