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Millner A, Running L, Colon-Rosa N, Aga DS, Frasor J, Atilla-Gokcumen GE. Ceramide-1-Phosphate Is Involved in Therapy-Induced Senescence. ACS Chem Biol 2022; 17:822-828. [PMID: 35353506 DOI: 10.1021/acschembio.2c00216] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Sphingolipids are key signaling lipids and their dysregulation has been associated with various cellular processes. We have previously shown significant changes in sphingolipids in therapy-induced senescence, a state of cell cycle arrest as a response to chemotherapy, including the accumulation of ceramides, and provided evidence suggesting that ceramide processing is important for this process. Herein, we conducted a focused small molecule inhibitor screen targeting the sphingolipid pathway, which highlighted a new lipid regulator of therapy-induced senescence. Among the inhibitors tested, the inhibition of ceramide kinase by NVP-231 reduced the levels of senescent cells. Ceramide kinase knockdown exhibited similar effects, strongly supporting the involvement of ceramide kinase during this process. We showed that ceramide-1-phosphate was upregulated in therapy-induced senescence and that NVP-231 reduced ceramide-1-phosphate levels in different cell line models of therapy-induced senescence. Finally, ceramide-1-phosphate addition to NVP-231-treated cells reversed the effects of NVP-231 during senescence. Overall, our results identify a previously unknown lipid player in therapy-induced senescence and highlight a potential targetable enzyme to reduce the levels of therapy-induced senescent cells.
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Affiliation(s)
- Alec Millner
- Department of Chemistry, University at Buffalo, The State University of New York (SUNY), Buffalo, New York 14260, United States
| | - Logan Running
- Department of Chemistry, University at Buffalo, The State University of New York (SUNY), Buffalo, New York 14260, United States
| | - Nicole Colon-Rosa
- Department of Chemistry, University at Buffalo, The State University of New York (SUNY), Buffalo, New York 14260, United States
- Department of Chemistry, University of Puerto Rico, Cayey, 00736, Puerto Rico
| | - Diana S. Aga
- Department of Chemistry, University at Buffalo, The State University of New York (SUNY), Buffalo, New York 14260, United States
| | - Jonna Frasor
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, Illinois 60612, United States
| | - G. Ekin Atilla-Gokcumen
- Department of Chemistry, University at Buffalo, The State University of New York (SUNY), Buffalo, New York 14260, United States
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2
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Erythrocyte sphingosine kinase regulates intraerythrocytic development of Plasmodium falciparum. Sci Rep 2021; 11:1257. [PMID: 33441957 PMCID: PMC7806667 DOI: 10.1038/s41598-020-80658-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 10/26/2020] [Indexed: 11/18/2022] Open
Abstract
The sphingolipid pool is key regulator of vital cellular functions in Plasmodium falciparum a causative agent for deadly malaria. Erythrocytes, the host for asexual stage of Plasmodium, are major reservoir for Sphingosine-1-phosphate (S1P). Erythrocyte possesses Sphingosine kinase (SphK) that catalyzed its biosynthesis from sphingosine (Sph). Since, Plasmodium lacks SphK homologous protein it can be envisaged that it co-opts sphingolipids from both intraerythrocytic as well as extracellular pools for its growth and development. Herein, by sphingosine-NBD probing, we report that infected erythrocytes imports Sph from extracellular pool, which is converted to S1P and thereby taken by P. falciparum. Next, by targeting of the SphK through specific inhibitor N,N-Dimethylsphingosine DMS, we show a reduction in erythrocyte endogenous S1P pool and SphK-phosphorylation that led to inhibition in growth and development of ring stage P. falciparum. Owing to the role of S1P in erythrocyte glycolysis we analyzed uptake of NBD-Glucose and production of lactate in DMS treated and untreated plasmodium. DMS treatment led to decreased glycolysis in Plasmodium. Interestingly the host free Plasmodium did not show any effect on glycolysis with DMS treatment indicating its host-mediated effect. Further to understand the in-vivo anti-plasmodial effects of exogenous and endogenous erythrocyte S1P level, Sphingosine-1-phosphate lyase (S1PL) inhibitor (THI), S1P and SphK-1 inhibitor (DMS), were used in Plasmodium berghei ANKA (PbA) mice model. DMS treatment led to reduction of endogenous S1P conferred significant decrease in parasite load, whereas the plasma level S1P modulated by (THI) and exogenous S1P have no effect on growth of Plasmodium. This suggested erythrocyte endogenous S1P pool is important for Plasmodium growth whereas the plasma level S1P has no effect. Altogether, this study provides insight on cellular processes regulated by S1P in P. falciparum and highlights the novel mechanistically distinct molecular target i.e. SphK-1.
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Effect of tamoxifen on the sphingolipid biosynthetic pathway in the different intraerythrocytic stages of the apicomplexa Plasmodium falciparum. Biochem Biophys Res Commun 2018; 497:1082-1088. [PMID: 29496449 DOI: 10.1016/j.bbrc.2018.02.183] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 02/23/2018] [Indexed: 11/21/2022]
Abstract
Parasites of the genus Plasmodium responsible for Malaria are obligate intracellular pathogens residing in mammalian red blood cells, hepatocytes, or mosquito midgut epithelial cells. Regarding that detailed knowledge on the sphingolipid biosynthetic pathway of the apicomplexan protozoan parasites is scarce, different stages of Plasmodium falciparum were treated with tamoxifen in order to evaluate the effects of this drug on the glycosphingolipid biosynthesis. Thin layer chromatography, High performance reverse phase chromatography and UV-MALDI-TOF mass spectrometry were the tools used for the analysis. In the ring forms, the increase of NBD-phosphatidyl inositol biosynthesis was notorious but differences at NBD-GlcCer levels were undetectable. In trophozoite forms, an abrupt decrease of NBD-acylated GlcDHCer and NBD-GlcDHCer in addition to an increase of NBD-PC biosynthesis was observed. On the contrary, in schizonts, tamoxifen seems not to be producing substantial changes in lipid biosynthesis. Our findings indicate that in this parasite, tamoxifen is exerting an inhibitory action on Glucosylceramidesynthase and sphingomyelin synthase levels. Moreover, regarding that Plasmodium does not biosynthesize inositolphosphoceramides, the accumulation of phosphatidylinositol should indicate an inhibitory action on glycosylinositol phospholipid synthesis.
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Santi-Rocca J, Blanchard N. Membrane trafficking and remodeling at the host-parasite interface. Curr Opin Microbiol 2017; 40:145-151. [PMID: 29175340 DOI: 10.1016/j.mib.2017.11.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 10/14/2017] [Accepted: 11/13/2017] [Indexed: 11/16/2022]
Abstract
Membrane shape is functionally linked with many cellular processes. The limiting membrane of vacuoles containing Toxoplasma gondii and Plasmodium apicomplexan parasites lies at the host-parasite interface. This membrane comprises intra-vacuolar and extra-vacuolar tubulo-vesicular deformations, which influence host-parasite cross-talk. Here, underscoring specificities and similarities between the T. gondii and Plasmodium contexts, we present recent findings about vacuolar membrane remodeling and its potential roles in parasite fitness and immune recognition. We review in particular the implication of tubulo-vesicular structures in trapping and/or transporting host and parasite components. Understanding how membrane remodeling influences host-pathogen interactions is expected to be critical in the battle against many intracellular pathogens beyond parasites.
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Affiliation(s)
- Julien Santi-Rocca
- Centre de Physiopathologie de Toulouse Purpan (CPTP), INSERM, CNRS, Université de Toulouse, UPS, Toulouse, France
| | - Nicolas Blanchard
- Centre de Physiopathologie de Toulouse Purpan (CPTP), INSERM, CNRS, Université de Toulouse, UPS, Toulouse, France.
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5
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Mina JG, Thye JK, Alqaisi AQI, Bird LE, Dods RH, Grøftehauge MK, Mosely JA, Pratt S, Shams-Eldin H, Schwarz RT, Pohl E, Denny PW. Functional and phylogenetic evidence of a bacterial origin for the first enzyme in sphingolipid biosynthesis in a phylum of eukaryotic protozoan parasites. J Biol Chem 2017; 292:12208-12219. [PMID: 28578314 PMCID: PMC5519370 DOI: 10.1074/jbc.m117.792374] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 06/01/2017] [Indexed: 11/06/2022] Open
Abstract
Toxoplasma gondii is an obligate, intracellular eukaryotic apicomplexan protozoan parasite that can cause fetal damage and abortion in both animals and humans. Sphingolipids are essential and ubiquitous components of eukaryotic membranes that are both synthesized and scavenged by the Apicomplexa. Here we report the identification, isolation, and analyses of the Toxoplasma serine palmitoyltransferase, an enzyme catalyzing the first and rate-limiting step in sphingolipid biosynthesis: the condensation of serine and palmitoyl-CoA. In all eukaryotes analyzed to date, serine palmitoyltransferase is a highly conserved heterodimeric enzyme complex. However, biochemical and structural analyses demonstrated the apicomplexan orthologue to be a functional, homodimeric serine palmitoyltransferase localized to the endoplasmic reticulum. Furthermore, phylogenetic studies indicated that it was evolutionarily related to the prokaryotic serine palmitoyltransferase, identified in the Sphingomonadaceae as a soluble homodimeric enzyme. Therefore this enzyme, conserved throughout the Apicomplexa, is likely to have been obtained via lateral gene transfer from a prokaryote.
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Affiliation(s)
- John G Mina
- Department of Biosciences, Durham University, Durham DH1 3LE, United Kingdom
| | - Julie K Thye
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Amjed Q I Alqaisi
- Department of Biosciences, Durham University, Durham DH1 3LE, United Kingdom; Biology Department, College of Science, University of Baghdad, Baghdad 10071, Iraq
| | - Louise E Bird
- Oxford Protein Production Facility UK, Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot OX11 0FA, United Kingdom
| | - Robert H Dods
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | | | - Jackie A Mosely
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Steven Pratt
- Department of Biosciences, Durham University, Durham DH1 3LE, United Kingdom
| | - Hosam Shams-Eldin
- Institut für Virologie, Zentrum für Hygiene und Infektionsbiologie, Philipps-Universität Marburg, 35043 Marburg, Germany
| | - Ralph T Schwarz
- Institut für Virologie, Zentrum für Hygiene und Infektionsbiologie, Philipps-Universität Marburg, 35043 Marburg, Germany
| | - Ehmke Pohl
- Department of Biosciences, Durham University, Durham DH1 3LE, United Kingdom; Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Paul W Denny
- Department of Biosciences, Durham University, Durham DH1 3LE, United Kingdom.
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The antifungal Aureobasidin A and an analogue are active against the protozoan parasite Toxoplasma gondii but do not inhibit sphingolipid biosynthesis. Parasitology 2017; 145:148-155. [PMID: 28486997 PMCID: PMC5964465 DOI: 10.1017/s0031182017000506] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Toxoplasma gondii is an obligate intracellular protozoan parasite of the
phylum Apicomplexa, and toxoplasmosis is an important disease of both humans and
economically important animals. With a limited array of drugs available there is a need to
identify new therapeutic compounds. Aureobasidin A (AbA) is an antifungal that targets the
essential inositol phosphorylceramide (IPC, sphingolipid) synthase in pathogenic fungi.
This natural cyclic depsipeptide also inhibits Toxoplasma proliforation,
with the protozoan IPC synthase orthologue proposed as the target. The data presented here
show that neither AbA nor an analogue (Compound 20), target the protozoan IPC synthase
orthologue or total parasite sphingolipid synthesis. However, further analyses confirm
that AbA exhibits significant activity against the proliferative tachyzoite form of
Toxoplasma, and Compound 20, whilst effective, has reduced efficacy.
This difference was more evident on analyses of the direct effect of these compounds
against isolated Toxoplasma, indicating that AbA is rapidly microbicidal.
Importantly, the possibility of targeting the encysted, bradyzoite, form of the parasite
with AbA and Compound 20 was demonstrated, indicating that this class of compounds may
provide the basis for the first effective treatment for chronic toxoplasmosis.
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Lingelbach K. Protein trafficking in thePlasmodium-falciparum-infected erythrocyte—from models to mechanisms. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2016. [DOI: 10.1080/00034983.1997.11813172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Ebine K, Hirai M, Sakaguchi M, Yahata K, Kaneko O, Saito-Nakano Y. Plasmodium Rab5b is secreted to the cytoplasmic face of the tubovesicular network in infected red blood cells together with N-acylated adenylate kinase 2. Malar J 2016; 15:323. [PMID: 27316546 PMCID: PMC4912828 DOI: 10.1186/s12936-016-1377-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Accepted: 06/08/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Rab5 GTPase regulates membrane trafficking between the plasma membrane and endosomes and harbours a conserved C-terminal isoprenyl modification that is necessary for membrane recruitment. Plasmodium falciparum encodes three Rab5 isotypes, and one of these, Rab5b (PfRab5b), lacks the C-terminal modification but possesses the N-terminal myristoylation motif. PfRab5b was reported to localize to the parasite periphery. However, the trafficking pathway regulated by PfRab5b is unknown. METHODS A complementation analysis of Rab5 isotypes was performed in Plasmodium berghei. A constitutively active PfRab5b mutant was expressed under the regulation of a ligand-dependent destabilization domain (DD)-tag system in P. falciparum. The localization of PfRab5b was evaluated after removing the ligand followed by selective permeabilization of the membrane with different detergents. Furthermore, P. falciparum N-terminally myristoylated adenylate kinase 2 (PfAK2) was co-expressed with PfRab5b, and trafficking of PfAK2 to the parasitophorous vacuole membrane was examined by confocal microscopy. RESULTS PfRab5b complemented the function of PbRab5b, however, the conventional C-terminally isoprenylated Rab5, PbRab5a or PbRab5c, did not. The constitutively active PfRab5b mutant localized to the cytosol of the parasite and the tubovesicular network (TVN), a region that extends from the parasitophorous vacuole membrane (PVM) in infected red blood cells (iRBCs). By removing the DD-ligand, parasite cytosolic PfRab5b signal disappeared and a punctate structure adjacent to the endoplasmic reticulum (ER) and parasite periphery accumulated. The peripheral PfRab5b was sensitive to extracellular proteolysis after treatment with streptolysin O, which selectively permeabilizes the red blood cell plasma membrane, indicating that PfRab5b localized on the iRBC cytoplasmic face of the TVN. Transport of PfAK2 to the PVM was abrogated by overexpression of PfRab5b, and PfAK2 accumulated in the punctate structure together with PfRab5b. CONCLUSION N-myristoylated Plasmodium Rab5b plays a role that is distinct from that of conventional mammalian Rab5 isotypes. PfRab5b localizes to a compartment close to the ER, translocated to the lumen of the organelle, and co-localizes with PfAK2. PfRab5b and PfAK2 are then transported to the TVN, and PfRab5b localizes on the iRBC cytoplasmic face of TVN. These data demonstrate that PfRab5b is transported from the parasite cytosol to TVN together with N-myristoylated PfAK2 via an uncharacterized membrane-trafficking pathway.
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Affiliation(s)
- Kazuo Ebine
- Department of Parasitology, National Institute of Infectious Diseases, Shinjuku-Ku, Tokyo, Japan. .,Division of Cellular Dynamics, National Institute for Basic Biology, Okazaki, Aichi, Japan.
| | - Makoto Hirai
- Department of Molecular and Cellular Parasitology, Graduate School of Medicine, Juntendo University, Bunkyo-Ku, Tokyo, Japan.,Department of Parasitology, Graduate School of Medicine, Gunma University, Gunma, Japan
| | - Miako Sakaguchi
- Central Laboratory, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Nagasaki, Japan
| | - Kazuhide Yahata
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Nagasaki, Japan
| | - Osamu Kaneko
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Nagasaki, Japan
| | - Yumiko Saito-Nakano
- Department of Parasitology, National Institute of Infectious Diseases, Shinjuku-Ku, Tokyo, Japan.
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9
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Tran PN, Brown SHJ, Rug M, Ridgway MC, Mitchell TW, Maier AG. Changes in lipid composition during sexual development of the malaria parasite Plasmodium falciparum. Malar J 2016; 15:73. [PMID: 26852399 PMCID: PMC4744411 DOI: 10.1186/s12936-016-1130-z] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 01/23/2016] [Indexed: 01/13/2023] Open
Abstract
Background The development of differentiated sexual stages (gametocytes) within human red blood cells is essential for the propagation of the malaria parasite, since only mature gametocytes will survive in the mosquito’s midgut. Hence gametocytogenesis is a pre-requisite for transmission of the disease. Physiological changes involved in sexual differentiation are still enigmatic. In particular the lipid metabolism—despite being central to cellular regulation and development—is not well explored. Methods Here the lipid profiles of red blood cells infected with the five different sexual stages of Plasmodium falciparum were analysed by mass spectrometry and compared to those from uninfected and asexual trophozoite infected erythrocytes. Results Fundamental differences between erythrocytes infected with the different parasite stages were revealed. In mature gametocytes many lipids that decrease in the trophozoite and early gametocyte infected red blood cells are regained. In particular, regulators of membrane fluidity, cholesterol and sphingomyelin, increased significantly during gametocyte maturation. Neutral lipids (serving mainly as caloriometric reserves) increased from 3 % of total lipids in uninfected to 27 % in stage V gametocyte infected red blood cells. The major membrane lipid class (phospholipids) decreased during gametocyte development. Conclusions The lipid profiles of infected erythrocytes are characteristic for the particular parasite life cycle and maturity stages of gametocytes. The obtained lipid profiles are crucial in revealing the lipid metabolism of malaria parasites and identifying targets to interfere with this deadly disease. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1130-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Phuong N Tran
- Research School of Biology, The Australian National University, Canberra, ACT, Australia. .,La Trobe Institute of Molecular Science, La Trobe University, Melbourne, VIC, Australia.
| | - Simon H J Brown
- School of Medicine and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia.
| | - Melanie Rug
- Research School of Biology, The Australian National University, Canberra, ACT, Australia. .,Centre for Advanced Microscopy, The Australian National University, Canberra, ACT, Australia.
| | - Melanie C Ridgway
- Research School of Biology, The Australian National University, Canberra, ACT, Australia.
| | - Todd W Mitchell
- School of Medicine and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia.
| | - Alexander G Maier
- Research School of Biology, The Australian National University, Canberra, ACT, Australia.
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The Plasmodium berghei translocon of exported proteins reveals spatiotemporal dynamics of tubular extensions. Sci Rep 2015. [PMID: 26219962 PMCID: PMC4518229 DOI: 10.1038/srep12532] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The erythrocyte is an extraordinary host cell for intracellular pathogens and requires extensive remodelling to become permissive for infection. Malaria parasites modify their host red blood cells through protein export to acquire nutrients and evade immune responses. Endogenous fluorescent tagging of three signature proteins of the Plasmodium berghei translocon of exported proteins (PTEX), heat shock protein 101, exported protein 2 (EXP2), and PTEX88, revealed motile, tubular extensions of the parasitophorous vacuole that protrude from the parasite far into the red blood cell. EXP2 displays a more prominent presence at the periphery of the parasite, consistent with its proposed role in pore formation. The tubular compartment is most prominent during trophozoite growth. Distinct spatiotemporal expression of individual PTEX components during sporogony and liver-stage development indicates additional functions and tight regulation of the PTEX translocon during parasite life cycle progression. Together, live cell imaging and correlative light and electron microscopy permitted previously unrecognized spatiotemporal and subcellular resolution of PTEX-containing tubules in murine malaria parasites. These findings further refine current models for Plasmodium-induced erythrocyte makeover.
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Legarda-Ceballos AL, del Olmo E, López-Abán J, Escarcena R, Bustos LA, Fonseca-Berzal C, Gómez-Barrio A, Dib JC, San Feliciano A, Muro A. Trypanocidal Activity of Long Chain Diamines and Aminoalcohols. Molecules 2015; 20:11554-68. [PMID: 26111182 PMCID: PMC6272662 DOI: 10.3390/molecules200611554] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 06/16/2015] [Accepted: 06/17/2015] [Indexed: 01/22/2023] Open
Abstract
Thirteen aminoalcohols and eight diamines were obtained and tested against Trypanosoma cruzi epimastigotes strains MG, JEM and CL-B5 clone. Some of them were equal or more potent (1.0–6.6 times) than the reference compound nifurtimox. From them, three aminoalcohols and two diamines were selected for amastigotes assays. Compound 5 was as potent as the reference drug nifurtimox against amastigotes of the CL-B5 strain (IC50 = 0.6 µM), with a selectivity index of 54.
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Affiliation(s)
- Ana L Legarda-Ceballos
- Laboratory of Molecular Immunology and Parasitology, Faculty of Pharmacy, CIETUS, IBSAL, Universidad de Salamanca, 37007-Salamanca, Spain.
| | - Esther del Olmo
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, CIETUS, IBSAL, Universidad de Salamanca, 37007-Salamanca, Spain.
| | - Julio López-Abán
- Laboratory of Molecular Immunology and Parasitology, Faculty of Pharmacy, CIETUS, IBSAL, Universidad de Salamanca, 37007-Salamanca, Spain.
| | - Ricardo Escarcena
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, CIETUS, IBSAL, Universidad de Salamanca, 37007-Salamanca, Spain.
| | - Luis A Bustos
- Department of Pharmaceutical Sciences, Faculty of Sciences, Catholic University of the North, 0610-Antofagasta, Chile.
| | - Cristina Fonseca-Berzal
- Department of Parasitology, Faculty of Pharmacy, Complutense University of Madrid (CEI Campus Moncloa, UCM-UPM & CSIC), 28040-Madrid, Spain.
| | - Alicia Gómez-Barrio
- Department of Parasitology, Faculty of Pharmacy, Complutense University of Madrid (CEI Campus Moncloa, UCM-UPM & CSIC), 28040-Madrid, Spain.
| | - Juan C Dib
- Research Center on Health for the Tropics, (CIST), Carretera Troncal del Caribe, Sector Mamatoco, Santa Marta, Magdalena, Colombia.
| | - Arturo San Feliciano
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, CIETUS, IBSAL, Universidad de Salamanca, 37007-Salamanca, Spain.
| | - Antonio Muro
- Laboratory of Molecular Immunology and Parasitology, Faculty of Pharmacy, CIETUS, IBSAL, Universidad de Salamanca, 37007-Salamanca, Spain.
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Plano D, Amin S, Sharma AK. Importance of sphingosine kinase (SphK) as a target in developing cancer therapeutics and recent developments in the synthesis of novel SphK inhibitors. J Med Chem 2014; 57:5509-24. [PMID: 24471412 DOI: 10.1021/jm4011687] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Sphingosine kinase (SphK) is an oncogenic lipid kinase that regulates the sphingolipid metabolic pathway that has been shown to play a role in numerous hyperproliferative/inflammatory diseases. The SphK isoforms (SphK1 and SphK2) catalyze the conversion of the proapoptotic substrate d-erythrosphingosine to the promitogenic/migratory product sphingosine 1-phosphate (S1P). Accumulation of S1P has been linked to the development/progression of cancer and various other diseases including, but not limited to, asthma, inflammatory bowel disease, rheumatoid arthritis, and diabetic nephropathy. SphK therefore represents a potential new target for developing novel therapeutics for cancer and other diseases. This finding has stimulated the development and evaluation of numerous SphK inhibitors over the past decade or so. In this review, we highlight the recent advancement in the field of SphK inhibitors including SphK1 and SphK2 specific inhibitors. Both sphingolipid based and nolipidic small molecule inhibitors and their importance in treatment of cancer and other diseases are discussed.
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Affiliation(s)
- Daniel Plano
- Department of Pharmacology, Penn State Hershey Cancer Institute, CH72, Penn State College of Medicine , 500 University Drive, Hershey, Pennsylvania 17033, United States
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Lipid synthesis in protozoan parasites: a comparison between kinetoplastids and apicomplexans. Prog Lipid Res 2013; 52:488-512. [PMID: 23827884 DOI: 10.1016/j.plipres.2013.06.003] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 06/16/2013] [Accepted: 06/17/2013] [Indexed: 12/22/2022]
Abstract
Lipid metabolism is of crucial importance for pathogens. Lipids serve as cellular building blocks, signalling molecules, energy stores, posttranslational modifiers, and pathogenesis factors. Parasites rely on a complex system of uptake and synthesis mechanisms to satisfy their lipid needs. The parameters of this system change dramatically as the parasite transits through the various stages of its life cycle. Here we discuss the tremendous recent advances that have been made in the understanding of the synthesis and uptake pathways for fatty acids and phospholipids in apicomplexan and kinetoplastid parasites, including Plasmodium, Toxoplasma, Cryptosporidium, Trypanosoma and Leishmania. Lipid synthesis differs in significant ways between parasites from both phyla and the human host. Parasites have acquired novel pathways through endosymbiosis, as in the case of the apicoplast, have dramatically reshaped substrate and product profiles, and have evolved specialized lipids to interact with or manipulate the host. These differences potentially provide opportunities for drug development. We outline the lipid pathways for key species in detail as they progress through the developmental cycle and highlight those that are of particular importance to the biology of the pathogens and/or are the most promising targets for parasite-specific treatment.
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Hullin-Matsuda F, Tomishige N, Sakai S, Ishitsuka R, Ishii K, Makino A, Greimel P, Abe M, Laviad EL, Lagarde M, Vidal H, Saito T, Osada H, Hanada K, Futerman AH, Kobayashi T. Limonoid compounds inhibit sphingomyelin biosynthesis by preventing CERT protein-dependent extraction of ceramides from the endoplasmic reticulum. J Biol Chem 2012; 287:24397-411. [PMID: 22605339 DOI: 10.1074/jbc.m112.344432] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To identify novel inhibitors of sphingomyelin (SM) metabolism, a new and selective high throughput microscopy-based screening based on the toxicity of the SM-specific toxin, lysenin, was developed. Out of a library of 2011 natural compounds, the limonoid, 3-chloro-8β-hydroxycarapin-3,8-hemiacetal (CHC), rendered cells resistant to lysenin by decreasing cell surface SM. CHC treatment selectively inhibited the de novo biosynthesis of SM without affecting glycolipid and glycerophospholipid biosynthesis. Pretreatment with brefeldin A abolished the limonoid-induced inhibition of SM synthesis suggesting that the transport of ceramide (Cer) from the endoplasmic reticulum to the Golgi apparatus is affected. Unlike the Cer transporter (CERT) inhibitor HPA-12, CHC did not change the transport of a fluorescent short chain Cer analog to the Golgi apparatus or the formation of fluorescent and short chain SM from the corresponding Cer. Nevertheless, CHC inhibited the conversion of de novo synthesized Cer to SM. We show that CHC specifically inhibited the CERT-mediated extraction of Cer from the endoplasmic reticulum membranes in vitro. Subsequent biochemical screening of 21 limonoids revealed that some of them, such as 8β-hydroxycarapin-3,8-hemiacetal and gedunin, which exhibits anti-cancer activity, inhibited SM biosynthesis and CERT-mediated extraction of Cer from membranes. Model membrane studies suggest that 8β-hydroxycarapin-3,8-hemiacetal reduced the miscibility of Cer with membrane lipids and thus induced the formation of Cer-rich membrane domains. Our study shows that certain limonoids are novel inhibitors of SM biosynthesis and suggests that some biological activities of these limonoids are related to their effect on the ceramide metabolism.
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Meyer EVS, Holt JJ, Girard KR, Ballie MT, Bushnev AS, Lapp S, Menaldino DS, Arrendale RF, Reddy GP, Evers TJ, Howard RB, Culver DG, Liotta DC, Galinski MR, Natchus MG. Sphingolipid analogues inhibit development of malaria parasites. ACS Med Chem Lett 2012; 3:43-7. [PMID: 24900369 DOI: 10.1021/ml2002136] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 12/06/2011] [Indexed: 11/28/2022] Open
Abstract
Plasmodium-infected erythrocytes have been shown to employ sphingolipids from both endogenous metabolism as well as existing host pools. Therapeutic agents that limit these supplies have thus emerged as intriguing, mechanistically distinct putative targets for the treatment of malaria infections. In an initial screen of our library of sphingolipid pathway modulators for efficacy against two strains of the predominant human malaria species Plasmodium falciparum and Plasmodium knowlesi, a series of orally available, 1-deoxysphingoid bases were found to possess promising in vitro antimalarial activity. To better understand the structural requirements that are necessary for this observed activity, a second series of modified analogues were prepared and evaluated. Initial pharmacokinetic assessments of key analogues were investigated to evaluate plasma and red blood cell concentrations in vivo.
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Affiliation(s)
- Esmeralda V. S. Meyer
- Emory Vaccine Center and Yerkes
National Primate Research Center, Emory University, Atlanta, Georgia 30329, United States
| | - Jason J. Holt
- Emory Institute for Drug Discovery (EIDD), 1515 Dickey Drive, Atlanta, Georgia
30322, United States
| | - Kathryn R. Girard
- Emory Vaccine Center and Yerkes
National Primate Research Center, Emory University, Atlanta, Georgia 30329, United States
| | - Mark T. Ballie
- Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia
30322, United States
| | - Anatoliy S. Bushnev
- Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia
30322, United States
| | - Stacey Lapp
- Emory Vaccine Center and Yerkes
National Primate Research Center, Emory University, Atlanta, Georgia 30329, United States
| | - David S. Menaldino
- Emory Institute for Drug Discovery (EIDD), 1515 Dickey Drive, Atlanta, Georgia
30322, United States
| | - Richard F. Arrendale
- Emory Institute for Drug Discovery (EIDD), 1515 Dickey Drive, Atlanta, Georgia
30322, United States
| | - G. Prabhakar Reddy
- Emory Institute for Drug Discovery (EIDD), 1515 Dickey Drive, Atlanta, Georgia
30322, United States
| | - Taylor J. Evers
- Emory Institute for Drug Discovery (EIDD), 1515 Dickey Drive, Atlanta, Georgia
30322, United States
| | - Randy B. Howard
- Emory Institute for Drug Discovery (EIDD), 1515 Dickey Drive, Atlanta, Georgia
30322, United States
| | - Deborah G. Culver
- Emory Institute for Drug Discovery (EIDD), 1515 Dickey Drive, Atlanta, Georgia
30322, United States
| | - Dennis C. Liotta
- Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia
30322, United States
- Emory Institute for Drug Discovery (EIDD), 1515 Dickey Drive, Atlanta, Georgia
30322, United States
| | - Mary R. Galinski
- Emory Vaccine Center and Yerkes
National Primate Research Center, Emory University, Atlanta, Georgia 30329, United States
- Emory
University School of Medicine,
Department of Medicine, Division of Infectious Diseases, Emory University, Atlanta, Georgia 30322, United States
| | - Michael G. Natchus
- Emory Institute for Drug Discovery (EIDD), 1515 Dickey Drive, Atlanta, Georgia
30322, United States
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Essaka DC, White J, Rathod P, Whitmore CD, Hindsgaul O, Palcic MM, Dovichi NJ. Monitoring the uptake of glycosphingolipids in Plasmodium falciparum-infected erythrocytes using both fluorescence microscopy and capillary electrophoresis with laser-induced fluorescence detection. Anal Chem 2010; 82:9955-8. [PMID: 21043509 DOI: 10.1021/ac1021776] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The metabolism of glycosphingolipids by the malaria-causing parasite Plasmodium falciparum plays an important role in the progression of the disease. We report a new and highly sensitive method to monitor the uptake of glycosphingolipids in infected red blood cells (iRBCs). A tetramethylrhodamine-labeled glycosphingolipid (GM1-TMR) was used as a substrate. Uptake was demonstrated by fluorescence microscopy. The iRBCs were lysed with a 15% solution of saponin and washed with phosphate buffered saline to release intact parasites. The parasites were further lysed and the resulting homogenates were analyzed by capillary electrophoresis with laser-induced fluorescence detection. The lysate from erythrocytes infected at 1% parasitemia generated a signal 20 standard deviations larger than uninfected erythrocytes, which suggests that relatively low infection levels can be studied with this technique.
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Affiliation(s)
- David C Essaka
- Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195, USA
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17
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Azouzi S, El Kirat K, Morandat S. The potent antimalarial drug cyclosporin A preferentially destabilizes sphingomyelin-rich membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:1960-1965. [PMID: 19697916 DOI: 10.1021/la902580w] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Cyclosporin A (CsA) is a hydrophobic cyclic peptide produced by a fungus. CsA is widely used as an immunosuppressive agent to inhibit the rejection of transplanted organs. CsA also exhibits an antiparasitic activity against Plasmodium, the microorganism responsible for malaria disease. This antimalarial activity is not completely understood yet. In this study, we have used Langmuir monolayers and atomic force microscopy to investigate the interaction of CsA with different lipids: phosphatidylcholines with different molecular packing, cholesterol, and sphingomyelin. We have shown that CsA inserts in all kinds of lipid monolayers but it has a marked preference for sphingomyelin monolayers. This preferential insertion of CsA within sphingomyelin-enriched membranes could explain the antimalarial activity of CsA. Indeed, the parasites need to produce a membrane network inside the erythrocytes, which allows for their proper development/multiplication by exchanging nutrients with the external medium. This membrane network is particularly enriched in sphingomyelin, so the preferential insertion of CsA in these bilayers may destabilize them, thereby inhibiting the development of the parasite.
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Affiliation(s)
- Slim Azouzi
- Laboratoire de Génie Enzymatique et Cellulaire, CNRS UMR 6022, 60205 Compiègne Cedex, France
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18
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Zhang K, Bangs JD, Beverley SM. Sphingolipids in Parasitic Protozoa. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 688:238-48. [DOI: 10.1007/978-1-4419-6741-1_17] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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19
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Tamez PA, Bhattacharjee S, van Ooij C, Hiller NL, Llinás M, Balu B, Adams JH, Haldar K. An erythrocyte vesicle protein exported by the malaria parasite promotes tubovesicular lipid import from the host cell surface. PLoS Pathog 2008; 4:e1000118. [PMID: 18688278 PMCID: PMC2483944 DOI: 10.1371/journal.ppat.1000118] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2007] [Accepted: 07/10/2008] [Indexed: 11/18/2022] Open
Abstract
Plasmodium falciparum is the protozoan parasite that causes the most virulent of human malarias. The blood stage parasites export several hundred proteins into their host erythrocyte that underlie modifications linked to major pathologies of the disease and parasite survival in the blood. Unfortunately, most are ‘hypothetical’ proteins of unknown function, and those that are essential for parasitization of the erythrocyte cannot be ‘knocked out’. Here, we combined bioinformatics and genome-wide expression analyses with a new series of transgenic and cellular assays to show for the first time in malaria parasites that microarray read out from a chemical perturbation can have predictive value. We thereby identified and characterized an exported P. falciparum protein resident in a new vesicular compartment induced by the parasite in the erythrocyte. This protein, named Erythrocyte Vesicle Protein 1 (EVP1), shows novel dynamics of distribution in the parasite and intraerythrocytic membranes. Evidence is presented that its expression results in a change in TVN-mediated lipid import at the host membrane and that it is required for intracellular parasite growth, but not invasion. This exported protein appears to be needed for the maintenance of an essential tubovesicular nutrient import pathway induced by the pathogen in the host cell. Our approach may be generalized to the analysis of hundreds of ‘hypothetical’ P. falciparum proteins to understand their role in parasite entry and/or growth in erythrocytes as well as phenotypic contributions to either antigen export or tubovesicular import. By functionally validating these unknowns, one may identify new targets in host–microbial interactions for prophylaxis against this major human pathogen. Plasmodium falciparum, the most virulent form of human malaria, causes disease when it invades a red blood cell. It sends proteins beyond its borders into the host, changing the red cell to make it a suitable environment to live in and to interact with the host immune system. Recent findings have predicted that hundreds of parasite proteins are released into the host red cell. However, most of these proteins have no known function. One major challenge is to understand what role these proteins play in parasite growth in order to design drugs or vaccines that block protein function. In this study, we designed a strategy to characterize ‘hypothetical’ proteins and use one as an example to illustrate the principle. We show that this protein resides within a novel compartment within the red cell and changes lipid transport at the host surface to stabilize a major nutrient pathway formed within the human cell. In principle, this strategy is applicable in determining the functions of other parasite genes involved in pathogen–host interactions.
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Affiliation(s)
- Pamela A. Tamez
- Department of Pathology, Feinberg School of Medicine, Northwestern University Chicago, Illinois, United States of America
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University Chicago, Illinois, United States of America
| | - Souvik Bhattacharjee
- Department of Pathology, Feinberg School of Medicine, Northwestern University Chicago, Illinois, United States of America
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University Chicago, Illinois, United States of America
| | - Christiaan van Ooij
- Department of Pathology, Feinberg School of Medicine, Northwestern University Chicago, Illinois, United States of America
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University Chicago, Illinois, United States of America
| | - N. Luisa Hiller
- Allegheny General Hospital, Allegheny-Singer Research Institute, Center for Genomic Sciences, Pittsburgh, Pennsylvania, United States of America
| | - Manuel Llinás
- Department of Molecular Biology, Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - Bharath Balu
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - John H. Adams
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Kasturi Haldar
- Department of Pathology, Feinberg School of Medicine, Northwestern University Chicago, Illinois, United States of America
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University Chicago, Illinois, United States of America
- * E-mail:
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20
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The malaria secretome: from algorithms to essential function in blood stage infection. PLoS Pathog 2008; 4:e1000084. [PMID: 18551176 PMCID: PMC2408878 DOI: 10.1371/journal.ppat.1000084] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Accepted: 05/07/2008] [Indexed: 01/15/2023] Open
Abstract
The malaria agent Plasmodium falciparum is predicted to export a “secretome” of several hundred proteins to remodel the host erythrocyte. Prediction of protein export is based on the presence of an ER-type signal sequence and a downstream Host-Targeting (HT) motif (which is similar to, but distinct from, the closely related Plasmodium Export Element [PEXEL]). Previous attempts to determine the entire secretome, using either the HT-motif or the PEXEL, have yielded large sets of proteins, which have not been comprehensively tested. We present here an expanded secretome that is optimized for both P. falciparum signal sequences and the HT-motif. From the most conservative of these three secretome predictions, we identify 11 proteins that are preserved across human- and rodent-infecting Plasmodium species. The conservation of these proteins likely indicates that they perform important functions in the interaction with and remodeling of the host erythrocyte important for all Plasmodium parasites. Using the piggyBac transposition system, we validate their export and find a positive prediction rate of ∼70%. Even for proteins identified by all secretomes, the positive prediction rate is not likely to exceed ∼75%. Attempted deletions of the genes encoding the conserved exported proteins were not successful, but additional functional analyses revealed the first conserved secretome function. This gave new insight into mechanisms for the assembly of the parasite-induced tubovesicular network needed for import of nutrients into the infected erythrocyte. Thus, genomic screens combined with functional assays provide unexpected and fundamental insights into host remodeling by this major human pathogen. The parasite Plasmodium falciparum causes malaria by replicating inside red blood cells of infected individuals. By exporting many different proteins into the host cell, the parasite changes many of its properties. Knowledge of the identity and function of all the exported proteins will both increase our understanding of the modifications required for parasite survival and provide us with targets that can be inhibited to block the growth of the parasites. Several years ago, a motif within the exported proteins was discovered that allowed them to be exported, which was used to predict the total set of proteins exported to the host cell (the secretome). We show here that the earlier studies have either under- or overestimated the total number of proteins exported into the host cell, and derive a more accurate prediction of proteins exported to the host cell. We validate the predictions by making parasites that express a fusion of predicted exported proteins to the Green Fluorescent Protein (which allows the localization of the protein to be determined visually). This revealed a positive prediction rate of ∼70%. In addition, several proteins were identified that are very likely to play an essential role in infection, with at least one involved in the formation of a structure required for nutrient import.
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21
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Rebollo O, del Olmo E, Ruiz G, López-Pérez JL, Giménez A, San Feliciano A. Leishmanicidal and trypanocidal activities of 2-aminocyclohexanol and 1,2-cyclohexanediamine derivatives. Bioorg Med Chem Lett 2008; 18:184-7. [DOI: 10.1016/j.bmcl.2007.10.102] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2007] [Revised: 10/26/2007] [Accepted: 10/27/2007] [Indexed: 11/17/2022]
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22
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A sphingolipid inhibitor induces a cytokinesis arrest and blocks stage differentiation in Giardia lamblia. Antimicrob Agents Chemother 2007; 52:563-9. [PMID: 18086854 DOI: 10.1128/aac.01105-07] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sphingolipid biosynthesis pathways have recently emerged as a promising target for therapeutic intervention against pathogens, including parasites. A key step in the synthesis of complex sphingolipids is the glucosylation of ceramide, mediated by glucosylceramide (GlcCer) synthase, whose activity can be inhibited by PPMP (1-phenyl-2-palmitoylamino-3-morpholino-1-propanol). In this study, we investigated whether PPMP inhibits the proliferation and differentiation of the pathogenic parasite Giardia lamblia, the major cause of parasite-induced diarrhea worldwide. PPMP was found to block in vitro parasite replication in a dose-dependent manner, with a 50% inhibitory concentration of 3.5 muM. The inhibition of parasite replication was irreversible at 10 muM PPMP, a concentration that did not affect mammalian cell metabolism. Importantly, PPMP inhibited the completion of cell division at a specific stage in late cytokinesis. Microscopic analysis of cells incubated with PPMP revealed the aberrant accumulation of cellular membranes belonging to the endoplasmic reticulum network in the caudal area of the parasites. Finally, PPMP induced a 90% reduction in G. lamblia differentiation into cysts, the parasite stage responsible for the transmission of the disease. These results show that PPMP is a powerful inhibitor of G. lamblia in vitro and that as-yet-uncharacterized sphingolipid biosynthetic pathways are potential targets for the development of anti-G. lamblia agents.
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23
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Debierre-Grockiego F, Schofield L, Azzouz N, Schmidt J, Santos de Macedo C, Ferguson MAJ, Schwarz RT. Fatty acids from Plasmodium falciparum down-regulate the toxic activity of malaria glycosylphosphatidylinositols. Infect Immun 2006; 74:5487-96. [PMID: 16988223 PMCID: PMC1594897 DOI: 10.1128/iai.01934-05] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Plasmodium falciparum malaria kills roughly 2.5 million people, mainly children, annually. Much of this mortality is thought to arise from the actions of a malarial toxin. This toxin, identified as glycosylphosphatidylinositol (GPI), is a major pathogenicity determinant in malaria. A malarial molecule, Pfj, labeled by [3H]glucosamine like the GPIs, was identified as a non-GPI molecule. Here we show that Pfj is able to down-regulate tumor necrosis factor alpha (TNF-alpha) production induced by the GPI of P. falciparum. Mass spectrometry analysis showed that Pfj was not a single molecule but represented a number of molecules. Separation methods, such as cation-exchange chromatography and thin-layer chromatography, were used to isolate and identify the following four main fatty acids responsible for the inhibitory effect on TNF-alpha production: myristic, pentadecanoic, palmitic, and palmitoleic acids. This regulatory effect on cytokine production suggests that there is balanced bioactivity for the different categories of malarial lipids.
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Abstract
Every year, forty percent of the world population is at risk of contracting malaria. Hopes for the erradication of this disease during the 20th century were dashed by the ability of Plasmodium falciparum, its most deadly causative agent, to develop resistance to available drugs. Efforts to produce an effective vaccine have so far been unsuccessful, enhancing the need to develop novel antimalarial drugs. In this review, we summarize our knowledge concerning existing antimalarials, mechanisms of drug-resistance development, the use of drug combination strategies and the quest for novel anti-plasmodial compounds. We emphasize the potential role of host genes and molecules as novel targets for newly developed drugs. Recent results from our laboratory have shown Hepatocyte Growth Factor/MET signaling to be essential for the establishment of infection in hepatocytes. We discuss the potential use of this pathway in the prophylaxis of malaria infection.
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25
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Affiliation(s)
- Lena J Heung
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, 173 Ashley Ave., BSB 503, Charleston, SC 29425, USA
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26
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Mercier C, Adjogble KDZ, Däubener W, Delauw MFC. Dense granules: are they key organelles to help understand the parasitophorous vacuole of all apicomplexa parasites? Int J Parasitol 2006; 35:829-49. [PMID: 15978597 DOI: 10.1016/j.ijpara.2005.03.011] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2004] [Revised: 03/07/2005] [Accepted: 03/18/2005] [Indexed: 02/06/2023]
Abstract
Together with micronemes and rhoptries, dense granules are specialised secretory organelles of Apicomplexa parasites. Among Apicomplexa, Plasmodium represents a model of parasites propagated by way of an insect vector, whereas Toxoplasma is a model of food borne protozoa forming cysts. Through comparison of both models, this review summarises data accumulated over recent years on alternative strategies chosen by these parasites to develop within a parasitophorous vacuole and explores the role of dense granules in this process. One of the characteristics of the Plasmodium erythrocyte stages is to export numerous parasite proteins into both the host cell cytoplasm and/or plasma membrane via the vacuole used as a step trafficking compartment. Whether this feature can be correlated to few storage granules and a restricted number of dense granule proteins, is not yet clear. By contrast, the Toxoplasma developing vacuole is decorated by abundantly expressed dense granule proteins and is characterised by a network of membranous nanotubes. Although the exact function of most of these proteins remains currently unknown, recent data suggest that some of these dense granule proteins could be involved in building the intravacuolar membranous network. Conserved expression of the Toxoplasma dense granule proteins throughout most of the parasite stages suggests that they could also be key elements of the cyst formation.
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Affiliation(s)
- Corinne Mercier
- Institut Jean Roget, Université Joseph Fourier, CNRS UMR 5163, Place du Commandant Nal., 38700 La Tronche, France.
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27
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Radin NS. Preventing the binding of pathogens to the host by controlling sphingolipid metabolism. Microbes Infect 2006; 8:938-45. [PMID: 16460984 DOI: 10.1016/j.micinf.2005.09.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2005] [Revised: 09/05/2005] [Accepted: 09/06/2005] [Indexed: 11/16/2022]
Abstract
The binding of many pathogens and toxins to human cells can be inhibited by (1) depleting host cells of their surface glycosphingolipids; (2) coating the binding sites on pathogens (adhesins) with glycosphingolipid-like substances (decoys); (3) coating the host's glycosphingolipids with substances that compete with the pathogen for binding. Details of using these methods are described.
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Affiliation(s)
- Norman S Radin
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI, USA.
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28
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Sonda S, Hehl AB. Lipid biology of Apicomplexa: perspectives for new drug targets, particularly for Toxoplasma gondii. Trends Parasitol 2005; 22:41-7. [PMID: 16300997 DOI: 10.1016/j.pt.2005.11.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2005] [Revised: 09/20/2005] [Accepted: 11/07/2005] [Indexed: 11/19/2022]
Abstract
Development of effective therapies for intracellular eukaryotic pathogens is a serious challenge, given the protected location of these pathogens and the similarity of their biology to that of the host. Identifying cellular processes that are unique to the parasite is therefore a crucial step towards defining appropriate drug targets. In the case of the apicomplexan parasite Toxoplasma gondii, the need to find alternative treatments is imperative because of the poor tolerability and frequent side-effects associated with existing therapeutic strategies. The discovery that the parasite uses lipid synthetic pathways which are different from, or absent in, the mammalian host is now driving a renewed interest in T. gondii lipid biology. Recent achievements in this field are promising and suggest that the elucidation of lipid pathways will provide new opportunities for designing potent antiparasitic strategies.
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Affiliation(s)
- Sabrina Sonda
- Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, CH-8057 Zurich, Switzerland.
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Labaied M, Dagan A, Dellinger M, Gèze M, Egée S, Thomas SL, Wang C, Gatt S, Grellier P. Anti-Plasmodium activity of ceramide analogs. Malar J 2004; 3:49. [PMID: 15588325 PMCID: PMC539285 DOI: 10.1186/1475-2875-3-49] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2004] [Accepted: 12/10/2004] [Indexed: 11/10/2022] Open
Abstract
Background Sphingolipids are key molecules regulating many essential functions in eukaryotic cells and ceramide plays a central role in sphingolipid metabolism. A sphingolipid metabolism occurs in the intraerythrocytic stages of Plasmodium falciparum and is associated with essential biological processes. It constitutes an attractive and potential target for the development of new antimalarial drugs. Methods The anti-Plasmodium activity of a series of ceramide analogs containing different linkages (amide, methylene or thiourea linkages) between the fatty acid part of ceramide and the sphingoid core was investigated in culture and compared to the sphingolipid analog PPMP (d,1-threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol). This analog is known to inhibit the parasite sphingomyelin synthase activity and block parasite development by preventing the formation of the tubovesicular network that extends from the parasitophorous vacuole to the red cell membrane and delivers essential extracellular nutrients to the parasite. Results Analogs containing methylene linkage showed a considerably higher anti-Plasmodium activity (IC50 in the low nanomolar range) than PPMP and their counterparts with a natural amide linkage (IC50 in the micromolar range). The methylene analogs blocked irreversibly P. falciparum development leading to parasite eradication in contrast to PPMP whose effect is cytostatic. A high sensitivity of action towards the parasite was observed when compared to their effect on the human MRC-5 cell growth. The toxicity towards parasites did not correlate with the inhibition by methylene analogs of the parasite sphingomyelin synthase activity and the tubovesicular network formation, indicating that this enzyme is not their primary target. Conclusions It has been shown that ceramide analogs were potent inhibitors of P. falciparum growth in culture. Interestingly, the nature of the linkage between the fatty acid part and the sphingoid core considerably influences the antiplasmodial activity and the selectivity of analogs when compared to their cytotoxicity on mammalian cells. By comparison with their inhibitory effect on cancer cell growth, the ceramide analogs might inhibit P. falciparum growth through modulation of the endogenous ceramide level.
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Affiliation(s)
- Mehdi Labaied
- USM0504 Biologie fonctionnelle des protozoaires, Département Régulations, Développement, Diversité Moléculaire, Muséum National d'Histoire Naturelle, Boite postale n°52, 61 rue Buffon, 75231 Paris Cedex 05, France
| | - Arie Dagan
- Department of Biochemistry, Hebrew University-Hadassah School of Medicine, P.O. Box 12272, Jerusalem, 91120, Israel
| | - Marc Dellinger
- USM0504 Biologie fonctionnelle des protozoaires, Département Régulations, Développement, Diversité Moléculaire, Muséum National d'Histoire Naturelle, Boite postale n°52, 61 rue Buffon, 75231 Paris Cedex 05, France
| | - Marc Gèze
- USM0504 Biologie fonctionnelle des protozoaires, Département Régulations, Développement, Diversité Moléculaire, Muséum National d'Histoire Naturelle, Boite postale n°52, 61 rue Buffon, 75231 Paris Cedex 05, France
| | - Stéphane Egée
- CNRS FRE 2775, Station biologique de Roscoff, 29682 Roscoff, France
| | - Serge L Thomas
- CNRS FRE 2775, Station biologique de Roscoff, 29682 Roscoff, France
| | - Chunbo Wang
- Department of Biochemistry, Hebrew University-Hadassah School of Medicine, P.O. Box 12272, Jerusalem, 91120, Israel
| | - Shimon Gatt
- Department of Biochemistry, Hebrew University-Hadassah School of Medicine, P.O. Box 12272, Jerusalem, 91120, Israel
| | - Philippe Grellier
- USM0504 Biologie fonctionnelle des protozoaires, Département Régulations, Développement, Diversité Moléculaire, Muséum National d'Histoire Naturelle, Boite postale n°52, 61 rue Buffon, 75231 Paris Cedex 05, France
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30
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Nawabi P, Lykidis A, Ji D, Haldar K. Neutral-lipid analysis reveals elevation of acylglycerols and lack of cholesterol esters in Plasmodium falciparum-infected erythrocytes. EUKARYOTIC CELL 2004; 2:1128-31. [PMID: 14555495 PMCID: PMC219371 DOI: 10.1128/ec.2.5.1128-1131.2003] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Here we show that blood-stage Plasmodium falciparum organisms accumulate a high mass of triacylglycerol and diacylglycerol. However, we failed to detect cholesterol esters, a second neutral lipid species reported to be important for a related apicomplexan, Toxoplasma gondii. Evidence for P. falciparum and T. gondii homologues of acyl coenzyme A:diacylglycerol acyltransferase suggests that acylglycerols may be the conserved neutral lipids in apicomplexans.
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Affiliation(s)
- Parwez Nawabi
- Departments of Pathology and Microbiology-Immunology, Northwestern University Medical School, Chicago, Illinois 60611, USA
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31
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Couto AS, Caffaro C, Uhrig ML, Kimura E, Peres VJ, Merino EF, Katzin AM, Nishioka M, Nonami H, Erra-Balsells R. Glycosphingolipids in Plasmodium falciparum. Presence of an active glucosylceramide synthase. ACTA ACUST UNITED AC 2004; 271:2204-14. [PMID: 15153110 DOI: 10.1111/j.1432-1033.2004.04150.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Malaria remains a major health problem especially in tropical and subtropical regions of the world, and therefore developing new antimalarial drugs constitutes an urgent challenge. Lipid metabolism has been attracting a lot of attention as an application for malarial chemotherapeutic purposes in recent years. However, little is known about glycosphingolipid biosynthesis in Plasmodium falciparum. In this report we describe for the first time the presence of an active glucosylceramide synthase in the intraerythrocytic stages of the parasite. Two different experiments, using UDP-[(14)C]glucose as donor with ceramides as acceptors, or UDP-glucose as donor and fluorescent ceramides as acceptors, were performed. In both cases, we found that the parasitic enzyme was able to glycosylate only dihydroceramide. The enzyme activity could be inhibited in vitro with low concentrations of d,l-threo-phenyl-2-palmitoylamino-3-morpholino-1-propanol (PPMP). In addition, de novo biosynthesis of glycosphingolipids was shown by metabolic incorporation of [(14)C]palmitic acid and [(14)C]glucose in the three intraerythrocytic stages of the parasite. The structure of the ceramide, monohexosylceramide, trihexosylceramide and tetrahexosylceramide fractions was analysed by UV-MALDI-TOF mass spectrometry. When PPMP was added to parasite cultures, a correlation between arrest of parasite growth and inhibition of glycosphingolipid biosynthesis was observed. The particular substrate specificity of the malarial glucosylceramide synthase must be added to the already known unique and amazing features of P. falciparum lipid metabolism; therefore this enzyme might represent a new attractive target for malarial chemotherapy.
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Affiliation(s)
- Alicia S Couto
- CIHIDECAR, Departamento de Química Orgánica, Pabellón II, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina.
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32
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Lang F, Lang PA, Lang KS, Brand V, Tanneur V, Duranton C, Wieder T, Huber SM. Channel-induced apoptosis of infected host cells-the case of malaria. Pflugers Arch 2004; 448:319-24. [PMID: 15042371 DOI: 10.1007/s00424-004-1254-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2004] [Revised: 02/13/2004] [Accepted: 02/17/2004] [Indexed: 12/16/2022]
Abstract
Infection of erythrocytes by the malaria pathogen Plasmodium falciparum leads to activation of several distinct anion channels and a non-selective, Ca2+-permeable cation channel. All channel types are presumably activated by the oxidative stress generated by the pathogen. Similar or identical channels are activated by oxidation of non-infected erythrocytes. Activation of the non-selective cation channel allows entry of Ca2+ and Na+, both of which are required for intracellular growth of the pathogen. The entry of Ca2+ stimulates an intraerythrocytic scramblase that facilitates bi-directional phospholipid migration across the bilayer, resulting in breakdown of the phosphatidylserine asymmetry of the cell membrane. The exposure of phosphatidylserine at the outer surface of the cell membrane is presumably followed by binding to phosphatidylserine receptors on macrophages and subsequent phagocytosis of the affected erythrocyte. The lysosomal degradation may eventually eliminate the pathogen. The channel may thus play a dual role in pathogen survival. Absence of the channels is not compatible with pathogen growth, enhanced channel activity accelerates erythrocyte "apoptosis" that may represent a host defence mechanism serving to eliminate infected erythrocytes.
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Affiliation(s)
- Florian Lang
- Physiologisches Institut der Universität Tübingen, Gmelinstrasse 5, 72076 Tübingen, Germany.
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33
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Chattopadhyay A, Kalipatnapu S. Serotonin1A receptor agonist acquires an antimalarial connection. J Biosci 2004; 29:1-2. [PMID: 15295204 DOI: 10.1007/bf02702554] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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34
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A novel synthesis of substituted quinolines using ring-closing metathesis (RCM): its application to the synthesis of key intermediates for anti-malarial agents. Tetrahedron 2004. [DOI: 10.1016/j.tet.2004.01.084] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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35
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Huitema K, van den Dikkenberg J, Brouwers JFHM, Holthuis JCM. Identification of a family of animal sphingomyelin synthases. EMBO J 2003; 23:33-44. [PMID: 14685263 PMCID: PMC1271672 DOI: 10.1038/sj.emboj.7600034] [Citation(s) in RCA: 621] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2003] [Accepted: 11/20/2003] [Indexed: 11/09/2022] Open
Abstract
Sphingomyelin (SM) is a major component of animal plasma membranes. Its production involves the transfer of phosphocholine from phosphatidylcholine onto ceramide, yielding diacylglycerol as a side product. This reaction is catalysed by SM synthase, an enzyme whose biological potential can be judged from the roles of diacylglycerol and ceramide as anti- and proapoptotic stimuli, respectively. SM synthesis occurs in the lumen of the Golgi as well as on the cell surface. As no gene for SM synthase has been cloned so far, it is unclear whether different enzymes are present at these locations. Using a functional cloning strategy in yeast, we identified a novel family of integral membrane proteins exhibiting all enzymatic features previously attributed to animal SM synthase. Strikingly, human, mouse and Caenorhabditis elegans genomes each contain at least two different SM synthase (SMS) genes. Whereas human SMS1 is localised to the Golgi, SMS2 resides primarily at the plasma membrane. Collectively, these findings open up important new avenues for studying sphingolipid function in animals.
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Affiliation(s)
- Klazien Huitema
- Department of Membrane Enzymology, Faculty of Chemistry, Institute of Biomembranes, Utrecht University, Utrecht, The Netherlands
| | - Joep van den Dikkenberg
- Department of Membrane Enzymology, Faculty of Chemistry, Institute of Biomembranes, Utrecht University, Utrecht, The Netherlands
| | - Jos F H M Brouwers
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Joost C M Holthuis
- Department of Membrane Enzymology, Faculty of Chemistry, Institute of Biomembranes, Utrecht University, Utrecht, The Netherlands
- Department of Membrane Enzymology, Faculty of Chemistry, University of Utrecht, Padualaan 8, 3584 CH Utrecht, The Netherlands. Tel.: +31 30 253 6630; Fax: +31 30 252 2478; E-mail:
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36
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Mitamura T, Palacpac NMQ. Lipid metabolism in Plasmodium falciparum-infected erythrocytes: possible new targets for malaria chemotherapy. Microbes Infect 2003; 5:545-52. [PMID: 12758284 DOI: 10.1016/s1286-4579(03)00070-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The emergence and spread of drug-resistant parasites coupled with the absence of an effective vaccine makes malaria treatment more complicated, and thus the development of new antimalarial drugs is one of the urgent tasks in malaria research. This review highlights lipid metabolism in Plasmodium parasite cells, the study of which would lead to providing new targets for therapeutic intervention.
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Affiliation(s)
- Toshihide Mitamura
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
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37
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Hoessli DC, Poincelet M, Gupta R, Ilangumaran S. Plasmodium falciparum merozoite surface protein 1. EUROPEAN JOURNAL OF BIOCHEMISTRY 2003; 270:366-75. [PMID: 12605687 DOI: 10.1046/j.1432-1033.2003.03397.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In addition to the major carbohydrate moieties of the glycosylphosphatidylinositol (GPI) anchor, we report that Plasmodium falciparum merozoite surface protein 1 (MSP-1) bears O-GlcNAc modifications predominantly in beta-anomeric configuration, in both the C- and N-terminal portions of the protein. Subcellular fractionation of parasitized erythrocytes in the late trophozoite/schizont stage reveals that GPI-anchored C-terminal fragments of MSP-1 are recovered in Triton X-100 resistant, low-density membrane fractions. Our results suggest that O-GlcNAc-modified MSP-1 N-terminal fragments tend to localize within the parasitophorous vacuolar membrane while GPI-anchored MSP-1 C-terminal fragments associate with low-density, Triton X-100 resistant membrane domains (rafts), redistribute in the parasitized erythrocyte and are eventually shed as membrane vesicles that also contain the endogenous, GPI-linked CD59.
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Affiliation(s)
- Daniel C Hoessli
- Department of Pathology, Centre médical universitaire, Geneva, Switzerland.
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38
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Haldar K, Mohandas N, Samuel BU, Harrison T, Hiller NL, Akompong T, Cheresh P. Protein and lipid trafficking induced in erythrocytes infected by malaria parasites. Cell Microbiol 2002; 4:383-95. [PMID: 12102685 DOI: 10.1046/j.1462-5822.2002.00204.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The human malaria parasite Plasmodium falciparum develops in a parasitophorous vacuolar membrane (PVM) within the mature red cell and extensively modifies structural and antigenic properties of this host cell. Recent studies shed significant new, mechanistic perspective on the underlying processes. There is finally, definitive evidence that despite the absence of endocytosis, transmembrane proteins in the host red cell membrane are imported in to the PVM. These are not major erythrocyte proteins but components that reside in detergent resistant membrane (DRM) rafts in red cell membrane and are detected in rafts in the PVM. Disruption of either erythrocyte or vacuolar rafts is detrimental to infection suggesting that raft proteins and lipids are essential for the parasitization of the red cell. On secretory export of parasite proteins: an ER secretory signal (SS) sequence is required for protein secretion to the PV. Proteins carrying an additional plastid targeting sequence (PTS) are also detected in the PV but subsequently delivered to the plastid organelle within the parasite, suggesting that the PTS may have a second function as an endocytic sorting signal. A distinct but yet undefined peptidic motif underlies protein transport across the PVM to the red cell (although all of the published data does not yet fit this model). Further multiple exported proteins transit through secretory 'cleft' structures, suggesting that clefts may be sorting compartments assembled by the parasite in the red cell.
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Affiliation(s)
- Kasturi Haldar
- Department of Pathology, Northwestern University, 303 E. Chicago Avenue, Chicago, IL 60611, USA.
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39
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Azzouz N, Rauscher B, Gerold P, Cesbron-Delauw MF, Dubremetz JF, Schwarz RT. Evidence for de novo sphingolipid biosynthesis in Toxoplasma gondii. Int J Parasitol 2002; 32:677-84. [PMID: 12062486 DOI: 10.1016/s0020-7519(02)00009-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Glycolipids are important components of cellular membranes involved in various biological functions. In this report, we describe the identification of the de novo synthesis of glycosphingolipids by Toxoplasma gondii tachyzoites. Parasite-specific glycolipids were identified by metabolic labelling of parasites with tritiated serine and galactose. These glycolipids were characterised as sphingolipids based on the labelling protocol and their insensitivity towards alkaline treatment. Synthesis of parasite glycosphingolipids were inhibited by threo-phenyl-2-palmitoylamino-3-morpholino-1-propanol and L-cycloserine, two well-established inhibitors of de novo sphingolipid biosynthesis. The identified glycolipids were insensitive towards treatment with endoglycoceramidase II indicating that they might belong to globo-type glycosphingolipids. Taken together, we provide evidence for the first time that T. gondii is capable of synthesising glycosphingolipids de novo.
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Affiliation(s)
- Nahid Azzouz
- Medizinisches Zentrum für Hygiene und Medizinische Mikrobiologie, Philipps-Universität Marburg, Robert-Koch Strasse 17, 35037, Marburg, Germany
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40
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Cheresh P, Harrison T, Fujioka H, Haldar K. Targeting the malarial plastid via the parasitophorous vacuole. J Biol Chem 2002; 277:16265-77. [PMID: 11815606 DOI: 10.1074/jbc.m109331200] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The malarial "apicoplast" derived from an algal plastid, has stimulated interest for its novel evolutionary biology and potential as a drug target. An endoplasmic reticulum-type signal sequence followed by a plastid targeting sequence are required to target proteins to the apicoplast but the pathway by which proteins are transported to the organelle is unknown. By stage regulating the expression of transgenes we show that early (0-12 h) in the parasite's development in red cells, newly synthesized green fluorescent protein that contains the plastid targeting sequence (plastid targeting sequence-green fluorescent protein (PTS-GFP)) is recruited into the parasite's secretory pathway. PTS-GFP in 0-12-h parasites is found released into the parasitophorous vacuole (PV) and in apposition with the Golgi. However, import into the apicoplast and processing to GFP does not occur until 18-36 h in development. In intermediate, 18-h parasites PTS-GFP resides in the PV. Quantitative exit of PTS-GFP from the PV and its conversion to GFP is seen at 36 h. The data suggest that: (i) import into the apicoplast is stage regulated and (ii) the PTS can signal endomembrane targeting from the PV to the apicoplast.
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Affiliation(s)
- Paul Cheresh
- Department Pathology, Northwestern University, Chicago, Illinois 60611, USA
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41
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Hanada K, Palacpac NMQ, Magistrado PA, Kurokawa K, Rai G, Sakata D, Hara T, Horii T, Nishijima M, Mitamura T. Plasmodium falciparum phospholipase C hydrolyzing sphingomyelin and lysocholinephospholipids is a possible target for malaria chemotherapy. J Exp Med 2002; 195:23-34. [PMID: 11781362 PMCID: PMC2196011 DOI: 10.1084/jem.20010724] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Sphingomyelinase (SMase) is one of the principal enzymes in sphingomyelin (SM) metabolism. Here, we identified a Plasmodium falciparum gene (PfNSM) encoding a 46-kD protein, the amino acid sequence of which is approximately 25% identical to that of bacteria SMases. Biochemical analyses of the recombinant protein GST-PfNSM, a fusion protein of the PfNSM product with glutathione-S-transferase, reveal that this enzyme retained similar characteristics in various aspects to SMase detected in P. falciparum-infected erythrocytes and isolated parasites. In addition, the recombinant protein retains hydrolyzing activity not only of SM but also of lysocholinephospholipids (LCPL) including lysophosphatidylcholine and lysoplatelet-activating factor, indicating that PfNSM encodes SM/LCPL-phospholipase C (PLC). Scyphostatin inhibited SM/LCPL-PLC activities of the PfNSM product as well as the intraerythrocytic proliferation of P. falciparum in a dose-dependent manner with ID(50) values for SM/LCPL-PLC activities and the parasite growth at 3-5 microM and approximately 7 microM, respectively. Morphological analysis demonstrated most severe impairment in the intraerythrocytic development with the addition of scyphostatin at trophozoite stage than at ring or schizont stages, suggesting its effect specifically on the stage progression from trophozoite to schizont, coinciding with the active transcription of PfNSM gene.
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Affiliation(s)
- Kentaro Hanada
- Department of Biochemistry and Cell Biology, Japan Science and Technology Corporation, National Institute of Infectious Diseases, 1-23-1, Toyama, Shinjuku-ku, Tokyo 162-8640, Japan.
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42
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Haldar K, Samuel BU, Mohandas N, Harrison T, Hiller NL. Transport mechanisms in Plasmodium-infected erythrocytes: lipid rafts and a tubovesicular network. Int J Parasitol 2001; 31:1393-401. [PMID: 11566306 DOI: 10.1016/s0020-7519(01)00251-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The mature human erythrocyte is a simple cell that is devoid of intracellular organelles and does not show endocytic or phagocytic activity at the plasma membrane. However, following infection by Plasmodium, the erythrocyte undergoes several morphological and functional changes. Parasite-derived proteins are exported into the erythrocyte cytoplasm and to the membrane, while several proteins are localised to the parasitophorous vacuolar membrane and to the tubovesicular membranous network structures surrounding the parasite. Recent evidence indicates that multiple host proteins, independent of the type of their membrane anchor, that exist in detergent-resistant membrane (DRM) rafts or microdomains enter this apicomplexan vacuole. The internalised host components along with the parasite-encoded transmembrane protein PfEXP1 can be detected as DRM rafts in the vacuole. It appears that in Plasmodium-infected erythrocytes lipid rafts may play a role in endovacuolation and macromolecular transport.
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Affiliation(s)
- K Haldar
- Department of Pathology, Northwestern University, 303 East Chicago Avenue, Chicago, IL 60611, USA
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43
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Haldar K, Samuel BU, Mohandas N, Harrison T, Hiller NL. Erythrocytic vacuolar rafts induced by malaria parasites. Curr Opin Hematol 2001; 8:92-7. [PMID: 11224683 DOI: 10.1097/00062752-200103000-00006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Studies in the past year displaced long-standing dogmas and provided many new molecular insights into how proteins and solutes move between the erythrocyte plasma membrane and the malarial vacuole. Highlights include a demonstration that (1) detergent-resistant membrane (DRM) rafts exist in the red cell membrane and their resident proteins are detected as rafts in the plasmodial vacuole, (2) a voltage-gated channel in the infected red cell membrane mediates uptake of extracellular nutrient solutes, and (3) intraerythrocytic membranes transport a parasite-encoded adherence antigen to the red cell surface.
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Affiliation(s)
- K Haldar
- Departments of Pathology and Microbiology-Immunology, Northwestern University, Chicago, Illinois, USA.
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44
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Gerold P, Schwarz RT. Biosynthesis of glycosphingolipids de-novo by the human malaria parasite Plasmodium falciparum. Mol Biochem Parasitol 2001; 112:29-37. [PMID: 11166384 DOI: 10.1016/s0166-6851(00)00336-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Glycolipids are important components of cellular membranes involved in various biological functions. In this report we describe the identification of the de-novo synthesis of glycosphingolipids by intraerythrocytic, asexual stages of the malaria parasite, Plasmodium falciparum. Parasite-specific glycolipids were identified in organic solvent extracts of parasites metabolically labeled with tritiated serine and glucosamine and characterised as sphingolipids based on their insensitivity towards alkaline treatment. While the de-novo synthesis of parasite glycosphingolipids was affected by fumonisin B1, threo-PPMP, cyclo-serine and myriocin, these well established inhibitors of de-novo ceramide biosynthesis were unable to arrest the intraerythrocytic development of the parasites in culture.
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Affiliation(s)
- P Gerold
- Med. Zentrum für Hygiene und Med. Mikrobiologie, Philipps-Universität, Robert-Koch-Strasse 17, 35037 Marburg, Germany
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45
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Bannister LH, Hopkins JM, Fowler RE, Krishna S, Mitchell GH. A brief illustrated guide to the ultrastructure of Plasmodium falciparum asexual blood stages. PARASITOLOGY TODAY (PERSONAL ED.) 2000; 16:427-33. [PMID: 11006474 DOI: 10.1016/s0169-4758(00)01755-5] [Citation(s) in RCA: 219] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Interpretation of the new information arising from the Plasmodium falciparum Genome Project requires a good working knowledge of the ultrastructure of the parasite; however many aspects of the morphology of this species remain obscure. Lawrence Bannister, John Hopkins and colleagues here give an illustrated overview of the three-dimensional (3-D) organization of the merozoite, ring, trophozoite and schizont stages of the parasite, based on available data that include 3-D reconstruc-tion from serial electron microscope sections. The review describes the chief organelles present in these stages, emphasizing the continuity of structure in addition to specialized, stage-specific features developed during the asexual erythrocytic cycle.
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Affiliation(s)
- L H Bannister
- Centre for Neuroscience, Hodgkin Building, Guy's, King's and St Thomas' Hospitals School of Basic Medical Science, KCL, Guy's Campus, SE1 1UL, London, UK.
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46
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Lauer S, VanWye J, Harrison T, McManus H, Samuel BU, Hiller NL, Mohandas N, Haldar K. Vacuolar uptake of host components, and a role for cholesterol and sphingomyelin in malarial infection. EMBO J 2000; 19:3556-64. [PMID: 10899110 PMCID: PMC313993 DOI: 10.1093/emboj/19.14.3556] [Citation(s) in RCA: 172] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Erythrocytes, which are incapable of endocytosis or phagocytosis, can be infected by the malaria parasite Plasmodium falciparum. We find that a transmembrane protein (Duffy), glycosylphosphatidylinositol (GPI)-anchored and cytoplasmic proteins, associated with detergent-resistant membranes (DRMs) that are characteristic of microdomains in host cell membranes, are internalized by vacuolar parasites, while the major integral membrane and cytoskeletal proteins are not. The internalized host proteins and a plasmodial transmembrane resident parasitophorous vacuolar membrane (PVM) protein are detected in DRMs associated with vacuolar parasites. This is the first report of a host transmembrane protein being recruited into an apicomplexan vacuole and of the presence of vacuolar DRMs; it establishes that integral association does not preclude protein internalization into the P.FALCIPARUM: vacuole. Rather, as shown for Duffy, intracellular accumulation occurs at the same rate as that seen for a DRM-associated GPI-anchored protein. Furthermore, novel mechanisms regulated by the DRM lipids, sphingomyelin and cholesterol, mediate (i) the uptake of host DRM proteins and (ii) maintenance of the intracellular vacuole in the non-endocytic red cell, which may have implications for intracellular parasitism and pathogenesis.
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Affiliation(s)
- S Lauer
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
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47
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Hanada K, Mitamura T, Fukasawa M, Magistrado PA, Horii T, Nishijima M. Neutral sphingomyelinase activity dependent on Mg2+ and anionic phospholipids in the intraerythrocytic malaria parasite Plasmodium falciparum. Biochem J 2000; 346 Pt 3:671-7. [PMID: 10698693 PMCID: PMC1220899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Sphingolipid metabolism and metabolites are important in various cellular events in eukaryotes. However, little is known about their function in plasmodial parasites. Here we demonstrate that neutral sphingomyelinase (SMase) involved in the sphingomyelin (SM) catabolism is retained by the intraerythrocytic parasite Plasmodium falciparum. When assayed in a neutral pH buffer supplemented with Mg(2+) and phosphatidylserine, an activity for the release of the phosphocholine group from SM was detected in parasite-infected, but not in uninfected, erythrocyte ghosts. The SMase activity in the parasite-infected erythrocyte ghosts was enhanced markedly by anionic phospholipids including unsaturated but not saturated phosphatidylserine. Mn(2+) could not substitute for Mg(2+) to activate SMase in parasite-infected erythrocyte ghosts, whereas both Mn(2+) and Mg(2+) activated mammalian neutral SMase. The specific activity level of SMase was higher in isolated parasites than in infected erythrocyte ghosts; further fractionation of lysates of the isolated parasites showed that the activity was bound largely to the membrane fraction of the parasites. The plasmodial SMase seemed not to hydrolyse phosphatidylcholine or phosphatidylinositol. The plasmodial SMase, but not SM synthase, was sensitive to scyphostatin, an inhibitor of mammalian neutral SMase, indicating that the plasmodial activities for SM hydrolysis and SM synthesis are mediated by different catalysts. Our finding that the malaria parasites possess SMase activity might explain why the parasites seem to have an SM synthase activity but no activity to synthesize ceramide de novo.
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Affiliation(s)
- K Hanada
- Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, 1-23-1, Toyama, Shinjuku-ku, Tokyo 162-8640, Japan.
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Akompong T, VanWye J, Ghori N, Haldar K. Artemisinin and its derivatives are transported by a vacuolar-network of Plasmodium falciparum and their anti-malarial activities are additive with toxic sphingolipid analogues that block the network. Mol Biochem Parasitol 1999; 101:71-9. [PMID: 10413044 DOI: 10.1016/s0166-6851(99)00056-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
There is great need to identify and characterize drug targets and chemotherapeutic strategies against malaria. Here we show that a vacuolar-network induced by the human malaria parasite Plasmodium falciparum, is a major import pathway for artemisinin, a leading, new anti-malarial that is known to be effective against drug resistant strains. We also show that artemisinin-treatment induces aberrant, budding of a vacuolar-network membrane protein and its antimalarial activity is additive with toxic sphingolipid analogues that block the network. The data suggest that artemisinin alters membrane protein export from the vacuolar-network and combinations with anti-network reagents have the potential to provide powerful new chemotherapy for drug resistant malaria.
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Affiliation(s)
- T Akompong
- Department of Microbiology and Immunology, Stanford University School of Medicine, CA 94305-5402, USA
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Abstract
The need for new antimalarials comes from the widespread resistance to those in current use. New antimalarial targets are required to allow the discovery of chemically diverse, effective drugs. The search for such new targets and new drug chemotypes will likely be helped by the advent of functional genomics and structure-based drug design. After validation of the putative targets as those capable of providing effective and safe drugs, targets can be used as the basis for screening compounds in order to identify new leads, which, in turn, will qualify for lead optimization work. The combined use of combinatorial chemistry--to generate large numbers of structurally diverse compounds--and of high throughput screening systems--to speed up the testing of compounds--hopefully will help to optimize the process. Potential chemotherapeutic targets in the malaria parasite can be broadly classified into three categories: those involved in processes occurring in the digestive vacuole, enzymes involved in macromolecular and metabolite synthesis, and those responsible for membrane processes and signalling. The processes occurring in the digestive vacuole include haemoglobin digestion, redox processes and free radical formation, and reactions accompanying haem release followed by its polymerization into haemozoin. Many enzymes in macromolecular and metabolite synthesis are promising potential targets, some of which have been established in other microorganisms, although not yet validated for Plasmodium, with very few exceptions (such as dihydrofolate reductase). Proteins responsible for membrane processes, including trafficking and drug transport and signalling, are potentially important also to identify compounds to be used in combination with antimalarial drugs to combat resistance.
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Affiliation(s)
- P L Olliaro
- UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases, Geneva, Switzerland
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