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Pérez-Pertejo Y, García-Estrada C, Martínez-Valladares M, Murugesan S, Reguera RM, Balaña-Fouce R. Polyamine Metabolism for Drug Intervention in Trypanosomatids. Pathogens 2024; 13:79. [PMID: 38251386 PMCID: PMC10820115 DOI: 10.3390/pathogens13010079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/11/2024] [Accepted: 01/12/2024] [Indexed: 01/23/2024] Open
Abstract
Neglected tropical diseases transmitted by trypanosomatids include three major human scourges that globally affect the world's poorest people: African trypanosomiasis or sleeping sickness, American trypanosomiasis or Chagas disease and different types of leishmaniasis. Different metabolic pathways have been targeted to find antitrypanosomatid drugs, including polyamine metabolism. Since their discovery, the naturally occurring polyamines, putrescine, spermidine and spermine, have been considered important metabolites involved in cell growth. With a complex metabolism involving biosynthesis, catabolism and interconversion, the synthesis of putrescine and spermidine was targeted by thousands of compounds in an effort to produce cell growth blockade in tumor and infectious processes with limited success. However, the discovery of eflornithine (DFMO) as a curative drug against sleeping sickness encouraged researchers to develop new molecules against these diseases. Polyamine synthesis inhibitors have also provided insight into the peculiarities of this pathway between the host and the parasite, and also among different trypanosomatid species, thus allowing the search for new specific chemical entities aimed to treat these diseases and leading to the investigation of target-based scaffolds. The main molecular targets include the enzymes involved in polyamine biosynthesis (ornithine decarboxylase, S-adenosylmethionine decarboxylase and spermidine synthase), enzymes participating in their uptake from the environment, and the enzymes involved in the redox balance of the parasite. In this review, we summarize the research behind polyamine-based treatments, the current trends, and the main challenges in this field.
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Affiliation(s)
- Yolanda Pérez-Pertejo
- Departamento de Ciencias Biomédicas, Campus de Vegazana s/n, Universidad de León, 24071 León, Spain; (Y.P.-P.); (C.G.-E.); (R.M.R.)
- Instituto de Biomedicina (IBIOMED), Campus de Vegazana s/n, Universidad de León, 24071 León, Spain
| | - Carlos García-Estrada
- Departamento de Ciencias Biomédicas, Campus de Vegazana s/n, Universidad de León, 24071 León, Spain; (Y.P.-P.); (C.G.-E.); (R.M.R.)
- Instituto de Biomedicina (IBIOMED), Campus de Vegazana s/n, Universidad de León, 24071 León, Spain
| | | | - Sankaranarayanan Murugesan
- Medicinal Chemistry Research Laboratory, Department of Pharmacy, Birla Institute of Technology and Science-Pilani, Pilani 333031, India;
| | - Rosa M. Reguera
- Departamento de Ciencias Biomédicas, Campus de Vegazana s/n, Universidad de León, 24071 León, Spain; (Y.P.-P.); (C.G.-E.); (R.M.R.)
- Instituto de Biomedicina (IBIOMED), Campus de Vegazana s/n, Universidad de León, 24071 León, Spain
| | - Rafael Balaña-Fouce
- Departamento de Ciencias Biomédicas, Campus de Vegazana s/n, Universidad de León, 24071 León, Spain; (Y.P.-P.); (C.G.-E.); (R.M.R.)
- Instituto de Biomedicina (IBIOMED), Campus de Vegazana s/n, Universidad de León, 24071 León, Spain
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Li QZ, Zuo ZW, Zhou ZR, Ji Y. Polyamine homeostasis-based strategies for cancer: The role of combination regimens. Eur J Pharmacol 2021; 910:174456. [PMID: 34464603 DOI: 10.1016/j.ejphar.2021.174456] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 08/14/2021] [Accepted: 08/26/2021] [Indexed: 01/07/2023]
Abstract
Spermine, spermidine and putrescine polyamines are naturally occurring ubiquitous positively charged amines and are essential metabolites for biological functions in our life. These compounds play a crucial role in many cell processes, including cellular proliferation, growth, and differentiation. Intracellular levels of polyamines depend on their biosynthesis, transport and degradation. Polyamine levels are high in cancer cells, which leads to the promotion of tumor growth, invasion and metastasis. Targeting polyamine metabolism as an anticancer strategy is considerably rational. Due to compensatory mechanisms, a single strategy does not achieve satisfactory clinical effects when using a single agent. Combination regimens are more clinically promising for cancer chemoprevention because they work synergistically with causing little or no adverse effects due to each individual agent being used at lower doses. Moreover, bioactive substances have advantages over single chemical agents because they can affect multiple targets. In this review, we discuss anticancer strategies targeting polyamine metabolism and describe how combination treatments and effective natural active ingredients are promising therapies. The existing research suggests that polyamine metabolic enzymes are important therapeutic targets and that combination therapies can be more effective than monotherapies based on polyamine depletion.
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Affiliation(s)
- Qi-Zhang Li
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Industrial Fermentation (Ministry of Education), Institute of Biomedical and Pharmaceutical Sciences, Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, Hubei, 430068, PR China.
| | - Zan-Wen Zuo
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Industrial Fermentation (Ministry of Education), Institute of Biomedical and Pharmaceutical Sciences, Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, Hubei, 430068, PR China
| | - Ze-Rong Zhou
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Industrial Fermentation (Ministry of Education), Institute of Biomedical and Pharmaceutical Sciences, Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, Hubei, 430068, PR China
| | - Yan Ji
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Industrial Fermentation (Ministry of Education), Institute of Biomedical and Pharmaceutical Sciences, Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, Hubei, 430068, PR China
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Oncology Therapeutics Targeting the Metabolism of Amino Acids. Cells 2020; 9:cells9081904. [PMID: 32824193 PMCID: PMC7463463 DOI: 10.3390/cells9081904] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/12/2020] [Accepted: 08/13/2020] [Indexed: 12/19/2022] Open
Abstract
Amino acid metabolism promotes cancer cell proliferation and survival by supporting building block synthesis, producing reducing agents to mitigate oxidative stress, and generating immunosuppressive metabolites for immune evasion. Malignant cells rewire amino acid metabolism to maximize their access to nutrients. Amino acid transporter expression is upregulated to acquire amino acids from the extracellular environment. Under nutrient depleted conditions, macropinocytosis can be activated where proteins from the extracellular environment are engulfed and degraded into the constituent amino acids. The demand for non-essential amino acids (NEAAs) can be met through de novo synthesis pathways. Cancer cells can alter various signaling pathways to boost amino acid usage for the generation of nucleotides, reactive oxygen species (ROS) scavenging molecules, and oncometabolites. The importance of amino acid metabolism in cancer proliferation makes it a potential target for therapeutic intervention, including via small molecules and antibodies. In this review, we will delineate the targets related to amino acid metabolism and promising therapeutic approaches.
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Pardali V, Giannakopoulou E, Balourdas DI, Myrianthopoulos V, Taylor MC, Šekutor M, Mlinarić-Majerski K, Kelly JM, Zoidis G. Lipophilic Guanylhydrazone Analogues as Promising Trypanocidal Agents: An Extended SAR Study. Curr Pharm Des 2020; 26:838-866. [DOI: 10.2174/1381612826666200210150127] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 11/19/2019] [Indexed: 12/18/2022]
Abstract
In this report, we extend the SAR analysis of a number of lipophilic guanylhydrazone analogues with
respect to in vitro growth inhibition of Trypanosoma brucei and Trypanosoma cruzi. Sleeping sickness and Chagas
disease, caused by the tropical parasites T. brucei and T. cruzi, constitute a significant socioeconomic burden
in low-income countries of sub-Saharan Africa and Latin America, respectively. Drug development is underfunded.
Moreover, current treatments are outdated and difficult to administer, while drug resistance is an emerging
concern. The synthesis of adamantane-based compounds that have potential as antitrypanosomal agents is
extensively reviewed. The critical role of the adamantane ring was further investigated by synthesizing and testing
a number of novel lipophilic guanylhydrazones. The introduction of hydrophobic bulky substituents onto the
adamantane ring generated the most active analogues, illustrating the synergistic effect of the lipophilic character
of the C1 side chain and guanylhydrazone moiety on trypanocidal activity. The n-decyl C1-substituted compound
G8 proved to be the most potent adamantane derivative against T. brucei with activity in the nanomolar range
(EC50=90 nM). Molecular simulations were also performed to better understand the structure-activity relationships
between the studied guanylhydrazone analogues and their potential enzyme target.
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Affiliation(s)
- Vasiliki Pardali
- School of Health Sciences, Department of Pharmacy, Division of Pharmaceutical Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou, GR-15771 Athens, Greece
| | - Erofili Giannakopoulou
- School of Health Sciences, Department of Pharmacy, Division of Pharmaceutical Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou, GR-15771 Athens, Greece
| | - Dimitrios-Ilias Balourdas
- School of Health Sciences, Department of Pharmacy, Division of Pharmaceutical Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou, GR-15771 Athens, Greece
| | - Vassilios Myrianthopoulos
- School of Health Sciences, Department of Pharmacy, Division of Pharmaceutical Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou, GR-15771 Athens, Greece
| | - Martin C. Taylor
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Marina Šekutor
- Department of Organic Chemistry and Biochemistry, Ruder Boskovic Institute, Bijenicka cesta 54, 10 000 Zagreb, Croatia
| | - Kata Mlinarić-Majerski
- Department of Organic Chemistry and Biochemistry, Ruder Boskovic Institute, Bijenicka cesta 54, 10 000 Zagreb, Croatia
| | - John M. Kelly
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Grigoris Zoidis
- School of Health Sciences, Department of Pharmacy, Division of Pharmaceutical Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou, GR-15771 Athens, Greece
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Patel MM, Volkov OA, Leija C, Lemoff A, Phillips MA. A dual regulatory circuit consisting of S-adenosylmethionine decarboxylase protein and its reaction product controls expression of the paralogous activator prozyme in Trypanosoma brucei. PLoS Pathog 2018; 14:e1007404. [PMID: 30365568 PMCID: PMC6221367 DOI: 10.1371/journal.ppat.1007404] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 11/07/2018] [Accepted: 10/12/2018] [Indexed: 01/12/2023] Open
Abstract
Polyamines are essential for cell growth of eukaryotes including the etiologic agent of human African trypanosomiasis (HAT), Trypanosoma brucei. In trypanosomatids, a key enzyme in the polyamine biosynthetic pathway, S-adenosylmethionine decarboxylase (TbAdoMetDC) heterodimerizes with a unique catalytically-dead paralog called prozyme to form the active enzyme complex. In higher eukaryotes, polyamine metabolism is subject to tight feedback regulation by spermidine-dependent mechanisms that are absent in trypanosomatids. Instead, in T. brucei an alternative regulatory strategy based on TbAdoMetDC prozyme has evolved. We previously demonstrated that prozyme protein levels increase in response to loss of TbAdoMetDC activity. Herein, we show that prozyme levels are under translational control by monitoring incorporation of deuterated leucine into nascent prozyme protein. We furthermore identify pathway factors that regulate prozyme mRNA translation. We find evidence for a regulatory feedback mechanism in which TbAdoMetDC protein and decarboxylated AdoMet (dcAdoMet) act as suppressors of prozyme translation. In TbAdoMetDC null cells expressing the human AdoMetDC enzyme, prozyme levels are constitutively upregulated. Wild-type prozyme levels are restored by complementation with either TbAdoMetDC or an active site mutant, suggesting that TbAdoMetDC possesses an enzyme activity-independent function that inhibits prozyme translation. Depletion of dcAdoMet pools by three independent strategies: inhibition/knockdown of TbAdoMetDC, knockdown of AdoMet synthase, or methionine starvation, each cause prozyme upregulation, providing independent evidence that dcAdoMet functions as a metabolic signal for regulation of the polyamine pathway in T. brucei. These findings highlight a potential regulatory paradigm employing enzymes and pseudoenzymes that may have broad implications in biology. Trypanosoma brucei is a single-celled eukaryotic pathogen and the causative agent of human African trypanosomiasis (HAT). Polyamines are organic polycations that are essential for growth in T. brucei to facilitate protein translation and to maintain redox homeostasis. The pathway is the target of eflornithine, a current frontline therapy for treatment of HAT. Polyamine biosynthetic enzymes are regulated at multiple levels in mammals (e.g. transcription, translation and protein turnover), but in contrast, T. brucei lacks these mechanisms. Instead in T. brucei a central enzyme in polyamine metabolism called AdoMetDC must form a complex with a sister protein (termed a pseudoenzyme) to be active. Herein, we show that cellular levels of this sister protein we call prozyme are in turn feedback regulated by both AdoMetDC and by its reaction product in response to cell treatments that reduce pathway output. This regulatory paradigm highlights how pseudoenzymes can evolve to play an important role in metabolic pathway regulation and in organismal fitness.
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Affiliation(s)
- Manish M. Patel
- Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Harry Hines Blvd, Dallas, TX, United States of America
| | - Oleg A. Volkov
- Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Harry Hines Blvd, Dallas, TX, United States of America
| | - Christopher Leija
- Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Harry Hines Blvd, Dallas, TX, United States of America
| | - Andrew Lemoff
- Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Harry Hines Blvd, Dallas, TX, United States of America
| | - Margaret A. Phillips
- Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Harry Hines Blvd, Dallas, TX, United States of America
- * E-mail:
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6
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Abstract
Polyamines are polycationic organic amines that are required for all eukaryotic life, exemplified by the polyamine spermidine, which plays an essential role in translation. They also play more specialized roles that differ across species, and their chemical versatility has been fully exploited during the evolution of protozoan pathogens. These eukaryotic pathogens, which cause some of the most globally widespread infectious diseases, have acquired species-specific polyamine-derived metabolites with essential cellular functions and have evolved unique mechanisms that regulate their core polyamine biosynthetic pathways. Many of these parasitic species have lost enzymes and or transporters from the polyamine metabolic pathway that are found in the human host. These pathway differences have prompted drug discovery efforts to target the parasite polyamine pathways, and indeed, the only clinically approved drug targeting the polyamine biosynthetic pathway is used to manage human African trypanosomiasis. This Minireview will primarily focus on polyamine metabolism and function in Trypanosoma, Leishmania, and Plasmodium species, which are the causative agents of human African trypanosomiasis (HAT) and Chagas disease, Leishmaniasis, and malaria, respectively. Aspects of polyamine metabolism across a diverse group of protozoan pathogens will also be explored.
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Affiliation(s)
- Margaret A Phillips
- From the Departments of Biochemistry and Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390-9038
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7
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Volkov OA, Brockway AJ, Wring SA, Peel M, Chen Z, Phillips MA, De Brabander JK. Species-Selective Pyrimidineamine Inhibitors of Trypanosoma brucei S-Adenosylmethionine Decarboxylase. J Med Chem 2018; 61:1182-1203. [PMID: 29271204 DOI: 10.1021/acs.jmedchem.7b01654] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
New therapeutic options are needed for treatment of human African trypanosomiasis (HAT) caused by protozoan parasite Trypanosoma brucei. S-Adenosylmethionine decarboxylase (AdoMetDC) is an essential enzyme in the polyamine pathway of T. brucei. Previous attempts to target this enzyme were thwarted by the lack of brain penetration of the most advanced series. Herein, we describe a T. brucei AdoMetDC inhibitor series based on a pyrimidineamine pharmacophore that we identified by target-based high-throughput screening. The pyrimidineamines showed selectivity for T. brucei AdoMetDC over the human enzyme, inhibited parasite growth in whole-cell assay, and had good predicted blood-brain barrier penetration. The medicinal chemistry program elucidated structure-activity relationships within the series. Features of the series that were required for binding were revealed by determining the X-ray crystal structure of TbAdoMetDC bound to one analog. The pyrimidineamine series provides a novel starting point for an anti-HAT lead optimization.
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Affiliation(s)
| | | | - Stephen A Wring
- Scynexis, Inc. (now Avista Pharma Solutions) , 3501 Tricenter Boulevard, Suite C, Durham, North Carolina 27713, United States
| | - Michael Peel
- Scynexis, Inc. (now Avista Pharma Solutions) , 3501 Tricenter Boulevard, Suite C, Durham, North Carolina 27713, United States
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Franco J, Sardi F, Szilágyi L, Kövér KE, Fehér K, Comini MA. Diglycosyl diselenides alter redox homeostasis and glucose consumption of infective African trypanosomes. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2017; 7:303-313. [PMID: 28826037 PMCID: PMC5565762 DOI: 10.1016/j.ijpddr.2017.08.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 08/04/2017] [Accepted: 08/08/2017] [Indexed: 12/16/2022]
Abstract
With the aim to develop compounds able to target multiple metabolic pathways and, thus, to lower the chances of drug resistance, we investigated the anti-trypanosomal activity and selectivity of a series of symmetric diglycosyl diselenides and disulfides. Of 18 compounds tested the fully acetylated forms of di-β-D-glucopyranosyl and di-β-D-galactopyranosyl diselenides (13 and 15, respectively) displayed strong growth inhibition against the bloodstream stage of African trypanosomes (EC50 0.54 μM for 13 and 1.49 μM for 15) although with rather low selectivity (SI < 10 assayed with murine macrophages). Nonacetylated versions of the same sugar diselenides proved to be, however, much less efficient or completely inactive to suppress trypanosome growth. Significantly, the galactosyl (15), and to a minor extent the glucosyl (13), derivative inhibited glucose catabolism but not its uptake. Both compounds induced redox unbalance in the pathogen. In vitro NMR analysis indicated that diglycosyl diselenides react with glutathione, under physiological conditions, via formation of selenenylsulfide bonds. Our results suggest that non-specific cellular targets as well as actors of the glucose and the redox metabolism of the parasite may be affected. These molecules are therefore promising leads for the development of novel multitarget antitrypanosomal agents. Acetylated diglycosyl diselenides inhibit the proliferation of infective Trypanosoma brucei. A galactosyl derivative impairs parasite' glucose consumption and redox homeostasis. Diglycosyl diselenides react covalently with glutathione under mild conditions.. Acetylated diglycosyl diselenides represent multitarget antitrypanosomal candidates.
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Affiliation(s)
- Jaime Franco
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, 11400 Montevideo, Uruguay; Cátedra de Química Farmacéutica, Departamento de Química Orgánica, Facultad de Química, Universidad de La República, Gral. Flores 2124, 11800 Montevideo, Uruguay
| | - Florencia Sardi
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, 11400 Montevideo, Uruguay
| | - László Szilágyi
- Department of Chemistry, Faculty of Science and Technology, University of Debrecen, H-4010 Debrecen, Pf. 20, Hungary
| | - Katalin E Kövér
- Department of Chemistry, Faculty of Science and Technology, University of Debrecen, H-4010 Debrecen, Pf. 20, Hungary
| | - Krisztina Fehér
- Department of Organic and Macromolecular Chemistry, University of Gent, Krijgslaan 281 S4, B-9000 Gent, Belgium.
| | - Marcelo A Comini
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, 11400 Montevideo, Uruguay.
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Synthesis and evaluation of analogs of 5'-(((Z)-4-amino-2-butenyl)methylamino)-5'-deoxyadenosine (MDL 73811, or AbeAdo) - An inhibitor of S-adenosylmethionine decarboxylase with antitrypanosomal activity. Bioorg Med Chem 2017; 25:5433-5440. [PMID: 28807574 DOI: 10.1016/j.bmc.2017.07.063] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 07/31/2017] [Indexed: 01/18/2023]
Abstract
We describe our efforts to improve the pharmacokinetic properties of a mechanism-based suicide inhibitor of the polyamine biosynthetic enzyme S-adenosylmethionine decarboxylase (AdoMetDC), essential for the survival of the eukaryotic parasite Trypanosoma brucei responsible for Human African Trypanosomiasis (HAT). The lead compound, 5'-(((Z)-4-amino-2-butenyl)methylamino)-5'-deoxyadenosine (1, also known as MDL 73811, or AbeAdo), has curative efficacy at a low dosage in a hemolymphatic model of HAT but displayed no demonstrable effect in a mouse model of the CNS stage of HAT due to poor blood-brain barrier permeation. Therefore, we prepared and evaluated an extensive set of analogs with modifications in the aminobutenyl side chain, the 5'-amine, the ribose, and the purine fragments. Although we gained valuable structure-activity insights from this comprehensive dataset, we did not gain traction on improving the prospects for CNS penetration while retaining the potent antiparasitic activity and metabolic stability of the lead compound 1.
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Volkov OA, Cosner CC, Brockway AJ, Kramer M, Booker M, Zhong S, Ketcherside A, Wei S, Longgood J, McCoy M, Richardson TE, Wring SA, Peel M, Klinger JD, Posner BA, De Brabander JK, Phillips MA. Identification of Trypanosoma brucei AdoMetDC Inhibitors Using a High-Throughput Mass Spectrometry-Based Assay. ACS Infect Dis 2017; 3:512-526. [PMID: 28350440 DOI: 10.1021/acsinfecdis.7b00022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Human African trypanosomiasis (HAT) is a fatal infectious disease caused by the eukaryotic pathogen Trypanosoma brucei (Tb). Available treatments are difficult to administer and have significant safety issues. S-Adenosylmethionine decarboxylase (AdoMetDC) is an essential enzyme in the parasite polyamine biosynthetic pathway. Previous attempts to develop TbAdoMetDC inhibitors into anti-HAT therapies failed due to poor brain exposure. Here, we describe a large screening campaign of two small-molecule libraries (∼400,000 compounds) employing a new high-throughput (∼7 s per sample) mass spectrometry-based assay for AdoMetDC activity. As a result of primary screening, followed by hit confirmation and validation, we identified 13 new classes of reversible TbAdoMetDC inhibitors with low-micromolar potency (IC50) against both TbAdoMetDC and T. brucei parasite cells. The majority of these compounds were >10-fold selective against the human enzyme. Importantly, compounds from four classes demonstrated high propensity to cross the blood-brain barrier in a cell monolayer assay. Biochemical analysis demonstrated that compounds from eight classes inhibited intracellular TbAdoMetDC in the parasite, although evidence for a secondary off-target component was also present. The discovery of several new TbAdoMetDC inhibitor chemotypes provides new hits for lead optimization programs aimed to deliver a novel treatment for HAT.
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Affiliation(s)
| | | | | | - Martin Kramer
- Genzyme Corp. (now Sanofi Genzyme), 153 Second Avenue, Waltham, Massachusetts 02451-1122, United States
| | - Michael Booker
- Genzyme Corp. (now Sanofi Genzyme), 153 Second Avenue, Waltham, Massachusetts 02451-1122, United States
| | | | | | | | | | | | - Thomas E. Richardson
- Scynexis, Inc. (now Avista Pharma Solutions), 3501 Tricenter Boulevard, Suite
C, Durham, North Carolina 27713, United States
| | - Stephen A. Wring
- Scynexis, Inc. (now Avista Pharma Solutions), 3501 Tricenter Boulevard, Suite
C, Durham, North Carolina 27713, United States
| | - Michael Peel
- Scynexis, Inc. (now Avista Pharma Solutions), 3501 Tricenter Boulevard, Suite
C, Durham, North Carolina 27713, United States
| | - Jeffrey D. Klinger
- Genzyme Corp. (now Sanofi Genzyme), 153 Second Avenue, Waltham, Massachusetts 02451-1122, United States
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11
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Patrick DA, Gillespie JR, McQueen J, Hulverson MA, Ranade RM, Creason SA, Herbst ZM, Gelb MH, Buckner FS, Tidwell RR. Urea Derivatives of 2-Aryl-benzothiazol-5-amines: A New Class of Potential Drugs for Human African Trypanosomiasis. J Med Chem 2016; 60:957-971. [PMID: 27992217 DOI: 10.1021/acs.jmedchem.6b01163] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A previous publication from this lab (Patrick, et al. Bioorg. Med. Chem. 2016, 24 , 2451 - 2465 ) explored the antitrypanosomal activities of novel derivatives of 2-(2-benzamido)ethyl-4-phenylthiazole (1), which had been identified as a hit against Trypanosoma brucei, the causative agent of human African trypanosomiasis. While a number of these compounds, particularly the urea analogues, were quite potent, these molecules as a whole exhibited poor metabolic stability. The present work describes the synthesis of 65 new analogues arising from medicinal chemistry optimization at different sites on the molecule. The most promising compounds were the urea derivatives of 2-aryl-benzothiazol-5-amines. One such analogue, (S)-2-(3,4-difluorophenyl)-5-(3-fluoro-N-pyrrolidylamido)benzothiazole (57) was chosen for in vivo efficacy studies based upon in vitro activity, metabolic stability, and brain penetration. This compound attained 5/5 cures in murine models of both early and late stage human African trypanosomiasis, representing a new lead for the development of drugs to combat this neglected disease.
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Affiliation(s)
- Donald A Patrick
- Department of Pathology and Laboratory Medicine, University of North Carolina , Chapel Hill, North Carolina 27599, United States
| | | | | | | | | | | | | | | | | | - Richard R Tidwell
- Department of Pathology and Laboratory Medicine, University of North Carolina , Chapel Hill, North Carolina 27599, United States
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12
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Hasne MP, Soysa R, Ullman B. The Trypanosoma cruzi Diamine Transporter Is Essential for Robust Infection of Mammalian Cells. PLoS One 2016; 11:e0152715. [PMID: 27050410 PMCID: PMC4822861 DOI: 10.1371/journal.pone.0152715] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 03/17/2016] [Indexed: 12/01/2022] Open
Abstract
Trypanosoma cruzi is incapable of synthesizing putrescine or cadaverine de novo, and, therefore, salvage of polyamines from the host milieu is an obligatory nutritional function for the parasite. A high-affinity diamine transporter (TcPOT1) from T. cruzi has been identified previously that recognizes both putrescine and cadaverine as ligands. In order to assess the functional role of TcPOT1 in intact parasites, a Δtcpot1 null mutant was constructed by targeted gene replacement and characterized. The Δtcpot1 mutant lacked high-affinity putrescine-cadaverine transport capability but retained the capacity to transport diamines via a non-saturable, low-affinity mechanism. Transport of spermidine and arginine was not impacted by the Δtcpot1 lesion. The Δtcpot1 cell line exhibited a significant but not total defect in its ability to subsist in Vero cells, although initial infection rates were not affected by the lesion. These findings reveal that TcPOT1 is the sole high-affinity diamine permease in T. cruzi, that genetic obliteration of TcPOT1 impairs the ability of the parasite to maintain a robust infection in mammalian cells, and that a secondary low-affinity uptake mechanism for this key parasite nutrient is operative but insufficient for optimal infection.
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Affiliation(s)
- Marie-Pierre Hasne
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, Oregon, United States of America
- * E-mail:
| | - Radika Soysa
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Buddy Ullman
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, Oregon, United States of America
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Novel protein-protein interaction between spermidine synthase and S-adenosylmethionine decarboxylase from Leishmania donovani. Biochem Biophys Res Commun 2014; 456:637-42. [PMID: 25511700 DOI: 10.1016/j.bbrc.2014.12.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 12/03/2014] [Indexed: 11/23/2022]
Abstract
Polyamine biosynthesis pathway has long been considered an essential drug target for trypanosomatids including Leishmania. S-adenosylmethionine decarboxylase (AdoMetDc) and spermidine synthase (SpdSyn) are enzymes of this pathway that catalyze successive steps, with the product of the former, decarboxylated S-adenosylmethionine (dcSAM), acting as an aminopropyl donor for the latter enzyme. Here we have explored the possibility of and identified the protein-protein interaction between SpdSyn and AdoMetDc. The protein-protein interaction has been identified using GST pull down assay. Isothermal titration calorimetry reveals that the interaction is thermodynamically favorable. Fluorescence spectroscopy studies also confirms the interaction, with SpdSyn exhibiting a change in tertiary structure with increasing concentrations of AdoMetDc. Size exclusion chromatography suggests the presence of the complex as a hetero-oligomer. Taken together, these results suggest that the enzymes indeed form a heteromer. Computational analyses suggest that this complex differs significantly from the corresponding human complex, implying that this complex could be a better therapeutic target than the individual enzymes.
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le Roux D, Burger PB, Niemand J, Grobler A, Urbán P, Fernàndez-Busquets X, Barker RH, Serrano AE, I Louw A, Birkholtz LM. Novel S-adenosyl-L-methionine decarboxylase inhibitors as potent antiproliferative agents against intraerythrocytic Plasmodium falciparum parasites. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2013; 4:28-36. [PMID: 24596666 PMCID: PMC3940083 DOI: 10.1016/j.ijpddr.2013.11.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 11/19/2013] [Accepted: 11/20/2013] [Indexed: 12/31/2022]
Abstract
S-adenosyl-l-methionine decarboxylase (AdoMetDC) in the polyamine biosynthesis pathway has been identified as a suitable drug target in Plasmodium falciparum parasites, which causes the most lethal form of malaria. Derivatives of an irreversible inhibitor of this enzyme, 5'-{[(Z)-4-amino-2-butenyl]methylamino}-5'-deoxyadenosine (MDL73811), have been developed with improved pharmacokinetic profiles and activity against related parasites, Trypanosoma brucei. Here, these derivatives were assayed for inhibition of AdoMetDC from P. falciparum parasites and the methylated derivative, 8-methyl-5'-{[(Z)-4-aminobut-2-enyl]methylamino}-5'-deoxyadenosine (Genz-644131) was shown to be the most active. The in vitro efficacy of Genz-644131 was markedly increased by nanoencapsulation in immunoliposomes, which specifically targeted intraerythrocytic P. falciparum parasites.
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Affiliation(s)
- Dina le Roux
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Pieter B Burger
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Jandeli Niemand
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Anne Grobler
- DST/NWU Preclinical Drug Development Platform, North-West University, Potchefstroom 2531, South Africa
| | - Patricia Urbán
- Nanobioengineering Group, Institute for Bioengineering of Catalonia, Baldiri Reixac 10-12, Barcelona E08028, Spain ; Barcelona Centre for International Health Research (CRESIB), Hospital Clínic-Universitat de Barcelona, Rosselló 149-153, Barcelona E08036, Spain ; Biomolecular Interactions Team, Nanoscience and Nanotechnology Institute (IN2UB), University of Barcelona, Martí i Franquès 1, Barcelona E08028, Spain
| | - Xavier Fernàndez-Busquets
- Nanobioengineering Group, Institute for Bioengineering of Catalonia, Baldiri Reixac 10-12, Barcelona E08028, Spain ; Barcelona Centre for International Health Research (CRESIB), Hospital Clínic-Universitat de Barcelona, Rosselló 149-153, Barcelona E08036, Spain ; Biomolecular Interactions Team, Nanoscience and Nanotechnology Institute (IN2UB), University of Barcelona, Martí i Franquès 1, Barcelona E08028, Spain
| | - Robert H Barker
- Genzyme Corporation, 153 Second Avenue, Waltham, MA 02451, USA
| | - Adelfa E Serrano
- University of Puerto Rico-School of Medicine, Department of Microbiology and Medical Zoology, P.O. Box 365067, San Juan PR 00936-5067, Puerto Rico
| | - Abraham I Louw
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
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Jones AJ, Grkovic T, Sykes ML, Avery VM. Trypanocidal activity of marine natural products. Mar Drugs 2013; 11:4058-82. [PMID: 24152565 PMCID: PMC3826150 DOI: 10.3390/md11104058] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 10/09/2013] [Accepted: 10/10/2013] [Indexed: 12/21/2022] Open
Abstract
Marine natural products are a diverse, unique collection of compounds with immense therapeutic potential. This has resulted in these molecules being evaluated for a number of different disease indications including the neglected protozoan diseases, human African trypanosomiasis and Chagas disease, for which very few drugs are currently available. This article will review the marine natural products for which activity against the kinetoplastid parasites; Trypanosoma brucei brucei, T.b. rhodesiense and T. cruzi has been reported. As it is important to know the selectivity of a compound when evaluating its trypanocidal activity, this article will only cover molecules which have simultaneously been tested for cytotoxicity against a mammalian cell line. Compounds have been grouped according to their chemical structure and representative examples from each class were selected for detailed discussion.
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Affiliation(s)
- Amy J Jones
- Eskitis Institute for Drug Discovery, Griffith University, Nathan, Brisbane 4111, Australia.
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Xiao Y, Nguyen S, Kim SH, Volkov OA, Tu BP, Phillips MA. Product feedback regulation implicated in translational control of the Trypanosoma brucei S-adenosylmethionine decarboxylase regulatory subunit prozyme. Mol Microbiol 2013; 88:846-61. [PMID: 23634831 DOI: 10.1111/mmi.12226] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/04/2013] [Indexed: 12/12/2022]
Abstract
Human African sleeping sickness (HAT) is caused by the parasitic protozoan Trypanosoma brucei. Polyamine biosynthesis is an important drug target in the treatment of HAT. Previously we showed that trypanosomatid S-adenosylmethionine decarboxylase (AdoMetDC), a key enzyme for biosynthesis of the polyamine spermidine, is activated by heterodimer formation with an inactive paralogue termed prozyme. Furthermore, prozyme protein levels were regulated in response to reduced AdoMetDC activity. Herein we show that T. brucei encodes three prozyme transcripts. The 3'UTRs of these transcripts were mapped and chloramphenicol acetyltransferase (CAT) reporter constructs were used to identify a 1.2 kb region that contained a 3'UTR prozyme regulatory element sufficient to upregulate CAT protein levels (but not RNA) upon AdoMetDC inhibition, supporting the hypothesis that prozyme expression is regulated translationally. To gain insight into trans-acting factors, genetic rescue of AdoMetDC RNAi knock-down lines with human AdoMetDC was performed leading to rescue of the cell growth block, and restoration of prozyme protein to wild-type levels. Metabolite analysis showed that prozyme protein levels were inversely proportional to intracellular levels of decarboxylated AdoMet (dcAdoMet). These data suggest that prozyme translation may be regulated by dcAdoMet, a metabolite not previously identified to play a regulatory role.
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Affiliation(s)
- Yanjing Xiao
- Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9041, USA
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Vigueira PA, Ray SS, Martin BA, Ligon MM, Paul KS. Effects of the green tea catechin (-)-epigallocatechin gallate on Trypanosoma brucei. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2012; 2:225-9. [PMID: 24533284 DOI: 10.1016/j.ijpddr.2012.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 09/11/2012] [Accepted: 09/13/2012] [Indexed: 12/11/2022]
Abstract
The current pharmacopeia to treat the lethal human and animal diseases caused by the protozoan parasite Trypanosoma brucei remains limited. The parasite's ability to undergo antigenic variation represents a considerable barrier to vaccine development, making the identification of new drug targets extremely important. Recent studies have demonstrated that fatty acid synthesis is important for growth and virulence of Trypanosoma brucei brucei, suggesting this pathway may have therapeutic potential. The first committed step of fatty acid synthesis is catalyzed by acetyl-CoA carboxylase (ACC), which is a known target of (-)-epigallocatechin-3-gallate (EGCG), an active polyphenol compound found in green tea. EGCG exerts its effects on ACC through activation of AMP-dependent protein kinase, which phosphorylates and inhibits ACC. We found that EGCG inhibited TbACC activity with an EC50 of 37 μM and 55 μM for bloodstream form and procyclic form lysates, respectively. Treatment with 100 μM EGCG induced a 4.7- and 1.7- fold increase in TbACC phosphorylation in bloodstream form and procyclic lysates. EGCG also inhibited the growth of bloodstream and procyclic parasites in culture, with a 48 h EC50 of 33 μM and 27 μM, respectively, which is greater than the EGCG plasma levels typically achievable in humans through oral dosing. Daily intraperitoneal administration of EGCG did not reduce the virulence of an acute mouse model of T. b. brucei infection. These data suggest a reduced potential for EGCG to treat T. brucei infections, but suggest that EGCG may prove to be useful as a tool to probe ACC regulation.
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Affiliation(s)
- Patrick A Vigueira
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA
| | - Sunayan S Ray
- Department of Genetics & Biochemistry, Clemson University, Clemson, SC 29634, USA
| | - Ben A Martin
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA
| | - Marianne M Ligon
- Department of Genetics & Biochemistry, Clemson University, Clemson, SC 29634, USA
| | - Kimberly S Paul
- Department of Genetics & Biochemistry, Clemson University, Clemson, SC 29634, USA
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Willert E, Phillips MA. Regulation and function of polyamines in African trypanosomes. Trends Parasitol 2011; 28:66-72. [PMID: 22192816 DOI: 10.1016/j.pt.2011.11.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 10/31/2011] [Accepted: 11/01/2011] [Indexed: 02/03/2023]
Abstract
The polyamine biosynthetic pathway is an important drug target for the treatment of human African trypanosomiasis (HAT), raising interest in understanding polyamine function and their mechanism of regulation. Polyamine levels are tightly controlled in mammalian cells, but similar regulatory mechanisms appear absent in trypanosomes. Instead trypanosomatid S-adenosylmethionine decarboxylase (AdoMetDC), which catalyzes a key step in the biosynthesis of the polyamine spermidine, is activated by dimerization with an inducible protein termed prozyme. Prozyme is an inactive paralog of the active AdoMetDC enzyme that evolved by gene duplication and is found only in the trypanosomatids. In Trypanosoma brucei, AdoMetDC activity appears to be controlled by regulation of prozyme protein levels, potentially at the translational level.
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Affiliation(s)
- Erin Willert
- Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, 6001 Forest Park Road, Dallas, TX 75390-9041, USA
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Abstract
Genetic lesions in the polyamine biosynthetic pathway of Leishmania donovani, the causal agent of visceral leishmaniasis, are conditionally lethal mutations that render the insect vector form of the parasite auxotrophic for polyamines. Recently, we have demonstrated that a Δodc L. donovani null mutant lacking ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine biosynthesis, was profoundly compromised in its ability to infect mice, indicating that ODC is essential for the infectious mammalian stage of the parasite and further validating the enzyme as a possible drug target. To assess whether other components of the polyamine biosynthetic pathway were also essential for parasite virulence, a cell line deficient in spermidine synthase (SPDSYN), the enzyme that converts putrescine to spermidine, was created by double-targeted gene replacement within a virulent L. donovani background. This Δspdsyn strain was auxotrophic for polyamines, required spermidine for growth in its insect vector form, and was adversely impacted in its ability to infect mice. These findings establish that SPDSYN, like ODC, is essential for maintaining a robust infection in mammals and indicate that pharmacologic inhibition of SPDSYN, and perhaps all components of the polyamine biosynthetic pathway, is a valid therapeutic strategy for the treatment of visceral and, potentially, other forms of leishmaniasis.
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Jacobs RT, Nare B, Phillips MA. State of the art in African trypanosome drug discovery. Curr Top Med Chem 2011; 11:1255-74. [PMID: 21401507 PMCID: PMC3101707 DOI: 10.2174/156802611795429167] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Accepted: 11/25/2010] [Indexed: 11/22/2022]
Abstract
African sleeping sickness is endemic in sub-Saharan Africa where the WHO estimates that 60 million people are at risk for the disease. Human African trypanosomiasis (HAT) is 100% fatal if untreated and the current drug therapies have significant limitations due to toxicity and difficult treatment regimes. No new chemical agents have been approved since eflornithine in 1990. The pentamidine analog DB289, which was in late stage clinical trials for the treatment of early stage HAT recently failed due to toxicity issues. A new protocol for the treatment of late-stage T. brucei gambiense that uses combination nifurtomox/eflornithine (NECT) was recently shown to have better safety and efficacy than eflornithine alone, while being easier to administer. This breakthrough represents the only new therapy for HAT since the approval of eflornithine. A number of research programs are on going to exploit the unusual biochemical pathways in the parasite to identify new targets for target based drug discovery programs. HTS efforts are also underway to discover new chemical entities through whole organism screening approaches. A number of inhibitors with anti-trypanosomal activity have been identified by both approaches, but none of the programs are yet at the stage of identifying a preclinical candidate. This dire situation underscores the need for continued effort to identify new chemical agents for the treatment of HAT.
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Affiliation(s)
- Robert T. Jacobs
- SCYNEXIS, Inc., Research Triangle Park, North Carolina 27709-2878
| | - Bakela Nare
- SCYNEXIS, Inc., Research Triangle Park, North Carolina 27709-2878
| | - Margaret A. Phillips
- Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, 6001 Forest Park Rd, Dallas, Texas 75390-9041
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Dridi L, Ahmed Ouameur A, Ouellette M. High affinity S-Adenosylmethionine plasma membrane transporter of Leishmania is a member of the folate biopterin transporter (FBT) family. J Biol Chem 2010; 285:19767-75. [PMID: 20406813 PMCID: PMC2888387 DOI: 10.1074/jbc.m110.114520] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Revised: 04/12/2010] [Indexed: 11/06/2022] Open
Abstract
S-Adenosylmethionine (AdoMet) is an important methyl group donor that plays a central role in many essential biochemical processes. The parasite Leishmania can both synthesize and transport AdoMet. Leishmania cells resistant to the antifolate methotrexate due to a rearrangement in folate biopterin transporter (FBT) genes were cross-resistant to sinefungin, an AdoMet analogue. FBT gene rearrangements were also observed in Leishmania major cells selected for sinefungin resistance. One of the rearranged FBT genes corresponded to the main AdoMet transporter (AdoMetT1) of Leishmania as determined by gene transfection and gene inactivation experiments. AdoMetT1 was determined to be a high affinity plasma membrane transporter expressed constitutively throughout the growth phases of the parasite. Leishmania cells selected for resistance or naturally insensitive to sinefungin had lower expression of AdoMetT1. A new function in one carbon metabolism, also a pathway of interest for chemotherapeutic interventions, is described for a novel class of membrane proteins found in diverse organisms.
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Affiliation(s)
- Larbi Dridi
- From the Centre de Recherche en Infectiologie du CHUL, Université Laval, Québec City, Québec G1V 4G2, Canada
| | - Amin Ahmed Ouameur
- From the Centre de Recherche en Infectiologie du CHUL, Université Laval, Québec City, Québec G1V 4G2, Canada
| | - Marc Ouellette
- From the Centre de Recherche en Infectiologie du CHUL, Université Laval, Québec City, Québec G1V 4G2, Canada
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Jacobs RT, Ding C. Recent Advances in Drug Discovery for Neglected Tropical Diseases Caused by Infective Kinetoplastid Parasites. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2010. [DOI: 10.1016/s0065-7743(10)45017-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Abstract
The protozoan parasitesTrypanosoma bruceiandTrypanosoma cruziare the causative agents of African trypanosomiasis and Chagas disease, respectively. These are debilitating infections that exert a considerable health burden on some of the poorest people on the planet. Treatment of trypanosome infections is dependent on a small number of drugs that have limited efficacy and can cause severe side effects. Here, we review the properties of these drugs and describe new findings on their modes of action and the mechanisms by which resistance can arise. We further outline how a greater understanding of parasite biology is being exploited in the search for novel chemotherapeutic agents. This effort is being facilitated by new research networks that involve academic and biotechnology/pharmaceutical organisations, supported by public–private partnerships, and are bringing a new dynamism and purpose to the search for trypanocidal agents.
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