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Kuhlmann FM, Key PN, Hickerson SM, Turk J, Hsu FF, Beverley SM. Inositol phosphorylceramide synthase null Leishmania are viable and virulent in animal infections where salvage of host sphingomyelin predominates. J Biol Chem 2022; 298:102522. [PMID: 36162499 PMCID: PMC9637897 DOI: 10.1016/j.jbc.2022.102522] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 09/14/2022] [Accepted: 09/16/2022] [Indexed: 12/03/2022] Open
Abstract
Many pathogens synthesize inositol phosphorylceramide (IPC) as the major sphingolipid (SL), differing from the mammalian host where sphingomyelin (SM) or more complex SLs predominate. The divergence between IPC synthase and mammalian SL synthases has prompted interest as a potential drug target. However, in the trypanosomatid protozoan Leishmania, cultured insect stage promastigotes lack de novo SL synthesis (Δspt2-) and SLs survive and remain virulent, as infective amastigotes salvage host SLs and continue to produce IPC. To further understand the role of IPC, we generated null IPCS mutants in Leishmania major (Δipcs-). Unexpectedly and unlike fungi where IPCS is essential, Δipcs- was remarkably normal in culture and highly virulent in mouse infections. Both IPCS activity and IPC were absent in Δipcs- promastigotes and amastigotes, arguing against an alternative route of IPC synthesis. Notably, salvaged mammalian SM was highly abundant in purified amastigotes from both WT and Δipcs-, and salvaged SLs could be further metabolized into IPC. SM was about 7-fold more abundant than IPC in WT amastigotes, establishing that SM is the dominant amastigote SL, thereby rendering IPC partially redundant. These data suggest that SM salvage likely plays key roles in the survival and virulence of both WT and Δipcs- parasites in the infected host, confirmation of which will require the development of methods or mutants deficient in host SL/SM uptake in the future. Our findings call into question the suitability of IPCS as a target for chemotherapy, instead suggesting that approaches targeting SM/SL uptake or catabolism may warrant further emphasis.
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Affiliation(s)
- F. Matthew Kuhlmann
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, USA,Department of Internal Medicine, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Phillip N. Key
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Suzanne M. Hickerson
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - John Turk
- Department of Internal Medicine, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Fong-Fu Hsu
- Department of Internal Medicine, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Stephen M. Beverley
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, USA,For correspondence: Stephen M. Beverley
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Teixeira SC, da Silva MS, Gomes AAS, Moretti NS, Lopes DS, Ferro EAV, Rodrigues VDM. Panacea within a Pandora's box: the antiparasitic effects of phospholipases A 2 (PLA 2s) from snake venoms. Trends Parasitol 2021; 38:80-94. [PMID: 34364805 DOI: 10.1016/j.pt.2021.07.004] [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: 04/04/2021] [Revised: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 10/20/2022]
Abstract
Parasitic diseases affect millions of individuals worldwide, mainly in low-income regions. There is no cure for most of these diseases, and the treatment relies on drugs that have side effects and lead to drug resistance, emphasizing the urgency to find new treatments. Snake venom has been gaining prominence as a rich source of molecules with antiparasitic potentials, such as phospholipases A2 (PLA2s). Here, we compile the findings involving PLA2s with antiparasitic activities against helminths, Plasmodium, Toxoplasma, and trypanosomatids. We indicate their molecular features, highlighting the possible antiparasitic mechanisms of action of these proteins. We also demonstrate interactions between PLA2s and some parasite membrane components, shedding light on potential targets for drug design that may provide better treatment for the illnesses caused by parasites.
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Affiliation(s)
- Samuel Cota Teixeira
- Department of Immunology, Institute of Biomedical Science, Federal University of Uberlândia, Uberlândia (UFU), MG, Brazil.
| | - Marcelo Santos da Silva
- DNA Replication and Repair Laboratory (DRRL), Department of Chemical and Biological Sciences, Biosciences Institute, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | | | - Nilmar Silvio Moretti
- Laboratório de Biologia Molecular de Patógenos (LBMP), Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Daiana Silva Lopes
- Multidisciplinary Institute of Health, Anísio Teixeira Campus, Federal University of Bahia (UFBA), Vitória da Conquista, BA, Brazil
| | - Eloisa Amália Vieira Ferro
- Department of Immunology, Institute of Biomedical Science, Federal University of Uberlândia, Uberlândia (UFU), MG, Brazil
| | - Veridiana de Melo Rodrigues
- Laboratory of Biochemistry and Animal Toxins, Institute of Biotechnology, Federal University of Uberlândia (UFU), Uberlândia, MG, Brazil.
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3
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Ceramide Metabolism Enzymes-Therapeutic Targets against Cancer. ACTA ACUST UNITED AC 2021; 57:medicina57070729. [PMID: 34357010 PMCID: PMC8303233 DOI: 10.3390/medicina57070729] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 07/07/2021] [Accepted: 07/13/2021] [Indexed: 12/12/2022]
Abstract
Sphingolipids are both structural molecules that are essential for cell architecture and second messengers that are involved in numerous cell functions. Ceramide is the central hub of sphingolipid metabolism. In addition to being the precursor of complex sphingolipids, ceramides induce cell cycle arrest and promote cell death and inflammation. At least some of the enzymes involved in the regulation of sphingolipid metabolism are altered in carcinogenesis, and some are targets for anticancer drugs. A number of scientific reports have shown how alterations in sphingolipid pools can affect cell proliferation, survival and migration. Determination of sphingolipid levels and the regulation of the enzymes that are implicated in their metabolism is a key factor for developing novel therapeutic strategies or improving conventional therapies. The present review highlights the importance of bioactive sphingolipids and their regulatory enzymes as targets for therapeutic interventions with especial emphasis in carcinogenesis and cancer dissemination.
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Carmona-Salazar L, Cahoon RE, Gasca-Pineda J, González-Solís A, Vera-Estrella R, Treviño V, Cahoon EB, Gavilanes-Ruiz M. Plasma and vacuolar membrane sphingolipidomes: composition and insights on the role of main molecular species. PLANT PHYSIOLOGY 2021; 186:624-639. [PMID: 33570616 PMCID: PMC8154057 DOI: 10.1093/plphys/kiab064] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 01/24/2021] [Indexed: 05/04/2023]
Abstract
Lipid structures affect membrane biophysical properties such as thickness, stability, permeability, curvature, fluidity, asymmetry, and interdigitation, contributing to membrane function. Sphingolipids are abundant in plant endomembranes and plasma membranes (PMs) and comprise four classes: ceramides, hydroxyceramides, glucosylceramides, and glycosylinositolphosphoceramides (GIPCs). They constitute an array of chemical structures whose distribution in plant membranes is unknown. With the aim of describing the hydrophobic portion of sphingolipids, 18 preparations from microsomal (MIC), vacuolar (VM), PM, and detergent-resistant membranes (DRM) were isolated from Arabidopsis (Arabidopsis thaliana) leaves. Sphingolipid species, encompassing pairing of long-chain bases and fatty acids, were identified and quantified in these membranes. Sphingolipid concentrations were compared using univariate and multivariate analysis to assess sphingolipid diversity, abundance, and predominance across membranes. The four sphingolipid classes were present at different levels in each membrane: VM was enriched in glucosylceramides, hydroxyceramides, and GIPCs; PM in GIPCs, in agreement with their key role in signal recognition and sensing; and DRM in GIPCs, as reported by their function in nanodomain formation. While a total of 84 sphingolipid species was identified in MIC, VM, PM, and DRM, only 34 were selectively distributed in the four membrane types. Conversely, every membrane contained a different number of predominant species (11 in VM, 6 in PM, and 17 in DRM). This study reveals that MIC, VM, PM, and DRM contain the same set of sphingolipid species but every membrane source contains its own specific assortment based on the proportion of sphingolipid classes and on the predominance of individual species.
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Affiliation(s)
- Laura Carmona-Salazar
- Dpto. de Bioquímica, Facultad de Química, Conj. E. Universidad Nacional Autónoma de México, UNAM. Cd. Universitaria, Coyoacán. 04510, Cd. de México, México
| | - Rebecca E Cahoon
- Center for Plant Science Innovation & Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, NE 68588–0665, USA
| | - Jaime Gasca-Pineda
- UBIPRO, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, UNAM, 54090, Estado de México, México
| | - Ariadna González-Solís
- Center for Plant Science Innovation & Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, NE 68588–0665, USA
| | - Rosario Vera-Estrella
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, UNAM. Cuernavaca, Morelos, México
| | - Victor Treviño
- Tecnológico de Monterrey, Escuela de Medicina, 64710 Monterrey, Nuevo León, México
| | - Edgar B Cahoon
- Center for Plant Science Innovation & Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, NE 68588–0665, USA
| | - Marina Gavilanes-Ruiz
- Dpto. de Bioquímica, Facultad de Química, Conj. E. Universidad Nacional Autónoma de México, UNAM. Cd. Universitaria, Coyoacán. 04510, Cd. de México, México
- Author for communication:
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5
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Rocha-Hasler M, de Oliveira GM, da Gama AN, Fiuza LFDA, Fesser AF, Cal M, Rocchetti R, Peres RB, Guan XL, Kaiser M, Soeiro MDNC, Mäser P. Combination With Tomatidine Improves the Potency of Posaconazole Against Trypanosoma cruzi. Front Cell Infect Microbiol 2021; 11:617917. [PMID: 33747979 PMCID: PMC7970121 DOI: 10.3389/fcimb.2021.617917] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 01/15/2021] [Indexed: 11/23/2022] Open
Abstract
Azoles such as posaconazole (Posa) are highly potent against Trypanosoma cruzi. However, when tested in chronic Chagas disease patients, a high rate of relapse after Posa treatment was observed. It appears that inhibition of T. cruzi cytochrome CYP51, the target of azoles, does not deliver sterile cure in monotherapy. Looking for suitable combination partners of azoles, we have selected a set of inhibitors of sterol and sphingolipid biosynthetic enzymes. A small-scale phenotypic screening was conducted in vitro against the proliferative forms of T. cruzi, extracellular epimastigotes and intracellular amastigotes. Against the intracellular, clinically relevant forms, four out of 15 tested compounds presented higher or equal activity as benznidazole (Bz), with EC50 values ≤2.2 μM. Ro48-8071, an inhibitor of lanosterol synthase (ERG7), and the steroidal alkaloid tomatidine (TH), an inhibitor of C-24 sterol methyltransferase (ERG6), exhibited the highest potency and selectivity indices (SI = 12 and 115, respectively). Both were directed to combinatory assays using fixed-ratio protocols with Posa, Bz, and fexinidazole. The combination of TH with Posa displayed a synergistic profile against amastigotes, with a mean ΣFICI value of 0.2. In vivo assays using an acute mouse model of T. cruzi infection demonstrated lack of antiparasitic activity of TH alone in doses ranging from 0.5 to 5 mg/kg. As observed in vitro, the best combo proportion in vivo was the ratio 3 TH:1 Posa. The combination of Posa at 1.25 mpk plus TH at 3.75 mpk displayed suppression of peak parasitemia of 80% and a survival rate of 60% in the acute infection model, as compared to 20% survival for Posa at 1.25 mpk alone and 40% for Posa at 10 mpk alone. These initial results indicate a potential for the combination of posaconazole with tomatidine against T. cruzi.
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Affiliation(s)
- Marianne Rocha-Hasler
- Laboratório de Biologia Celular, Instituto Oswaldo Cruz (IOC/Fiocruz), Pavilhão Cardoso Fontes, Rio de Janeiro, Brazil.,Parasite Chemotherapy Unit, Swiss Tropical and Public Health Institute, Medical Parasitology and Infection Biology, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Gabriel Melo de Oliveira
- Laboratório de Biologia Celular, Instituto Oswaldo Cruz (IOC/Fiocruz), Pavilhão Cardoso Fontes, Rio de Janeiro, Brazil
| | - Aline Nefertiti da Gama
- Laboratório de Biologia Celular, Instituto Oswaldo Cruz (IOC/Fiocruz), Pavilhão Cardoso Fontes, Rio de Janeiro, Brazil
| | | | - Anna Frieda Fesser
- Parasite Chemotherapy Unit, Swiss Tropical and Public Health Institute, Medical Parasitology and Infection Biology, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Monica Cal
- Parasite Chemotherapy Unit, Swiss Tropical and Public Health Institute, Medical Parasitology and Infection Biology, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Romina Rocchetti
- Parasite Chemotherapy Unit, Swiss Tropical and Public Health Institute, Medical Parasitology and Infection Biology, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Raiza Brandão Peres
- Laboratório de Biologia Celular, Instituto Oswaldo Cruz (IOC/Fiocruz), Pavilhão Cardoso Fontes, Rio de Janeiro, Brazil
| | - Xue Li Guan
- Systems Biology of Lipid Metabolism in Human Health and Diseases Laboratory, Lee Kong Chian School of Medicine, Singapore, Singapore
| | - Marcel Kaiser
- Parasite Chemotherapy Unit, Swiss Tropical and Public Health Institute, Medical Parasitology and Infection Biology, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | | | - Pascal Mäser
- Parasite Chemotherapy Unit, Swiss Tropical and Public Health Institute, Medical Parasitology and Infection Biology, Basel, Switzerland.,University of Basel, Basel, Switzerland
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6
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Hsu FF. Electrospray ionization with higher-energy collision dissociation tandem mass spectrometry toward characterization of ceramides as [M + Li] + ions: Mechanisms of fragmentation and structural identification. Anal Chim Acta 2021; 1142:221-234. [PMID: 33280700 DOI: 10.1016/j.aca.2020.09.056] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 09/14/2020] [Accepted: 09/25/2020] [Indexed: 12/23/2022]
Abstract
Ceramide is a huge lipid family consisting of diversified structures in which various modifications are seen in the fatty acyl chain and the long chain base (LCB). In this contribution, a higher collision energy (HCD) linear ion-trap mass spectrometric method (LIT MSn) was applied to study the mechanisms underlying the fragmentation processes of ceramide molecules in 12 subclasses, which were desorbed by ESI as the [M + Li]+ ions. Multiple sets of fragment ions reflecting the fatty acyl chain and LCB were observed in the HCD MS2 spectra for all the ceramide classes, resulting in unambiguous definition of the ceramide structures, including the chain length and the modification (α-hydroxy-, β-hydroxy-, ω-hydroxy-FA) of the fatty acyl moiety, and the types of LCB (sphingosine, phytosphigosine, 6-hydroxy-sphingosine). Thereby, this approach permits differentiation of isomeric structures and ceramide species in the biological specimen can be unveiled in detail. By application of sequential MS3, the double bond position along the fatty acyl chain of the molecule can be located, and a complete structural characterization of ceramides can be achieved.
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Affiliation(s)
- Fong-Fu Hsu
- Mass Spectrometry Resource, Division of Endocrinology, Diabetes, Metabolism, and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63130, USA.
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7
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Booth LA, Smith TK. Lipid metabolism in Trypanosoma cruzi: A review. Mol Biochem Parasitol 2020; 240:111324. [PMID: 32961207 DOI: 10.1016/j.molbiopara.2020.111324] [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: 06/30/2020] [Revised: 09/02/2020] [Accepted: 09/11/2020] [Indexed: 01/08/2023]
Abstract
The cellular membranes of Trypanosoma cruzi, like all eukaryotes, contain varying amounts of phospholipids, sphingolipids, neutral lipids and sterols. A multitude of pathways exist for the de novo synthesis of these lipid families but Trypanosoma cruzi has also become adapted to scavenge some of these lipids from the host. Completion of the TriTryp genomes has led to the identification of many putative genes involved in lipid synthesis, revealing some interesting differences to higher eukaryotes. Although many enzymes involved in lipid synthesis have yet to be characterised, completed experiments have shown the indispensability of some lipid metabolic pathways. Furthermore, the bioactive lipids of Trypanosoma cruzi and their effects on the host are becoming increasingly studied. Further studies on lipid metabolism in Trypanosoma cruzi will no doubt reveal some attractive targets for therapeutic intervention as well as reveal the interplay between parasite lipids, host response and pathogenesis.
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Affiliation(s)
- Leigh-Ann Booth
- Biomedical Sciences Research Complex, University of St Andrews, North Haugh, St Andrews, Scotland, KY16 9ST, United Kingdom
| | - Terry K Smith
- Biomedical Sciences Research Complex, University of St Andrews, North Haugh, St Andrews, Scotland, KY16 9ST, United Kingdom.
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8
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Lysophosphatidylcholine triggers cell differentiation in the protozoan parasite Herpetomonas samuelpessoai through the CK2 pathway. Acta Parasitol 2020; 65:108-117. [PMID: 31755068 DOI: 10.2478/s11686-019-00135-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 10/03/2019] [Indexed: 12/30/2022]
Abstract
BACKGROUND Protozoa are distantly related to vertebrates but present some features of higher eukaryotes, making them good model systems for studying the evolution of basic processes such as the cell cycle. Herpetomonas samuelpessoai is a trypanosomatid parasite isolated from the hemipteran insect Zelus leucogrammus. Lysophosphatidylcholine (LPC) is implicated in the transmission and establishment of Chagas disease, whose etiological agent is Trypanosoma cruzi. LPC is synthesized by T. cruzi and its vectors, the hemipteran Rhodnius prolixus and Triatoma infestans. Platelet-activating factor (PAF), a phospholipid with potent and diverse physiological and pathophysiological actions, is a powerful inducer of cell differentiation in Herpetomonas muscarum muscarum and T. cruzi. The enzyme phospholipase A2 (PLA2) catalyzes the hydrolysis of the 2-ester bond of 3-sn-phosphoglyceride, transforming phosphatidylcholine (PC) into LPC. METHODS In this study, we evaluated cellular differentiation, PLA2 activity and protein kinase CK2 activity of H. samuelpessoai in the absence and in the presence of LPC and PAF. RESULTS We demonstrate that both PC and LPC promoted a twofold increase in the cellular differentiation of H. samuelpessoai, through CK2, with a concomitant inhibition of its cell growth. Intrinsic PLA2 most likely directs this process by converting PC into LPC. CONCLUSIONS Our results suggest that the actions of LPC on H. samuelpessoai occur upon binding to a putative PAF receptor and that the protein kinase CK2 plays a major role in this process. Cartoon depicting a model for the synthesis and functions of LPC in Herpetomonas samuelpessoai, based upon our results regarding the role of LPC on the cell biology of Trypanosoma cruzi [28-32]. N nucleus, k kinetoplast, PC phosphatidylcholine, LPC lysophosphatidylcholine, PLA2 phospholipase A2, PAFR putative PAF receptor in trypanosomatids [65], CK2 protein kinase CK2 [16].
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Hennig K, Abi-Ghanem J, Bunescu A, Meniche X, Biliaut E, Ouattara AD, Lewis MD, Kelly JM, Braillard S, Courtemanche G, Chatelain E, Béquet F. Metabolomics, lipidomics and proteomics profiling of myoblasts infected with Trypanosoma cruzi after treatment with different drugs against Chagas disease. Metabolomics 2019; 15:117. [PMID: 31440849 DOI: 10.1007/s11306-019-1583-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 08/17/2019] [Indexed: 01/11/2023]
Abstract
INTRODUCTION Chagas disease, the most important parasitic infection in Latin America, is caused by the intracellular protozoan Trypanosoma cruzi. To treat this disease, only two nitroheterocyclic compounds with toxic side effects exist and frequent treatment failures are reported. Hence there is an urgent need to develop new drugs. Recently, metabolomics has become an efficient and cost-effective strategy for dissecting drug mode of action, which has been applied to bacteria as well as parasites, such as different Trypanosome species and forms. OBJECTIVES We assessed if the metabolomics approach can be applied to study drug action of the intracellular amastigote form of T. cruzi in a parasite-host cell system. METHODS We applied a metabolic fingerprinting approach (DI-MS and NMR) to evaluate metabolic changes induced by six different (candidate) drugs in a parasite-host cell system. In a second part of our study, we analyzed the impact of two drugs on polar metabolites, lipid and proteins to evaluate if affected pathways can be identified. RESULTS Metabolic signatures, obtained by the fingerprinting approach, resulted in three different clusters. Two can be explained by already known of mode actions, whereas the three experimental drugs formed a separate cluster. Significant changes induced by drug action were observed in all the three metabolic fractions (polar metabolites, lipids and proteins). We identified a general impact on the TCA cycle, but no specific pathways could be attributed to drug action, which might be caused by a high percentage of common metabolome between a eukaryotic host cell and a eukaryotic parasite. Additionally, ion suppression effects due to differences in abundance between host cells and parasites may have occurred. CONCLUSION We validated the metabolic fingerprinting approach to a complex host-cell parasite system. This technique can potentially be applied in the early stage of drug discovery and could help to prioritize early leads or reconfirmed hits for further development.
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Affiliation(s)
- K Hennig
- BIOASTER, 40 avenue Tony Garnier, 69007, Lyon, France
| | - J Abi-Ghanem
- BIOASTER, 40 avenue Tony Garnier, 69007, Lyon, France
| | - A Bunescu
- BIOASTER, 40 avenue Tony Garnier, 69007, Lyon, France
| | - X Meniche
- BIOASTER, 40 avenue Tony Garnier, 69007, Lyon, France
| | - E Biliaut
- BIOASTER, 40 avenue Tony Garnier, 69007, Lyon, France
| | - A D Ouattara
- BIOASTER, 40 avenue Tony Garnier, 69007, Lyon, France
| | - M D Lewis
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - J M Kelly
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - S Braillard
- Drugs for Neglected Diseases Initiative (DNDi), 15 Chemin Louis-Dunant, 1202, Geneva, Switzerland
| | | | - E Chatelain
- Drugs for Neglected Diseases Initiative (DNDi), 15 Chemin Louis-Dunant, 1202, Geneva, Switzerland
| | - F Béquet
- BIOASTER, 40 avenue Tony Garnier, 69007, Lyon, France.
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Abstract
The kinetoplastid parasite Trypanosoma brucei causes African trypanosomiasis in both humans and animals. Infections place a significant health and economic burden on developing nations in sub-Saharan Africa, but few effective anti-parasitic treatments are currently available. Hence, there is an urgent need to identify new leads for drug development. The T. brucei neutral sphingomyelinase (TbnSMase) was previously established as essential to parasite survival, consequently being identified as a potential drug target. This enzyme may catalyse the single route to sphingolipid catabolism outside the T. brucei lysosome. To obtain new insight into parasite sphingolipid catabolism, the substrate specificity of TbnSMase was investigated using electrospray ionization tandem mass spectrometry (ESI-MS/MS). Recombinant TbnSMase was shown to degrade sphingomyelin, inositol-phosphoceramide and ethanolamine-phosphoceramide sphingolipid substrates, consistent with the sphingolipid complement of the parasites. TbnSMase also catabolized ceramide-1-phosphate, but was inactive towards sphingosine-1-phosphate. The broad-range specificity of this enzyme towards sphingolipid species is a unique feature of TbnSMase. Additionally, ESI-MS/MS analysis revealed previously uncharacterized activity towards lyso-phosphatidylcholine despite the enzyme's inability to degrade phosphatidylcholine. Collectively, these data underline the enzyme's importance in choline homoeostasis and the turnover of sphingolipids in T. brucei.
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