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Arbon D, Mach J, Čadková A, Sipkova A, Stursa J, Klanicová K, Machado M, Ganter M, Levytska V, Sojka D, Truksa J, Werner L, Sutak R. Chelation of Mitochondrial Iron as an Antiparasitic Strategy. ACS Infect Dis 2024; 10:676-687. [PMID: 38287902 PMCID: PMC10862539 DOI: 10.1021/acsinfecdis.3c00529] [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: 10/02/2023] [Revised: 01/02/2024] [Accepted: 01/09/2024] [Indexed: 01/31/2024]
Abstract
Iron, as an essential micronutrient, plays a crucial role in host-pathogen interactions. In order to limit the growth of the pathogen, a common strategy of innate immunity includes withdrawing available iron to interfere with the cellular processes of the microorganism. Against that, unicellular parasites have developed powerful strategies to scavenge iron, despite the effort of the host. Iron-sequestering compounds, such as the approved and potent chelator deferoxamine (DFO), are considered a viable option for therapeutic intervention. Since iron is heavily utilized in the mitochondrion, targeting iron chelators in this organelle could constitute an effective therapeutic strategy. This work presents mitochondrially targeted DFO, mitoDFO, as a candidate against a range of unicellular parasites with promising in vitro efficiency. Intracellular Leishmania infection can be cleared by this compound, and experimentation with Trypanosoma brucei 427 elucidates its possible mode of action. The compound not only affects iron homeostasis but also alters the physiochemical properties of the inner mitochondrial membrane, resulting in a loss of function. Furthermore, investigating the virulence factors of pathogenic yeasts confirms that mitoDFO is a viable candidate for therapeutic intervention against a wide spectrum of microbe-associated diseases.
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Affiliation(s)
- Dominik Arbon
- Department of Parasitology, Faculty
of Science, Charles University, BIOCEV, Vestec 25250, Czech Republic
| | - Jan Mach
- Department of Parasitology, Faculty
of Science, Charles University, BIOCEV, Vestec 25250, Czech Republic
| | - Aneta Čadková
- Department of Parasitology, Faculty
of Science, Charles University, BIOCEV, Vestec 25250, Czech Republic
| | - Anna Sipkova
- Department of Parasitology, Faculty
of Science, Charles University, BIOCEV, Vestec 25250, Czech Republic
| | - Jan Stursa
- Institute
of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec 25250, Czech Republic
- Laboratory
of Clinical Pathophysiology, Diabetes Centre, Institute for Clinical and Experimental Medicine, Videnska 1958/9, 140 21 Prague, Czech
Republic
| | - Kristýna Klanicová
- Institute
of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec 25250, Czech Republic
- Department
of Organic Chemistry, Faculty of Science, Charles University, Prague 128 00, Czech Republic
| | - Marta Machado
- Graduate
Program in Areas of Basic and Applied Biology, Instituto de Ciências
Biomédicas Abel Salazar, Universidade
do Porto, Porto 4050-313, Portugal
- Centre for
Infectious Diseases, Parasitology, Heidelberg
University Hospital, Heidelberg 69120, Germany
| | - Markus Ganter
- Centre for
Infectious Diseases, Parasitology, Heidelberg
University Hospital, Heidelberg 69120, Germany
| | - Viktoriya Levytska
- Institute
of Parasitology, Biology Centre, Academy
of Sciences of the Czech Republic, Branišovská 1160/31, České Budějovice 37005, Czech Republic
| | - Daniel Sojka
- Institute
of Parasitology, Biology Centre, Academy
of Sciences of the Czech Republic, Branišovská 1160/31, České Budějovice 37005, Czech Republic
| | - Jaroslav Truksa
- Institute
of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec 25250, Czech Republic
| | - Lukáš Werner
- Institute
of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec 25250, Czech Republic
- Laboratory
of Clinical Pathophysiology, Diabetes Centre, Institute for Clinical and Experimental Medicine, Videnska 1958/9, 140 21 Prague, Czech
Republic
| | - Robert Sutak
- Department of Parasitology, Faculty
of Science, Charles University, BIOCEV, Vestec 25250, Czech Republic
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The 4-Aminomethylphenoxy-Benzoxaborole AN3057 as a Potential Treatment Option for Primary Amoebic Meningoencephalitis. Antimicrob Agents Chemother 2023; 67:e0150622. [PMID: 36688657 PMCID: PMC9933681 DOI: 10.1128/aac.01506-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Primary amoebic meningoencephalitis is a rare but fatal central nervous system (CNS) disease caused by the "brain-eating amoeba" Naegleria fowleri. A major obstacle is the requirement for drugs with the ability to cross the blood-brain barrier, which are used in extremely high doses, cause severe side effects, and are usually ineffective. We discovered that the 4-aminomethylphenoxy-benzoxaborole AN3057 exhibits nanomolar potency against N. fowleri, and experimental treatment of infected mice significantly prolonged survival and demonstrated a 28% relapse-free cure rate.
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Dereeper A, Allouch N, Guerlais V, Garnier M, Ma L, De Jonckheere JF, Joseph SJ, Ali IKM, Talarmin A, Marcelino I. Naegleria genus pangenome reveals new structural and functional insights into the versatility of these free-living amoebae. Front Microbiol 2023; 13:1056418. [PMID: 36817109 PMCID: PMC9928731 DOI: 10.3389/fmicb.2022.1056418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 12/21/2022] [Indexed: 02/04/2023] Open
Abstract
Introduction Free-living amoebae of the Naegleria genus belong to the major protist clade Heterolobosea and are ubiquitously distributed in soil and freshwater habitats. Of the 47 Naegleria species described, N. fowleri is the only one being pathogenic to humans, causing a rare but fulminant primary amoebic meningoencephalitis. Some Naegleria genome sequences are publicly available, but the genetic basis for Naegleria diversity and ability to thrive in diverse environments (including human brain) remains unclear. Methods Herein, we constructed a high-quality Naegleria genus pangenome to obtain a comprehensive catalog of genes encoded by these amoebae. For this, we first sequenced, assembled, and annotated six new Naegleria genomes. Results and Discussion Genome architecture analyses revealed that Naegleria may use genome plasticity features such as ploidy/aneuploidy to modulate their behavior in different environments. When comparing 14 near-to-complete genome sequences, our results estimated the theoretical Naegleria pangenome as a closed genome, with 13,943 genes, including 3,563 core and 10,380 accessory genes. The functional annotations revealed that a large fraction of Naegleria genes show significant sequence similarity with those already described in other kingdoms, namely Animalia and Plantae. Comparative analyses highlighted a remarkable genomic heterogeneity, even for closely related strains and demonstrate that Naegleria harbors extensive genome variability, reflected in different metabolic repertoires. If Naegleria core genome was enriched in conserved genes essential for metabolic, regulatory and survival processes, the accessory genome revealed the presence of genes involved in stress response, macromolecule modifications, cell signaling and immune response. Commonly reported N. fowleri virulence-associated genes were present in both core and accessory genomes, suggesting that N. fowleri's ability to infect human brain could be related to its unique species-specific genes (mostly of unknown function) and/or to differential gene expression. The construction of Naegleria first pangenome allowed us to move away from a single reference genome (that does not necessarily represent each species as a whole) and to identify essential and dispensable genes in Naegleria evolution, diversity and biology, paving the way for further genomic and post-genomic studies.
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Affiliation(s)
- Alexis Dereeper
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Nina Allouch
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Vincent Guerlais
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Maëlle Garnier
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Laurence Ma
- Institut Pasteur de Paris, Biomics, Paris, France
| | | | - Sandeep J. Joseph
- Centers for Disease Control and Prevention (CDC), Atlanta, GA, United States
| | - Ibne Karim M. Ali
- Centers for Disease Control and Prevention (CDC), Atlanta, GA, United States
| | - Antoine Talarmin
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Isabel Marcelino
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France,*Correspondence: Isabel Marcelino,
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Celis AI, Relman DA, Huang KC. The impact of iron and heme availability on the healthy human gut microbiome in vivo and in vitro. Cell Chem Biol 2023; 30:110-126.e3. [PMID: 36603582 PMCID: PMC9913275 DOI: 10.1016/j.chembiol.2022.12.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 07/12/2022] [Accepted: 12/14/2022] [Indexed: 01/06/2023]
Abstract
Responses of the indigenous human gut commensal microbiota to iron are poorly understood because of an emphasis on in vitro studies of pathogen iron sensitivity. In a study of iron supplementation in healthy humans, we identified gradual microbiota shifts in some participants correlated with bacterial iron internalization. To identify direct effects due to taxon-specific iron sensitivity, we used participant stool samples to derive diverse in vitro communities. Iron supplementation of these communities caused small compositional shifts, mimicking those in vivo, whereas iron deprivation dramatically inhibited growth with irreversible, cumulative reduction in diversity and replacement of dominant species. Sensitivity of individual species to iron deprivation in axenic culture generally predicted iron dependency in a community. Finally, exogenous heme acted as a source of inorganic iron to prevent depletion of some species. Our results highlight the complementarity of in vivo and in vitro studies in understanding how environmental factors affect gut microbiotas.
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Affiliation(s)
- Arianna I Celis
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - David A Relman
- Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA; Infectious Diseases Section, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
| | - Kerwyn Casey Huang
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
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5
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Repurposing of MitoTam: Novel Anti-Cancer Drug Candidate Exhibits Potent Activity against Major Protozoan and Fungal Pathogens. Antimicrob Agents Chemother 2022; 66:e0072722. [PMID: 35856666 PMCID: PMC9380531 DOI: 10.1128/aac.00727-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Many of the currently available anti-parasitic and anti-fungal frontline drugs have severe limitations, including adverse side effects, complex administration, and increasing occurrence of resistance. The discovery and development of new therapeutic agents is a costly and lengthy process. Therefore, repurposing drugs with already established clinical application offers an attractive, fast-track approach for novel treatment options. In this study, we show that the anti-cancer drug candidate MitoTam, a mitochondria-targeted analog of tamoxifen, efficiently eliminates a wide range of evolutionarily distinct pathogens in vitro, including pathogenic fungi, Plasmodium falciparum, and several species of trypanosomatid parasites, causative agents of debilitating neglected tropical diseases. MitoTam treatment was also effective in vivo and significantly reduced parasitemia of two medically important parasites, Leishmania mexicana and Trypanosoma brucei, in their respective animal infection models. Functional analysis in the bloodstream form of T. brucei showed that MitoTam rapidly altered mitochondrial functions, particularly affecting cellular respiration, lowering ATP levels, and dissipating mitochondrial membrane potential. Our data suggest that the mode of action of MitoTam involves disruption of the inner mitochondrial membrane, leading to rapid organelle depolarization and cell death. Altogether, MitoTam is an excellent candidate drug against several important pathogens, for which there are no efficient therapies and for which drug development is not a priority.
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6
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Grechnikova M, Arbon D, Ženíšková K, Malych R, Mach J, Krejbichová L, Šimáčková A, Sutak R. Elucidation of iron homeostasis in Acanthamoeba castellanii. Int J Parasitol 2022; 52:497-508. [PMID: 35533729 DOI: 10.1016/j.ijpara.2022.03.007] [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: 12/03/2021] [Revised: 03/21/2022] [Accepted: 03/27/2022] [Indexed: 11/25/2022]
Abstract
Acanthamoeba castellanii is a ubiquitously distributed amoeba that can be found in soil, dust, natural and tap water, air conditioners, hospitals, contact lenses and other environments. It is an amphizoic organism that can cause granulomatous amoebic encephalitis, an infrequent fatal disease of the central nervous system, and amoebic keratitis, a severe corneal infection that can lead to blindness. These diseases are extremely hard to treat; therefore, a more comprehensive understanding of this pathogen's metabolism is essential for revealing potential therapeutic targets. To propagate successfully in human tissues, the parasites must resist the iron depletion caused by nutritional immunity. The aim of our study is to elucidate the mechanisms underlying iron homeostasis in A. castellanii. Using a comparative whole-cell proteomic analysis of cells grown under different degrees of iron availability, we identified the primary proteins involved in Acanthamoeba iron acquisition. Our results suggest a two-step reductive mechanism of iron acquisition by a ferric reductase from the STEAP family and a divalent metal transporter from the NRAMP family. Both proteins are localized to the membranes of acidified digestive vacuoles where endocytosed medium and bacteria are trafficked. The expression levels of these proteins are significantly higher under iron-limited conditions, which allows Acanthamoeba to increase the efficiency of iron uptake despite the observed reduced pinocytosis rate. We propose that excessive iron gained while grown under iron-rich conditions is removed from the cytosol into the vacuoles by an iron transporter homologous to VIT/Ccc1 proteins. Additionally, we identified a novel protein that may participate in iron uptake regulation, the overexpression of which leads to increased iron acquisition.
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Affiliation(s)
- Maria Grechnikova
- Department of Parasitology, Charles University, Faculty of Science, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Dominik Arbon
- Department of Parasitology, Charles University, Faculty of Science, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Kateřina Ženíšková
- Department of Parasitology, Charles University, Faculty of Science, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Ronald Malych
- Department of Parasitology, Charles University, Faculty of Science, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Jan Mach
- Department of Parasitology, Charles University, Faculty of Science, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Lucie Krejbichová
- Department of Parasitology, Charles University, Faculty of Science, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Aneta Šimáčková
- Department of Parasitology, Charles University, Faculty of Science, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Robert Sutak
- Department of Parasitology, Charles University, Faculty of Science, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic.
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Ženíšková K, Grechnikova M, Sutak R. Copper Metabolism in Naegleria gruberi and Its Deadly Relative Naegleria fowleri. Front Cell Dev Biol 2022; 10:853463. [PMID: 35478954 PMCID: PMC9035749 DOI: 10.3389/fcell.2022.853463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 03/18/2022] [Indexed: 12/04/2022] Open
Abstract
Although copper is an essential nutrient crucial for many biological processes, an excessive concentration can be toxic and lead to cell death. The metabolism of this two-faced metal must be strictly regulated at the cell level. In this study, we investigated copper homeostasis in two related unicellular organisms: nonpathogenic Naegleria gruberi and the “brain-eating amoeba” Naegleria fowleri. We identified and confirmed the function of their specific copper transporters securing the main pathway of copper acquisition. Adjusting to different environments with varying copper levels during the life cycle of these organisms requires various metabolic adaptations. Using comparative proteomic analyses, measuring oxygen consumption, and enzymatic determination of NADH dehydrogenase, we showed that both amoebas respond to copper deprivation by upregulating the components of the branched electron transport chain: the alternative oxidase and alternative NADH dehydrogenase. Interestingly, analysis of iron acquisition indicated that this system is copper-dependent in N. gruberi but not in its pathogenic relative. Importantly, we identified a potential key protein of copper metabolism of N. gruberi, the homolog of human DJ-1 protein, which is known to be linked to Parkinson’s disease. Altogether, our study reveals the mechanisms underlying copper metabolism in the model amoeba N. gruberi and the fatal pathogen N. fowleri and highlights the differences between the two amoebas.
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8
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Malych R, Füssy Z, Ženíšková K, Arbon D, Hampl V, Hrdý I, Sutak R. The response of Naegleria gruberi to oxidative stress. Metallomics 2022; 14:6527579. [PMID: 35150262 DOI: 10.1093/mtomcs/mfac009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 02/06/2022] [Indexed: 11/14/2022]
Abstract
Aerobic organisms require oxygen for respiration but must simultaneously cope with oxidative damages inherently linked with this molecule. Unicellular amoeboflagellates of the genus Naegleria, containing both free-living species and opportunistic parasite, thrive in aerobic environments. However, they are also known to maintain typical features of anaerobic organisms. Here, we describe the mechanisms of oxidative damage mitigation in Naegleria gruberi and focus on the molecular characteristics of three noncanonical proteins interacting with oxygen and its derived reactive forms. We show that this protist expresses hemerythrin, protoglobin and an aerobic-type rubrerythrin, with spectral properties characteristic of the cofactors they bind. We provide evidence that protoglobin and hemerythrin interact with oxygen in vitro and confirm the mitochondrial localization of rubrerythrin by immunolabeling. Our proteomic analysis and immunoblotting following heavy metal treatment revealed upregulation of hemerythrin, while rotenone treatment resulted in an increase in rubrerythrin protein levels together with vast upregulation of alternative oxidase. Our study provided new insights into the mechanisms employed by N. gruberi to cope with different types of oxidative stress and allowed us to propose specific roles for three unique and understudied proteins: hemerythrin, protoglobin and rubrerythrin.
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Affiliation(s)
- Ronald Malych
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Zoltán Füssy
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Kateřina Ženíšková
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Dominik Arbon
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Vladimír Hampl
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Ivan Hrdý
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Robert Sutak
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
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9
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Differential Growth Rates and In Vitro Drug Susceptibility to Currently Used Drugs for Multiple Isolates of Naegleria fowleri. Microbiol Spectr 2022; 10:e0189921. [PMID: 35138140 PMCID: PMC8826828 DOI: 10.1128/spectrum.01899-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The free-living amoeba Naegleria fowleri, which typically dwells within warm, freshwater environments, can opportunistically cause primary amoebic meningoencephalitis (PAM), a disease with a mortality rate of >97%. The lack of positive treatment outcomes for PAM has prompted the discovery and development of more effective therapeutics, yet most studies utilize only one or two clinical isolates. The inability to assess possible heterogenic responses to drugs among isolates from various geographical regions hinders progress in the discovery of more effective drugs. Here, we conducted drug efficacy and growth rate determinations for 11 different clinical isolates by applying a previously developed CellTiter-Glo 2.0 screening technique and flow cytometry. We found significant differences in the susceptibilities of these isolates to 7 of 8 drugs tested, all of which make up the cocktail that is recommended to physicians by the U.S. Centers for Disease Control and Prevention. We also discovered significant variances in growth rates among isolates, which draws attention to the differences among the amoeba isolates collected from different patients. Our results demonstrate the need for additional clinical isolates of various genotypes in drug assays and highlight the necessity for more targeted therapeutics with universal efficacy across N. fowleri isolates. Our data establish a needed baseline for drug susceptibility among clinical isolates and provide a segue for future combination therapy studies as well as research related to phenotypic or genetic differences that could shed light on mechanisms of action or predispositions to specific drugs. IMPORTANCENaegleria fowleri, also known as the brain-eating amoeba, is ubiquitous in warm freshwater and is an opportunistic pathogen that causes primary amoebic meningoencephalitis. Although few cases are described each year, the disease has a case fatality rate of >97%. In most laboratory studies of this organism, only one or two well-adapted lab strains are used; therefore, there is a lack of data to discern if there are major differences in potency of currently used drugs for multiple strains and genotypes of the amoeba. In this study, we found significant differences in the susceptibilities of 11 N. fowleri isolates to 7 of the 8 drugs currently used to treat the disease. The data from this study provide a baseline of drug susceptibility among clinical isolates and suggest that new drugs should be tested on a larger number of isolates in the future.
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10
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Gilabert Carbajo C, Cornell LJ, Madbouly Y, Lai Z, Yates PA, Tinti M, Tiengwe C. Novel aspects of iron homeostasis in pathogenic bloodstream form Trypanosoma brucei. PLoS Pathog 2021; 17:e1009696. [PMID: 34161395 PMCID: PMC8259959 DOI: 10.1371/journal.ppat.1009696] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 07/06/2021] [Accepted: 06/04/2021] [Indexed: 01/09/2023] Open
Abstract
Iron is an essential regulatory signal for virulence factors in many pathogens. Mammals and bloodstream form (BSF) Trypanosoma brucei obtain iron by receptor-mediated endocytosis of transferrin bound to receptors (TfR) but the mechanisms by which T. brucei subsequently handles iron remains enigmatic. Here, we analyse the transcriptome of T. brucei cultured in iron-rich and iron-poor conditions. We show that adaptation to iron-deprivation induces upregulation of TfR, a cohort of parasite-specific genes (ESAG3, PAGS), genes involved in glucose uptake and glycolysis (THT1 and hexokinase), endocytosis (Phosphatidic Acid Phosphatase, PAP2), and most notably a divergent RNA binding protein RBP5, indicative of a non-canonical mechanism for regulating intracellular iron levels. We show that cells depleted of TfR by RNA silencing import free iron as a compensatory survival strategy. The TfR and RBP5 iron response are reversible by genetic complementation, the response kinetics are similar, but the regulatory mechanisms are distinct. Increased TfR protein is due to increased mRNA. Increased RBP5 expression, however, occurs by a post-transcriptional feedback mechanism whereby RBP5 interacts with its own, and with PAP2 mRNAs. Further observations suggest that increased RBP5 expression in iron-deprived cells has a maximum threshold as ectopic overexpression above this threshold disrupts normal cell cycle progression resulting in an accumulation of anucleate cells and cells in G2/M phase. This phenotype is not observed with overexpression of RPB5 containing a point mutation (F61A) in its single RNA Recognition Motif. Our experiments shed new light on how T. brucei BSFs reorganise their transcriptome to deal with iron stress revealing the first iron responsive RNA binding protein that is co-regulated with TfR, is important for cell viability and iron homeostasis; two essential processes for successful proliferation.
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Affiliation(s)
- Carla Gilabert Carbajo
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London, United Kingdom
| | - Lucy J. Cornell
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London, United Kingdom
| | - Youssef Madbouly
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London, United Kingdom
| | - Zhihao Lai
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London, United Kingdom
| | - Phillip A. Yates
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Michele Tinti
- Wellcome Trust Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Calvin Tiengwe
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London, United Kingdom
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11
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Maciver SK, McLaughlin PJ, Apps DK, Piñero JE, Lorenzo-Morales J. Opinion: Iron, Climate Change and the ‘Brain Eating Amoeba’ Naegleria fowleri. Protist 2021. [DOI: 10.1016/j.protis.2020.125791] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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12
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Gawryluk RMR, Stairs CW. Diversity of electron transport chains in anaerobic protists. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1862:148334. [PMID: 33159845 DOI: 10.1016/j.bbabio.2020.148334] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/21/2020] [Accepted: 10/30/2020] [Indexed: 01/06/2023]
Abstract
Eukaryotic microbes (protists) that occupy low-oxygen environments often have drastically different mitochondrial metabolism compared to their aerobic relatives. A common theme among many anaerobic protists is the serial loss of components of the electron transport chain (ETC). Here, we discuss the diversity of the ETC across the tree of eukaryotes and review hypotheses for how ETCs are modified, and ultimately lost, in protists. We find that while protists have converged to some of the same metabolism as anaerobic animals, there are clear protist-specific strategies to thrive without oxygen.
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Affiliation(s)
- Ryan M R Gawryluk
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Courtney W Stairs
- Department of Biology, Lund University, Sölvegatan 35, 223 62 Lund, Sweden; Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, SE-75123 Uppsala, Sweden.
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Grechnikova M, Ženíšková K, Malych R, Mach J, Sutak R. Copper detoxification machinery of the brain-eating amoeba Naegleria fowleri involves copper-translocating ATPase and the antioxidant system. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2020; 14:126-135. [PMID: 33096396 PMCID: PMC7578549 DOI: 10.1016/j.ijpddr.2020.10.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 09/29/2020] [Accepted: 10/02/2020] [Indexed: 11/19/2022]
Abstract
Copper is a trace metal that is necessary for all organisms but toxic when present in excess. Different mechanisms to avoid copper toxicity have been reported to date in pathogenic organisms such as Cryptococcus neoformans and Candida albicans. However, little if anything is known about pathogenic protozoans despite their importance in human and veterinary medicine. Naegleria fowleri is a free-living amoeba that occurs naturally in warm fresh water and can cause a rapid and deadly brain infection called primary amoebic meningoencephalitis (PAM). Here, we describe the mechanisms employed by N. fowleri to tolerate high copper concentrations, which include various strategies such as copper efflux mediated by a copper-translocating ATPase and upregulation of the expression of antioxidant enzymes and obscure hemerythrin-like and protoglobin-like proteins. The combination of different mechanisms efficiently protects the cell and ensures its high copper tolerance, which can be advantageous both in the natural environment and in the host. Nevertheless, we demonstrate that copper ionophores are potent antiamoebic agents; thus, copper metabolism may be considered a therapeutic target. N. fowleri employs the combination of copper efflux and antioxidant system to ensure a high copper tolerance. Copper efflux in N. fowleri is mediated by a copper-translocating P-type ATPase. Copper ionophores have amoebicidal effect against N. fowleri and thus may be potentially used as antiamoebic agents. Iron-binding proteins hemerythrin and protoglobin are highly upregulated in N. fowleri under copper overload.
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Affiliation(s)
- Maria Grechnikova
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Kateřina Ženíšková
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Ronald Malych
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Jan Mach
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Robert Sutak
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic.
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Mach J, Sutak R. Iron in parasitic protists – from uptake to storage and where we can interfere. Metallomics 2020; 12:1335-1347. [DOI: 10.1039/d0mt00125b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A comprehensive review of iron metabolism in parasitic protists and its potential use as a drug target.
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Affiliation(s)
- Jan Mach
- Department of Parasitology
- Faculty of Science - BIOCEV
- Charles University
- Vestec u Prahy
- Czech Republic
| | - Robert Sutak
- Department of Parasitology
- Faculty of Science - BIOCEV
- Charles University
- Vestec u Prahy
- Czech Republic
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