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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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2
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Jamabo M, Mahlalela M, Edkins AL, Boshoff A. Tackling Sleeping Sickness: Current and Promising Therapeutics and Treatment Strategies. Int J Mol Sci 2023; 24:12529. [PMID: 37569903 PMCID: PMC10420020 DOI: 10.3390/ijms241512529] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/27/2023] [Accepted: 08/03/2023] [Indexed: 08/13/2023] Open
Abstract
Human African trypanosomiasis is a neglected tropical disease caused by the extracellular protozoan parasite Trypanosoma brucei, and targeted for eradication by 2030. The COVID-19 pandemic contributed to the lengthening of the proposed time frame for eliminating human African trypanosomiasis as control programs were interrupted. Armed with extensive antigenic variation and the depletion of the B cell population during an infectious cycle, attempts to develop a vaccine have remained unachievable. With the absence of a vaccine, control of the disease has relied heavily on intensive screening measures and the use of drugs. The chemotherapeutics previously available for disease management were plagued by issues such as toxicity, resistance, and difficulty in administration. The approval of the latest and first oral drug, fexinidazole, is a major chemotherapeutic achievement for the treatment of human African trypanosomiasis in the past few decades. Timely and accurate diagnosis is essential for effective treatment, while poor compliance and resistance remain outstanding challenges. Drug discovery is on-going, and herein we review the recent advances in anti-trypanosomal drug discovery, including novel potential drug targets. The numerous challenges associated with disease eradication will also be addressed.
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Affiliation(s)
- Miebaka Jamabo
- Biotechnology Innovation Centre, Rhodes University, Makhanda 6139, South Africa; (M.J.); (M.M.)
| | - Maduma Mahlalela
- Biotechnology Innovation Centre, Rhodes University, Makhanda 6139, South Africa; (M.J.); (M.M.)
| | - Adrienne L. Edkins
- Department of Biochemistry and Microbiology, Biomedical Biotechnology Research Centre (BioBRU), Rhodes University, Makhanda 6139, South Africa;
| | - Aileen Boshoff
- Biotechnology Innovation Centre, Rhodes University, Makhanda 6139, South Africa; (M.J.); (M.M.)
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3
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Yoshino R, Yasuo N, Hagiwara Y, Ishida T, Inaoka DK, Amano Y, Tateishi Y, Ohno K, Namatame I, Niimi T, Orita M, Kita K, Akiyama Y, Sekijima M. Discovery of a Hidden Trypanosoma cruzi Spermidine Synthase Binding Site and Inhibitors through In Silico, In Vitro, and X-ray Crystallography. ACS OMEGA 2023; 8:25850-25860. [PMID: 37521650 PMCID: PMC10373461 DOI: 10.1021/acsomega.3c01314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 06/28/2023] [Indexed: 08/01/2023]
Abstract
In drug discovery research, the selection of promising binding sites and understanding the binding mode of compounds are crucial fundamental studies. The current understanding of the proteins-ligand binding model extends beyond the simple lock and key model to include the induced-fit model, which alters the conformation to match the shape of the ligand, and the pre-existing equilibrium model, selectively binding structures with high binding affinity from a diverse ensemble of proteins. Although methods for detecting target protein binding sites and virtual screening techniques using docking simulation are well-established, with numerous studies reported, they only consider a very limited number of structures in the diverse ensemble of proteins, as these methods are applied to a single structure. Molecular dynamics (MD) simulation is a method for predicting protein dynamics and can detect potential ensembles of protein binding sites and hidden sites unobservable in a single-point structure. In this study, to demonstrate the utility of virtual screening with protein dynamics, MD simulations were performed on Trypanosoma cruzi spermidine synthase to obtain an ensemble of dominant binding sites with a high probability of existence. The structure of the binding site obtained through MD simulation revealed pockets in addition to the active site that was present in the initial structure. Using the obtained binding site structures, virtual screening of 4.8 million compounds by docking simulation, in vitro assays, and X-ray analysis was conducted, successfully identifying two hit compounds.
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Affiliation(s)
- Ryunosuke Yoshino
- Transborder
Medical Research Center, University of Tsukuba, Tsukuba 305-8577, Japan
- Education
Academy of Computational Life Sciences (ACLS), Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Nobuaki Yasuo
- Tokyo
Tech Academy for Convergence of Materials and Informatics (TAC-MI), Tokyo Institute of Technology, Meguro, Tokyo 152-8550, Japan
| | - Yohsuke Hagiwara
- Education
Academy of Computational Life Sciences (ACLS), Tokyo Institute of Technology, Yokohama 226-8501, Japan
- Medicinal
Chemistry Research Labs, Drug Discovery Research, Astellas Pharma Inc, Miyukigaoka, Tsukuba 305-8585, Japan
| | - Takashi Ishida
- School
of Computing, Tokyo Institute of Technology, Tokyo 152-8550, Japan
| | - Daniel Ken Inaoka
- School of
Tropical Medicine and Global Health, Nagasaki
University, Sakamoto, Nagasaki 852-8523, Japan
- Department
of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Yasushi Amano
- Medicinal
Chemistry Research Labs, Drug Discovery Research, Astellas Pharma Inc, Miyukigaoka, Tsukuba 305-8585, Japan
| | - Yukihiro Tateishi
- Medicinal
Chemistry Research Labs, Drug Discovery Research, Astellas Pharma Inc, Miyukigaoka, Tsukuba 305-8585, Japan
| | - Kazuki Ohno
- Education
Academy of Computational Life Sciences (ACLS), Tokyo Institute of Technology, Yokohama 226-8501, Japan
- Medicinal
Chemistry Research Labs, Drug Discovery Research, Astellas Pharma Inc, Miyukigaoka, Tsukuba 305-8585, Japan
| | - Ichiji Namatame
- Medicinal
Chemistry Research Labs, Drug Discovery Research, Astellas Pharma Inc, Miyukigaoka, Tsukuba 305-8585, Japan
| | - Tatsuya Niimi
- Medicinal
Chemistry Research Labs, Drug Discovery Research, Astellas Pharma Inc, Miyukigaoka, Tsukuba 305-8585, Japan
| | - Masaya Orita
- Medicinal
Chemistry Research Labs, Drug Discovery Research, Astellas Pharma Inc, Miyukigaoka, Tsukuba 305-8585, Japan
| | - Kiyoshi Kita
- School of
Tropical Medicine and Global Health, Nagasaki
University, Sakamoto, Nagasaki 852-8523, Japan
- Department
of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Yutaka Akiyama
- Education
Academy of Computational Life Sciences (ACLS), Tokyo Institute of Technology, Yokohama 226-8501, Japan
- School
of Computing, Tokyo Institute of Technology, Tokyo 152-8550, Japan
| | - Masakazu Sekijima
- Education
Academy of Computational Life Sciences (ACLS), Tokyo Institute of Technology, Yokohama 226-8501, Japan
- School
of Computing, Tokyo Institute of Technology, Tokyo 152-8550, Japan
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4
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Kaiser A. The Role of Spermidine and Its Key Metabolites in Important, Pathogenic Human Viruses and in Parasitic Infections Caused by Plasmodium falciparum and Trypanosoma brucei. Biomolecules 2023; 13:biom13050803. [PMID: 37238673 DOI: 10.3390/biom13050803] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/01/2023] [Accepted: 05/06/2023] [Indexed: 05/28/2023] Open
Abstract
The triamine spermidine is a key metabolite of the polyamine pathway. It plays a crucial role in many infectious diseases caused by viral or parasitic infections. Spermidine and its metabolizing enzymes, i.e., spermidine/spermine-N1-acetyltransferase, spermine oxidase, acetyl polyamine oxidase, and deoxyhypusine synthase, fulfill common functions during infection in parasitic protozoa and viruses which are obligate, intracellular parasites. The competition for this important polyamine between the infected host cell and the pathogen determines the severity of infection in disabling human parasites and pathogenic viruses. Here, we review the impact of spermidine and its metabolites in disease development of the most important, pathogenic human viruses such as SARS-CoV-2, HIV, Ebola, and in the human parasites Plasmodium and Trypanosomes. Moreover, state-of-the-art translational approaches to manipulate spermidine metabolism in the host and the pathogen are discussed to accelerate drug development against these threatful, infectious human diseases.
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Affiliation(s)
- Annette Kaiser
- Medical Research Centre, University of Duisburg-Essen, Hufelandstrasse 55, 45147 Essen, Germany
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5
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Xie J, Pan G, Li Y, Lai L. How protein topology controls allosteric regulations. J Chem Phys 2023; 158:105102. [PMID: 36922138 DOI: 10.1063/5.0138279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Allostery is an important regulatory mechanism of protein functions. Among allosteric proteins, certain protein structure types are more observed. However, how allosteric regulation depends on protein topology remains elusive. In this study, we extracted protein topology graphs at the fold level and found that known allosteric proteins mainly contain multiple domains or subunits and allosteric sites reside more often between two or more domains of the same fold type. Only a small fraction of fold-fold combinations are observed in allosteric proteins, and homo-fold-fold combinations dominate. These analyses imply that the locations of allosteric sites including cryptic ones depend on protein topology. We further developed TopoAlloSite, a novel method that uses the kernel support vector machine to predict the location of allosteric sites on the overall protein topology based on the subgraph-matching kernel. TopoAlloSite successfully predicted known cryptic allosteric sites in several allosteric proteins like phosphopantothenoylcysteine synthetase, spermidine synthase, and sirtuin 6, demonstrating its power in identifying cryptic allosteric sites without performing long molecular dynamics simulations or large-scale experimental screening. Our study demonstrates that protein topology largely determines how its function can be allosterically regulated, which can be used to find new druggable targets and locate potential binding sites for rational allosteric drug design.
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Affiliation(s)
- Juan Xie
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Gaoxiang Pan
- BNLMS, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Yibo Li
- Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Luhua Lai
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
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6
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Martinez MZ, Olmo F, Taylor MC, Caudron F, Wilkinson SR. Dissecting the interstrand crosslink DNA repair system of Trypanosoma cruzi. DNA Repair (Amst) 2023; 125:103485. [PMID: 36989950 DOI: 10.1016/j.dnarep.2023.103485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 03/08/2023] [Accepted: 03/13/2023] [Indexed: 03/18/2023]
Abstract
DNA interstrand crosslinks (ICLs) are toxic lesions that can block essential biological processes. Here we show Trypanosoma cruzi, the causative agent of Chagas disease, is susceptible to ICL-inducing compounds including mechlorethamine and novel nitroreductase-activated prodrugs that have potential in treating this infection. To resolve such lesions, cells co-opt enzymes from "classical" DNA repair pathways that alongside dedicated factors operate in replication-dependent and -independent mechanisms. To assess ICL repair in T. cruzi, orthologues of SNM1, MRE11 and CSB were identified and their function assessed. The T. cruzi enzymes could complement the mechlorethamine susceptibility phenotype displayed by corresponding yeast and/or T. brucei null confirming their role as ICL repair factors while GFP-tagged TcSNM1, TcMRE11 and TcCSB were shown to localise to the nuclei of insect and/or intracellular form parasites. Gene disruption demonstrated that while each activity was non-essential for T. cruzi viability, nulls displayed a growth defect in at least one life cycle stage with TcMRE11-deficient trypomastigotes also compromised in mammalian cell infectivity. Phenotyping revealed all nulls were more susceptible to mechlorethamine than controls, a trait complemented by re-expression of the deleted gene. To assess interplay, the gene disruption approach was extended to generate T. cruzi deficient in TcSNM1/TcMRE11 or in TcSNM1/TcCSB. Analysis demonstrated these activities functioned across two ICL repair pathways with TcSNM1 and TcMRE11 postulated to operate in a replication-dependent system while TcCSB helps resolve transcription-blocking lesions. By unravelling how T. cruzi repairs ICL damage, specific inhibitors targeting repair components could be developed and used to increase the potency of trypanocidal ICL-inducing compounds.
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Affiliation(s)
- Monica Zavala Martinez
- School of Biological & Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Francisco Olmo
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Martin C Taylor
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Fabrice Caudron
- School of Biological & Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Shane R Wilkinson
- School of Biological & Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
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7
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Mitochondrial Spermidine Synthase is Essential for Blood-stage growth of the Malaria Parasite. Microbiol Res 2022; 265:127181. [PMID: 36162149 DOI: 10.1016/j.micres.2022.127181] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 08/14/2022] [Accepted: 08/28/2022] [Indexed: 11/21/2022]
Abstract
Positively-charged polyamines are essential molecules for the replication of eukaryotic cells and are particularly important for the rapid proliferation of parasitic protozoa and cancer cells. Unlike in Trypanosoma brucei, the inhibition of the synthesis of intermediate polyamine Putrescine caused only partial defect in malaria parasite blood-stage growth. In contrast, reducing the intracellular concentrations of Spermidine and Spermine by polyamine analogs caused significant defects in blood-stage growth in Plasmodium yoelii and P. falciparum. However, little is known about the synthesizing enzyme of Spermidine and Spermine in the malaria parasite. Herein, malaria parasite conserved Spermidine Synthase (SpdS) gene was targeted for deletion/complementation analyses by knockout/knock-in constructs in P. yoelii. SpdS was found to be essential for blood-stage growth. Live fluorescence imaging in blood-stages and sporozoites confirmed a specific mitochondrial localization, which is not known for any polyamine-synthesizing enzyme so far. This study identifies SpdS as an excellent drug targeting candidate against the malaria parasite, which is localized to the parasite mitochondrion.
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8
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Kwofie SK, Broni E, Dankwa B, Enninful KS, Kwarko GB, Darko L, Durvasula R, Kempaiah P, Rathi B, Miller Iii WA, Yaya A, Wilson MD. Outwitting an Old Neglected Nemesis: A Review on Leveraging Integrated Data-Driven Approaches to Aid in Unraveling of Leishmanicides of Therapeutic Potential. Curr Top Med Chem 2020; 20:349-366. [PMID: 31994465 DOI: 10.2174/1568026620666200128160454] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 08/20/2019] [Accepted: 09/12/2019] [Indexed: 11/22/2022]
Abstract
The global prevalence of leishmaniasis has increased with skyrocketed mortality in the past decade. The causative agent of leishmaniasis is Leishmania species, which infects populations in almost all the continents. Prevailing treatment regimens are consistently inefficient with reported side effects, toxicity and drug resistance. This review complements existing ones by discussing the current state of treatment options, therapeutic bottlenecks including chemoresistance and toxicity, as well as drug targets. It further highlights innovative applications of nanotherapeutics-based formulations, inhibitory potential of leishmanicides, anti-microbial peptides and organometallic compounds on leishmanial species. Moreover, it provides essential insights into recent machine learning-based models that have been used to predict novel leishmanicides and also discusses other new models that could be adopted to develop fast, efficient, robust and novel algorithms to aid in unraveling the next generation of anti-leishmanial drugs. A plethora of enriched functional genomic, proteomic, structural biology, high throughput bioassay and drug-related datasets are currently warehoused in both general and leishmania-specific databases. The warehoused datasets are essential inputs for training and testing algorithms to augment the prediction of biotherapeutic entities. In addition, we demonstrate how pharmacoinformatics techniques including ligand-, structure- and pharmacophore-based virtual screening approaches have been utilized to screen ligand libraries against both modeled and experimentally solved 3D structures of essential drug targets. In the era of data-driven decision-making, we believe that highlighting intricately linked topical issues relevant to leishmanial drug discovery offers a one-stop-shop opportunity to decipher critical literature with the potential to unlock implicit breakthroughs.
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Affiliation(s)
- Samuel K Kwofie
- Department of Biomedical Engineering, School of Engineering Sciences, College of Basic & Applied Sciences, University of Ghana, PMB LG 77, Legon, Accra, Ghana.,West African Center for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana.,Department of Medicine, Loyola University Chicago, Loyola University Medical Center, Maywood, IL 60153, United States
| | - Emmanuel Broni
- Department of Biomedical Engineering, School of Engineering Sciences, College of Basic & Applied Sciences, University of Ghana, PMB LG 77, Legon, Accra, Ghana
| | - Bismark Dankwa
- Department of Parasitology, Noguchi Memorial Institute for Medical Research (NMIMR), College of Health Sciences (CHS), University of Ghana, Legon, Accra, Ghana
| | - Kweku S Enninful
- Department of Parasitology, Noguchi Memorial Institute for Medical Research (NMIMR), College of Health Sciences (CHS), University of Ghana, Legon, Accra, Ghana
| | - Gabriel B Kwarko
- West African Center for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Louis Darko
- Department of Biomedical Engineering, School of Engineering Sciences, College of Basic & Applied Sciences, University of Ghana, PMB LG 77, Legon, Accra, Ghana
| | - Ravi Durvasula
- Department of Medicine, Loyola University Chicago, Loyola University Medical Center, Maywood, IL 60153, United States
| | - Prakasha Kempaiah
- Department of Medicine, Loyola University Chicago, Loyola University Medical Center, Maywood, IL 60153, United States
| | - Brijesh Rathi
- Department of Medicine, Loyola University Chicago, Loyola University Medical Center, Maywood, IL 60153, United States.,Department of Chemistry, Hansraj College University Enclave, University of Delhi, Delhi, 110007, India
| | - Whelton A Miller Iii
- Department of Medicine, Loyola University Chicago, Loyola University Medical Center, Maywood, IL 60153, United States.,Department of Chemistry, Physics, & Engineering, Lincoln University, Lincoln University, PA 19352, United States.,Department of Chemical and Biomolecular Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, 19104, United States
| | - Abu Yaya
- Department of Materials Science and Engineering, College of Basic & Applied Sciences, University of Ghana, Legon, Ghana
| | - Michael D Wilson
- Department of Medicine, Loyola University Chicago, Loyola University Medical Center, Maywood, IL 60153, United States.,Department of Parasitology, Noguchi Memorial Institute for Medical Research (NMIMR), College of Health Sciences (CHS), University of Ghana, Legon, Accra, Ghana
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9
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Talevi A, Carrillo C, Comini M. The Thiol-polyamine Metabolism of Trypanosoma cruzi: Molecular Targets and Drug Repurposing Strategies. Curr Med Chem 2019; 26:6614-6635. [PMID: 30259812 DOI: 10.2174/0929867325666180926151059] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 07/23/2018] [Accepted: 09/10/2018] [Indexed: 12/18/2022]
Abstract
Chagas´ disease continues to be a challenging and neglected public health problem in many American countries. The etiologic agent, Trypanosoma cruzi, develops intracellularly in the mammalian host, which hinders treatment efficacy. Progress in the knowledge of parasite biology and host-pathogen interaction has not been paralleled by the development of novel, safe and effective therapeutic options. It is then urgent to seek for novel therapeutic candidates and to implement drug discovery strategies that may accelerate the discovery process. The most appealing targets for pharmacological intervention are those essential for the pathogen and, whenever possible, absent or significantly different from the host homolog. The thiol-polyamine metabolism of T. cruzi offers interesting candidates for a rational design of selective drugs. In this respect, here we critically review the state of the art of the thiolpolyamine metabolism of T. cruzi and the pharmacological potential of its components. On the other hand, drug repurposing emerged as a valid strategy to identify new biological activities for drugs in clinical use, while significantly shortening the long time and high cost associated with de novo drug discovery approaches. Thus, we also discuss the different drug repurposing strategies available with a special emphasis in their applications to the identification of drug candidates targeting essential components of the thiol-polyamine metabolism of T. cruzi.
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Affiliation(s)
- Alan Talevi
- Medicinal Chemistry, Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata, La Plata, Argentina
| | - Carolina Carrillo
- Instituto de Ciencias y Tecnología Dr. César Milstein (ICT Milstein) - CONICET. Ciudad Autónoma de Buenos Aires, Argentina
| | - Marcelo Comini
- Institut Pasteur de Montevideo, Mataojo 2020, Montevideo 11400, Uruguay
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10
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Identification of small molecule enzyme inhibitors as broad-spectrum anthelmintics. Sci Rep 2019; 9:9085. [PMID: 31235822 PMCID: PMC6591293 DOI: 10.1038/s41598-019-45548-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 06/06/2019] [Indexed: 11/18/2022] Open
Abstract
Targeting chokepoint enzymes in metabolic pathways has led to new drugs for cancers, autoimmune disorders and infectious diseases. This is also a cornerstone approach for discovery and development of anthelmintics against nematode and flatworm parasites. Here, we performed omics-driven knowledge-based identification of chokepoint enzymes as anthelmintic targets. We prioritized 10 of 186 phylogenetically conserved chokepoint enzymes and undertook a target class repurposing approach to test and identify new small molecules with broad spectrum anthelmintic activity. First, we identified and tested 94 commercially available compounds using an in vitro phenotypic assay, and discovered 11 hits that inhibited nematode motility. Based on these findings, we performed chemogenomic screening and tested 32 additional compounds, identifying 6 more active hits. Overall, 6 intestinal (single-species), 5 potential pan-intestinal (whipworm and hookworm) and 6 pan-Phylum Nematoda (intestinal and filarial species) small molecule inhibitors were identified, including multiple azoles, Tadalafil and Torin-1. The active hit compounds targeted three different target classes in humans, which are involved in various pathways, including carbohydrate, amino acid and nucleotide metabolism. Last, using representative inhibitors from each target class, we demonstrated in vivo efficacy characterized by negative effects on parasite fecundity in hamsters infected with hookworms.
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11
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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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12
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Manta B, Bonilla M, Fiestas L, Sturlese M, Salinas G, Bellanda M, Comini MA. Polyamine-Based Thiols in Trypanosomatids: Evolution, Protein Structural Adaptations, and Biological Functions. Antioxid Redox Signal 2018; 28:463-486. [PMID: 29048199 DOI: 10.1089/ars.2017.7133] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
SIGNIFICANCE Major pathogenic enterobacteria and protozoan parasites from the phylum Euglenozoa, such as trypanosomatids, are endowed with glutathione (GSH)-spermidine (Sp) derivatives that play important roles in signaling and metal and thiol-redox homeostasis. For some Euglenozoa lineages, the GSH-Sp conjugates represent the main redox cosubstrates around which entire new redox systems have evolved. Several proteins underwent molecular adaptations to synthesize and utilize the new polyamine-based thiols. Recent Advances: The genomes of closely related organisms have recently been sequenced, which allows mining and analysis of gene sequences that belong to these peculiar redox systems. Similarly, the three-dimensional structures of several of these proteins have been solved, which allows for comparison with their counterparts in classical redox systems that rely on GSH/glutaredoxin and thioredoxin. CRITICAL ISSUES The evolutionary and structural aspects related to the emergence and use of GSH-Sp conjugates in Euglenozoa are reviewed focusing on unique structural specializations that proteins developed to use N1,N8-bisglutathionylspermidine (trypanothione) as redox cosubstrate. An updated overview on the biochemical and biological significance of the major enzymatic activities is also provided. FUTURE DIRECTIONS A thiol-redox system strictly dependent on trypanothione is a feature unique to trypanosomatids. The physicochemical properties of the polyamine-GSH conjugates were a major driving force for structural adaptation of proteins that use these thiols as ligand and redox cofactor. In fact, the structural differences of indispensable components of this system can be exploited toward selective drug development. Future research should clarify whether additional cellular processes are regulated by the trypanothione system. Antioxid. Redox Signal. 28, 463-486.
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Affiliation(s)
- Bruno Manta
- 1 Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo , Montevideo, Uruguay .,2 Laboratorio de Fisicoquímica Biológica, Instituto de Química Biológica , Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Mariana Bonilla
- 1 Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo , Montevideo, Uruguay .,2 Laboratorio de Fisicoquímica Biológica, Instituto de Química Biológica , Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Lucía Fiestas
- 1 Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo , Montevideo, Uruguay
| | - Mattia Sturlese
- 3 Department of Chemical Sciences, Università degli Studi di Padova , Padova, Italy
| | - Gustavo Salinas
- 4 Worm Biology Lab, Institut Pasteur de Montevideo , Montevideo, Uruguay .,5 Departamento de Biociencias, Facultad de Química, Universidad de la República , Montevideo, Uruguay
| | - Massimo Bellanda
- 3 Department of Chemical Sciences, Università degli Studi di Padova , Padova, Italy
| | - Marcelo A Comini
- 1 Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo , Montevideo, Uruguay
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13
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Yoshino R, Yasuo N, Hagiwara Y, Ishida T, Inaoka DK, Amano Y, Tateishi Y, Ohno K, Namatame I, Niimi T, Orita M, Kita K, Akiyama Y, Sekijima M. In silico, in vitro, X-ray crystallography, and integrated strategies for discovering spermidine synthase inhibitors for Chagas disease. Sci Rep 2017; 7:6666. [PMID: 28751689 PMCID: PMC5532286 DOI: 10.1038/s41598-017-06411-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 06/14/2017] [Indexed: 01/23/2023] Open
Abstract
Chagas disease results from infection by Trypanosoma cruzi and is a neglected tropical disease (NTD). Although some treatment drugs are available, their use is associated with severe problems, including adverse effects and limited effectiveness during the chronic disease phase. To develop a novel anti-Chagas drug, we virtually screened 4.8 million small molecules against spermidine synthase (SpdSyn) as the target protein using our super computer “TSUBAME2.5” and conducted in vitro enzyme assays to determine the half-maximal inhibitory concentration values. We identified four hit compounds that inhibit T. cruzi SpdSyn (TcSpdSyn) by in silico and in vitro screening. We also determined the TcSpdSyn–hit compound complex structure using X-ray crystallography, which shows that the hit compound binds to the putrescine-binding site and interacts with Asp171 through a salt bridge.
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Affiliation(s)
- Ryunosuke Yoshino
- Advanced Computational Drug Discovery Unit, Institute of Innovative Research, Tokyo Institute of Technology, 4259-J3-23, Nagatsuta-cho, Midori-ku, Yokohama, 226-8501, Japan.,Education Academy of Computational Life Sciences (ACLS), Tokyo Institute of Technology, Yokohama, 226-8501, Japan.,Global Scientific Information and Computing Center, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan.,Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8657, Japan.,Department of Computer Science, Graduate School of Information Science and Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8550, Japan
| | - Nobuaki Yasuo
- Education Academy of Computational Life Sciences (ACLS), Tokyo Institute of Technology, Yokohama, 226-8501, Japan.,Department of Computer Science, Graduate School of Information Science and Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8550, Japan
| | - Yohsuke Hagiwara
- Education Academy of Computational Life Sciences (ACLS), Tokyo Institute of Technology, Yokohama, 226-8501, Japan.,Medicinal Chemistry Research Labs, Drug Discovery Research, Astellas Pharma Inc, 21 Miyukigaoka, Tsukuba, Ibaraki, 305-8585, Japan
| | - Takashi Ishida
- Advanced Computational Drug Discovery Unit, Institute of Innovative Research, Tokyo Institute of Technology, 4259-J3-23, Nagatsuta-cho, Midori-ku, Yokohama, 226-8501, Japan.,Education Academy of Computational Life Sciences (ACLS), Tokyo Institute of Technology, Yokohama, 226-8501, Japan.,Department of Computer Science, Graduate School of Information Science and Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8550, Japan
| | - Daniel Ken Inaoka
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan.,School of Tropical Medicine and Global Health, Nagasaki University, Sakamoto, Nagasaki, 852-8523, Japan
| | - Yasushi Amano
- Medicinal Chemistry Research Labs, Drug Discovery Research, Astellas Pharma Inc, 21 Miyukigaoka, Tsukuba, Ibaraki, 305-8585, Japan
| | - Yukihiro Tateishi
- Medicinal Chemistry Research Labs, Drug Discovery Research, Astellas Pharma Inc, 21 Miyukigaoka, Tsukuba, Ibaraki, 305-8585, Japan
| | - Kazuki Ohno
- Education Academy of Computational Life Sciences (ACLS), Tokyo Institute of Technology, Yokohama, 226-8501, Japan.,Medicinal Chemistry Research Labs, Drug Discovery Research, Astellas Pharma Inc, 21 Miyukigaoka, Tsukuba, Ibaraki, 305-8585, Japan.,Catalyst Inc., Risona Kudan Building 5F KS Floor, 1-5-6 Kudan Minami, Chiyoda-ku, Tokyo, 102-0074, Japan
| | - Ichiji Namatame
- Medicinal Chemistry Research Labs, Drug Discovery Research, Astellas Pharma Inc, 21 Miyukigaoka, Tsukuba, Ibaraki, 305-8585, Japan
| | - Tatsuya Niimi
- Medicinal Chemistry Research Labs, Drug Discovery Research, Astellas Pharma Inc, 21 Miyukigaoka, Tsukuba, Ibaraki, 305-8585, Japan
| | - Masaya Orita
- Medicinal Chemistry Research Labs, Drug Discovery Research, Astellas Pharma Inc, 21 Miyukigaoka, Tsukuba, Ibaraki, 305-8585, Japan
| | - Kiyoshi Kita
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan.,School of Tropical Medicine and Global Health, Nagasaki University, Sakamoto, Nagasaki, 852-8523, Japan
| | - Yutaka Akiyama
- Advanced Computational Drug Discovery Unit, Institute of Innovative Research, Tokyo Institute of Technology, 4259-J3-23, Nagatsuta-cho, Midori-ku, Yokohama, 226-8501, Japan.,Education Academy of Computational Life Sciences (ACLS), Tokyo Institute of Technology, Yokohama, 226-8501, Japan.,Department of Computer Science, Graduate School of Information Science and Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8550, Japan
| | - Masakazu Sekijima
- Advanced Computational Drug Discovery Unit, Institute of Innovative Research, Tokyo Institute of Technology, 4259-J3-23, Nagatsuta-cho, Midori-ku, Yokohama, 226-8501, Japan. .,Education Academy of Computational Life Sciences (ACLS), Tokyo Institute of Technology, Yokohama, 226-8501, Japan. .,Global Scientific Information and Computing Center, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan. .,Department of Computer Science, Graduate School of Information Science and Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8550, Japan.
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14
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Macedo JP, Currier RB, Wirdnam C, Horn D, Alsford S, Rentsch D. Ornithine uptake and the modulation of drug sensitivity in Trypanosoma brucei. FASEB J 2017; 31:4649-4660. [PMID: 28679527 PMCID: PMC5602898 DOI: 10.1096/fj.201700311r] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 06/27/2017] [Indexed: 12/02/2022]
Abstract
Trypanosoma brucei, protozoan parasites that cause human African trypanosomiasis (HAT), depend on ornithine uptake and metabolism by ornithine decarboxylase (ODC) for survival. Indeed, ODC is the target of the WHO “essential medicine” eflornithine, which is antagonistic to another anti-HAT drug, suramin. Thus, ornithine uptake has important consequences in T. brucei, but the transporters have not been identified. We describe these amino acid transporters (AATs). In a heterologous expression system, TbAAT10-1 is selective for ornithine, whereas TbAAT2-4 transports both ornithine and histidine. These AATs are also necessary to maintain intracellular ornithine and polyamine levels in T. brucei, thereby decreasing sensitivity to eflornithine and increasing sensitivity to suramin. Consistent with competition for histidine, high extracellular concentrations of this amino acid phenocopied a TbAAT2-4 genetic defect. Our findings established TbAAT10-1 and TbAAT2-4 as the parasite ornithine transporters, one of which can be modulated by histidine, but both of which affect sensitivity to important anti-HAT drugs.—Macedo, J. P., Currier, R. B., Wirdnam, C., Horn, D., Alsford, S., Rentsch, D. Ornithine uptake and the modulation of drug sensitivity in Trypanosoma brucei.
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Affiliation(s)
- Juan P Macedo
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | - Rachel B Currier
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Corina Wirdnam
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | - David Horn
- Wellcome Trust Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Sam Alsford
- London School of Hygiene and Tropical Medicine, London, United Kingdom;
| | - Doris Rentsch
- Institute of Plant Sciences, University of Bern, Bern, Switzerland;
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15
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5-Substituted 3-chlorokenpaullone derivatives are potent inhibitors of Trypanosoma brucei bloodstream forms. Bioorg Med Chem 2016; 24:3790-800. [DOI: 10.1016/j.bmc.2016.06.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 06/09/2016] [Accepted: 06/11/2016] [Indexed: 01/31/2023]
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16
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Biosynthesis of polyamines and polyamine-containing molecules. Biochem J 2016; 473:2315-29. [DOI: 10.1042/bcj20160185] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 04/22/2016] [Indexed: 12/16/2022]
Abstract
Polyamines are evolutionarily ancient polycations derived from amino acids and are pervasive in all domains of life. They are essential for cell growth and proliferation in eukaryotes and are essential, important or dispensable for growth in bacteria. Polyamines present a useful scaffold to attach other moieties to, and are often incorporated into specialized metabolism. Life has evolved multiple pathways to synthesize polyamines, and structural variants of polyamines have evolved in bacteria, archaea and eukaryotes. Among the complex biosynthetic diversity, patterns of evolutionary reiteration can be distinguished, revealing evolutionary recycling of particular protein folds and enzyme chassis. The same enzyme activities have evolved from multiple protein folds, suggesting an inevitability of evolution of polyamine biosynthesis. This review discusses the different biosynthetic strategies used in life to produce diamines, triamines, tetra-amines and branched and long-chain polyamines. It also discusses the enzymes that incorporate polyamines into specialized metabolites and attempts to place polyamine biosynthesis in an evolutionary context.
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17
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Identification of Novel Chemical Scaffolds Inhibiting Trypanothione Synthetase from Pathogenic Trypanosomatids. PLoS Negl Trop Dis 2016; 10:e0004617. [PMID: 27070550 PMCID: PMC4829233 DOI: 10.1371/journal.pntd.0004617] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Accepted: 03/18/2016] [Indexed: 11/30/2022] Open
Abstract
Background The search for novel chemical entities targeting essential and parasite-specific pathways is considered a priority for neglected diseases such as trypanosomiasis and leishmaniasis. The thiol-dependent redox metabolism of trypanosomatids relies on bis-glutathionylspermidine [trypanothione, T(SH)2], a low molecular mass cosubstrate absent in the host. In pathogenic trypanosomatids, a single enzyme, trypanothione synthetase (TryS), catalyzes trypanothione biosynthesis, which is indispensable for parasite survival. Thus, TryS qualifies as an attractive drug target candidate. Methodology/Principal Finding A library composed of 144 compounds from 7 different families and several singletons was screened against TryS from three major pathogen species (Trypanosoma brucei, Trypanosoma cruzi and Leishmania infantum). The screening conditions were adjusted to the TryS´ kinetic parameters and intracellular concentration of substrates corresponding to each trypanosomatid species, and/or to avoid assay interference. The screening assay yielded suitable Z’ and signal to noise values (≥0.85 and ~3.5, respectively), and high intra-assay reproducibility. Several novel chemical scaffolds were identified as low μM and selective tri-tryp TryS inhibitors. Compounds displaying multi-TryS inhibition (N,N'-bis(3,4-substituted-benzyl) diamine derivatives) and an N5-substituted paullone (MOL2008) halted the proliferation of infective Trypanosoma brucei (EC50 in the nM range) and Leishmania infantum promastigotes (EC50 = 12 μM), respectively. A bis-benzyl diamine derivative and MOL2008 depleted intracellular trypanothione in treated parasites, which confirmed the on-target activity of these compounds. Conclusions/Significance Novel molecular scaffolds with on-target mode of action were identified as hit candidates for TryS inhibition. Due to the remarkable species-specificity exhibited by tri-tryp TryS towards the compounds, future optimization and screening campaigns should aim at designing and detecting, respectively, more potent and broad-range TryS inhibitors. Parasites from the genus Trypanosoma and Leishmania are etiologic agents for a group of neglected diseases with high morbidity and mortality rates in the developing world. Inasmuch as vaccine development is hampered by the successful mechanisms employed by the pathogens to evade the host immune response, chemotherapy remains as a safe option to fight these diseases. However, new drugs with better pharmacological performance (i.e. safety, efficacy and ease of administration) than those in current use are urgently needed. The thiol-redox metabolism of trypanosomatids offers an excellent opportunity for the development of more selective and efficacious medicines because it depends on a molecule, trypanothione (a bis-glutathionyl derivative of spermidine), unique and indispensable to the pathogens. Here we report the identification of novel inhibitors of trypanothione synthetase from three major trypanosomatid species of medical and veterinary relevance. Although highly conserved in sequence, trypanothione synthetases display significant species-specifity towards compounds, pointing to structural differences as determinants of ligand selectivity. Most of the active compounds presented two-digit μM inhibitory activity and serve as primary scaffolds to develop more potent inhibitors. Among them, N,N'-bis(benzyl)-substituted diamine and paullone derivatives are interesting candidates because of their potent and/or selective anti-trypanosomal and anti-trypanothione synthetase activity.
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18
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Alberca LN, Sbaraglini ML, Balcazar D, Fraccaroli L, Carrillo C, Medeiros A, Benitez D, Comini M, Talevi A. Discovery of novel polyamine analogs with anti-protozoal activity by computer guided drug repositioning. J Comput Aided Mol Des 2016; 30:305-21. [PMID: 26891837 DOI: 10.1007/s10822-016-9903-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 02/12/2016] [Indexed: 12/01/2022]
Abstract
Chagas disease is a parasitic infection caused by the protozoa Trypanosoma cruzi that affects about 6 million people in Latin America. Despite its sanitary importance, there are currently only two drugs available for treatment: benznidazole and nifurtimox, both exhibiting serious adverse effects and limited efficacy in the chronic stage of the disease. Polyamines are ubiquitous to all living organisms where they participate in multiple basic functions such as biosynthesis of nucleic acids and proteins, proliferation and cell differentiation. T. cruzi is auxotroph for polyamines, which are taken up from the extracellular medium by efficient transporters and, to a large extent, incorporated into trypanothione (bis-glutathionylspermidine), the major redox cosubstrate of trypanosomatids. From a 268-compound database containing polyamine analogs with and without inhibitory effect on T. cruzi we have inferred classificatory models that were later applied in a virtual screening campaign to identify anti-trypanosomal compounds among drugs already used for other therapeutic indications (i.e. computer-guided drug repositioning) compiled in the DrugBank and Sweetlead databases. Five of the candidates identified with this strategy were evaluated in cellular models from different pathogenic trypanosomatids (T. cruzi wt, T. cruzi PAT12, T. brucei and Leishmania infantum), and in vitro models of aminoacid/polyamine transport assays and trypanothione synthetase inhibition assay. Triclabendazole, sertaconazole and paroxetine displayed inhibitory effects on the proliferation of T. cruzi (epimastigotes) and the uptake of putrescine by the parasite. They also interfered with the uptake of others aminoacids and the proliferation of infective T. brucei and L. infantum (promastigotes). Trypanothione synthetase was ruled out as molecular target for the anti-parasitic activity of these compounds.
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Affiliation(s)
- Lucas N Alberca
- Laboratory of Bioactive Compounds Research and Development (LIDeB), Medicinal Chemistry, Department of Biological Science, Exact Sciences College, National University of La Plata (UNLP), Argentina, 47 & 115, B1900AJI, La Plata, Buenos Aires, Argentina
| | - María L Sbaraglini
- Laboratory of Bioactive Compounds Research and Development (LIDeB), Medicinal Chemistry, Department of Biological Science, Exact Sciences College, National University of La Plata (UNLP), Argentina, 47 & 115, B1900AJI, La Plata, Buenos Aires, Argentina
| | - Darío Balcazar
- Instituto de Ciencias y Tecnología Dr. César Milstein (ICT Milstein), Argentinean National Council of Scientific and Technical Research (CONICET), Buenos Aires, Argentina
| | - Laura Fraccaroli
- Instituto de Ciencias y Tecnología Dr. César Milstein (ICT Milstein), Argentinean National Council of Scientific and Technical Research (CONICET), Buenos Aires, Argentina
| | - Carolina Carrillo
- Instituto de Ciencias y Tecnología Dr. César Milstein (ICT Milstein), Argentinean National Council of Scientific and Technical Research (CONICET), Buenos Aires, Argentina
| | - Andrea Medeiros
- Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, 11400, Montevideo, Uruguay
| | - Diego Benitez
- Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, 11400, Montevideo, Uruguay
| | - Marcelo Comini
- Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, 11400, Montevideo, Uruguay
| | - Alan Talevi
- Laboratory of Bioactive Compounds Research and Development (LIDeB), Medicinal Chemistry, Department of Biological Science, Exact Sciences College, National University of La Plata (UNLP), Argentina, 47 & 115, B1900AJI, La Plata, Buenos Aires, Argentina.
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19
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Satpathy R, Konkimalla VB, Ratha J. In-silico gene co-expression network analysis in Paracoccidioides brasiliensis with reference to haloacid dehalogenase superfamily hydrolase gene. J Pharm Bioallied Sci 2015; 7:212-7. [PMID: 26229356 PMCID: PMC4517324 DOI: 10.4103/0975-7406.160023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 03/20/2015] [Accepted: 04/21/2015] [Indexed: 11/04/2022] Open
Abstract
CONTEXT Paracoccidioides brasiliensis, a dimorphic fungus is the causative agent of paracoccidioidomycosis, a disease globally affecting millions of people. The haloacid dehalogenase (HAD) superfamily hydrolases enzyme in the fungi, in particular, is known to be responsible in the pathogenesis by adhering to the tissue. Hence, identification of novel drug targets is essential. AIMS In-silico based identification of co-expressed genes along with HAD superfamily hydrolase in P. brasiliensis during the morphogenesis from mycelium to yeast to identify possible genes as drug targets. MATERIALS AND METHODS In total, four datasets were retrieved from the NCBI-gene expression omnibus (GEO) database, each containing 4340 genes, followed by gene filtration expression of the data set. Further co-expression (CE) study was performed individually and then a combination these genes were visualized in the Cytoscape 2. 8.3. STATISTICAL ANALYSIS USED Mean and standard deviation value of the HAD superfamily hydrolase gene was obtained from the expression data and this value was subsequently used for the CE calculation purpose by selecting specific correlation power and filtering threshold. RESULTS The 23 genes that were thus obtained are common with respect to the HAD superfamily hydrolase gene. A significant network was selected from the Cytoscape network visualization that contains total 7 genes out of which 5 genes, which do not have significant protein hits, obtained from gene annotation of the expressed sequence tags by BLAST X. For all the protein PSI-BLAST was performed against human genome to find the homology. CONCLUSIONS The gene co-expression network was obtained with respect to HAD superfamily dehalogenase gene in P. Brasiliensis.
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Affiliation(s)
- Raghunath Satpathy
- School of Life Science, Sambalpur University, Jyoti Vihar, Burla, Odisha, India
| | - V B Konkimalla
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar, Odisha, India
| | - Jagnyeswar Ratha
- School of Life Science, Sambalpur University, Jyoti Vihar, Burla, Odisha, India
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Sullivan JA, Tong JL, Wong M, Kumar A, Sarkar H, Ali S, Hussein I, Zaman I, Meredith EL, Helsby NA, Hu L, Wilkinson SR. Unravelling the role of SNM1 in the DNA repair system ofTrypanosoma brucei. Mol Microbiol 2015; 96:827-38. [DOI: 10.1111/mmi.12973] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2015] [Indexed: 12/31/2022]
Affiliation(s)
- James A. Sullivan
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
| | - Jie Lun Tong
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
| | - Martin Wong
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
| | - Ambika Kumar
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
| | - Hajrah Sarkar
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
| | - Sarah Ali
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
| | - Ikran Hussein
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
| | - Iqra Zaman
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
| | - Emma Louise Meredith
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
| | - Nuala A. Helsby
- Department of Molecular Medicine and Pathology; University of Auckland; Private Bag 92019 Auckland New Zealand
| | - Longqin Hu
- Department of Medicinal Chemistry; Ernest Mario School of Pharmacy; Rutgers; The State University of New Jersey; Piscataway NJ 08854 USA
| | - Shane R. Wilkinson
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
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21
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Maiwald F, Benítez D, Charquero D, Dar MA, Erdmann H, Preu L, Koch O, Hölscher C, Loaëc N, Meijer L, Comini MA, Kunick C. 9- and 11-Substituted 4-azapaullones are potent and selective inhibitors of African trypanosoma. Eur J Med Chem 2014; 83:274-83. [PMID: 24973661 DOI: 10.1016/j.ejmech.2014.06.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 06/04/2014] [Accepted: 06/10/2014] [Indexed: 10/25/2022]
Abstract
Trypanosomes from the "brucei" complex are pathogenic parasites endemic in sub-Saharan Africa and causative agents of severe diseases in humans and livestock. In order to identify new antitrypanosomal chemotypes against African trypanosomes, 4-azapaullones carrying α,β-unsaturated carbonyl chains in 9- or 11-position were synthesized employing a procedure with a Heck reaction as key step. Among the so prepared compounds, 5a and 5e proved to be potent antiparasitic agents with antitrypanosomal activity in the submicromolar range.
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Affiliation(s)
- Franziska Maiwald
- Technische Universität Braunschweig, Institut für Medizinische und Pharmazeutische Chemie, Beethovenstraße 55, D-38106 Braunschweig, Germany
| | - Diego Benítez
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400 Montevideo, Uruguay
| | - Diego Charquero
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400 Montevideo, Uruguay
| | - Mahin Abad Dar
- Forschungszentrum Borstel, Forschungsgruppe Infektionsimmunologie, Parkallee 22, D-23845 Borstel, Germany
| | - Hanna Erdmann
- Forschungszentrum Borstel, Forschungsgruppe Infektionsimmunologie, Parkallee 22, D-23845 Borstel, Germany
| | - Lutz Preu
- Technische Universität Braunschweig, Institut für Medizinische und Pharmazeutische Chemie, Beethovenstraße 55, D-38106 Braunschweig, Germany
| | - Oliver Koch
- Technische Universität Dortmund, Department of Chemistry and Chemical Biology, Technische Universität Dortmund, Otto-Hahn-Straße 6, 44227 Dortmund, Germany
| | - Christoph Hölscher
- Forschungszentrum Borstel, Forschungsgruppe Infektionsimmunologie, Parkallee 22, D-23845 Borstel, Germany
| | - Nadège Loaëc
- ManRos Therapeutics, Perharidy Research Center, 29680 Roscoff, France
| | - Laurent Meijer
- ManRos Therapeutics, Perharidy Research Center, 29680 Roscoff, France
| | - Marcelo A Comini
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400 Montevideo, Uruguay.
| | - Conrad Kunick
- Technische Universität Braunschweig, Institut für Medizinische und Pharmazeutische Chemie, Beethovenstraße 55, D-38106 Braunschweig, Germany.
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Leal SM, Amado DF, Kouznetsov VV, Escobar P. In vitro antileishmanial, trypanocidal, and Mammalian cell activities of diverse n,n' -dihetaryl substituted diamines and related compounds. Sci Pharm 2013; 81:43-55. [PMID: 23641328 PMCID: PMC3617668 DOI: 10.3797/scipharm.1205-14] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 10/14/2012] [Indexed: 12/30/2022] Open
Abstract
The leishmaniasis and Chagas diseases constitute a serious public health problem worldwide with few and ineffective treatment options. The search for new antiparasitic candidates at the initial steps of drug discovery and development is still necessary. The synthesis of 22 de novo synthetized N,N′-dihetaryl-alkyldiamine derivatives and in vitro antiparasitic activity were evaluated for the first time against intracellular and extracellular forms of Leishmania (Leishmania) infantum, L. (Viannia) panamensis, L. (Leishmania) amazonensis, and Trypanosoma cruzi. Additionally, the toxicity on mammalian cells was determined. Some of these substituted N,N′-diamines (25–35 % of the tested compounds) showed interesting results against free-living forms of parasites with activities at the inhibitory concentration (IC50) level of 1.96 to 28.83 μM for L. (L.) infantum promastigotes and IC50 of 0.02 to 5.31 μM for T. cruzi epimastigotes. No activity at the IC50 level on intracellular amastigotes of T. cruzi was observed. However, N1,N2-dibenzylethane-1,2-diamine 5a revealed an important activity against the intracellular amastigotes of L. infantum (IC50 25.42 μM ±0.33) and L. panamensis (IC50 58.20 μM ±3.23), while their analogue N1,N4-dibenzylbutane-1,4-diamine 5c resulted in activity only against L. panamensis (IC50 11.19 μM ±0.20) without toxicity on Vero and THP-1 mammalian cells. The active compounds against intracellular parasites with low toxicity in mammalian cells may be considered for future studies in experimental models.
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Affiliation(s)
- Sandra M Leal
- Centro de Investigación de Enfermedades Tropicales, CINTROP, Departamento de Ciencias Básicas, Escuela de Medicina, Universidad Industrial de Santander, Bucaramanga, Colombia
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Trypanothione: A unique bis-glutathionyl derivative in trypanosomatids. Biochim Biophys Acta Gen Subj 2013; 1830:3199-216. [DOI: 10.1016/j.bbagen.2013.01.013] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 01/11/2013] [Accepted: 01/16/2013] [Indexed: 11/21/2022]
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Gu X, Reid D, Higham DJ, Gilbert D. Mathematical modelling of polyamine metabolism in bloodstream-form Trypanosoma brucei: an application to drug target identification. PLoS One 2013; 8:e53734. [PMID: 23372667 PMCID: PMC3553166 DOI: 10.1371/journal.pone.0053734] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 12/04/2012] [Indexed: 11/23/2022] Open
Abstract
We present the first computational kinetic model of polyamine metabolism in bloodstream-form Trypanosoma brucei, the causative agent of human African trypanosomiasis. We systematically extracted the polyamine pathway from the complete metabolic network while still maintaining the predictive capability of the pathway. The kinetic model is constructed on the basis of information gleaned from the experimental biology literature and defined as a set of ordinary differential equations. We applied Michaelis-Menten kinetics featuring regulatory factors to describe enzymatic activities that are well defined. Uncharacterised enzyme kinetics were approximated and justified with available physiological properties of the system. Optimisation-based dynamic simulations were performed to train the model with experimental data and inconsistent predictions prompted an iterative procedure of model refinement. Good agreement between simulation results and measured data reported in various experimental conditions shows that the model has good applicability in spite of there being gaps in the required data. With this kinetic model, the relative importance of the individual pathway enzymes was assessed. We observed that, at low-to-moderate levels of inhibition, enzymes catalysing reactions of de novo AdoMet (MAT) and ornithine production (OrnPt) have more efficient inhibitory effect on total trypanothione content in comparison to other enzymes in the pathway. In our model, prozyme and TSHSyn (the production catalyst of total trypanothione) were also found to exhibit potent control on total trypanothione content but only when they were strongly inhibited. Different chemotherapeutic strategies against T. brucei were investigated using this model and interruption of polyamine synthesis via joint inhibition of MAT or OrnPt together with other polyamine enzymes was identified as an optimal therapeutic strategy.
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Affiliation(s)
- Xu Gu
- Medical Research Council Human Genetics Unit, Medical Research Council Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom.
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Abstract
SIGNIFICANCE Parasitic infections continue to be a major problem for global human health. Vaccines are practically not available and chemotherapy is highly unsatisfactory. One approach toward a novel antiparasitic drug development is to unravel pathways that may be suited as future targets. Parasitic organisms show a remarkable diversity with respect to the nature and functions of their main low-molecular-mass antioxidants and many of them developed pathways that do not have a counterpart in their mammalian hosts. RECENT ADVANCES Work of the last years disclosed the individual antioxidants employed by parasites and their distinct pathways. Entamoeba, Trichomonas, and Giardia directly use cysteine as main low-molecular-mass thiol but have divergent cysteine metabolisms. Malarial parasites rely exclusively on cysteine uptake and generate glutathione (GSH) as main free thiol as do metazoan parasites. Trypanosomes and Leishmania have a unique trypanothione-based thiol metabolism but employ individual mechanisms for their cysteine supply. In addition, some trypanosomatids synthesize ovothiol A and/or ascorbate. Various essential parasite enzymes such as trypanothione synthetase and trypanothione reductase in Trypanosomatids and the Schistosoma thioredoxin GSH reductase are currently intensively explored as drug target molecules. CRITICAL ISSUES Essentiality is a prerequisite but not a sufficient property of an enzyme to become a suited drug target. The availability of an appropriate in vivo screening system and many other factors are equally important. FUTURE DIRECTIONS The current organism-wide RNA-interference and proteome analyses are supposed to reveal many more interesting candidates for future drug development approaches directed against the parasite antioxidant defense systems.
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Grover A, Katiyar SP, Jeyakanthan J, Dubey VK, Sundar D. Mechanistic insights into the dual inhibition strategy for checking Leishmaniasis. J Biomol Struct Dyn 2012; 30:474-87. [DOI: 10.1080/07391102.2012.682212] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Abhinav Grover
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology (IIT) Delhi , Hauz Khas, New Delhi, 110016, India
| | - Shashank Prakash Katiyar
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology (IIT) Delhi , Hauz Khas, New Delhi, 110016, India
| | - Jeyaraman Jeyakanthan
- Department of Bioinformatics, Alagappa University , Karaikudi, Tamil Nadu, 630003, India
| | - Vikash Kumar Dubey
- Department of Biotechnology, Indian Institute of Technology (IIT) Guwahati , Guwahati, 781039, India
| | - Durai Sundar
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology (IIT) Delhi , Hauz Khas, New Delhi, 110016, India
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Grover A, Katiyar SP, Singh SK, Dubey VK, Sundar D. A leishmaniasis study: structure-based screening and molecular dynamics mechanistic analysis for discovering potent inhibitors of spermidine synthase. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1824:1476-83. [PMID: 22684087 DOI: 10.1016/j.bbapap.2012.05.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Revised: 05/18/2012] [Accepted: 05/31/2012] [Indexed: 11/16/2022]
Abstract
Protozoa Leishmania donovani (Ld) is the main cause of the endemic disease leishmaniasis. Spermidine synthase (SS), an important enzyme in the synthetic pathway of polyamines in Ld, is an essential element for the survival of this protozoan. Targeting SS may provide an important aid for the development of drugs against Ld. However, absence of tertiary structure of spermidine synthase of Leishmania donovani (LSS) limits the possibilities of structure based drug designing. Presence of the same enzyme in the host itself further challenges the drug development process. We modeled the tertiary structure of LSS using homology modeling approach making use of homologous X-ray crystallographic structure of spermidine synthase of Trypanosoma cruzi (TSS) (2.5Å resolution). The modeled structure was stabilized using Molecular Dynamics simulations. Based on active site structural differences between LSS and human spermidine synthase (HSS), we screened a large dataset of compounds against modeled protein using Glide virtual screen docking and selected two best inhibitors based on their docking scores (-10.04 and -13.11 respectively) with LSS and having least/no binding with the human enzyme. Finally Molecular Dynamics simulations were used to assess the dynamic stability of the ligand bound structures and to elaborate on the binding modes. This article is part of a Special Issue entitled: Computational Methods for Protein Interaction and Structural Prediction.
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Affiliation(s)
- Abhinav Grover
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology (IIT) Delhi, Hauz Khas, New Delhi 110016, India
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28
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Abstract
Parasitic diseases cause important losses in public and veterinary health worldwide. Novel drugs, more reliable diagnostic techniques and vaccine candidates are urgently needed. Due to the complexity of parasites and the intricate relationship with their hosts, development of successful tools to fight parasites has been very limited to date. The growing information on individual parasite genomes is now allowing the use of a broader range of potential strategies to gain deeper insights into the host-parasite relationship and has increased the possibilities to develop molecular-based tools in the field of parasitology. Nevertheless, functional studies of respective genes are still scarce. The RNA interference phenomenon resulting in the regulation of protein expression through the specific degradation of defined mRNAs, and more specifically the possibility of artificially induce it, has shown to be a powerful tool for the investigation of proteins function in many organisms. Recent advances in the design and delivery of targeting molecules allow efficient and highly specific gene silencing in different types of parasites, pointing out this technology as a powerful tool for the identification of novel vaccine candidates or drug targets at the high-throughput level in the near future, and could enable researchers to functionally annotate parasite genomes. The aim of this review is to provide a comprehensive overview on the current advances and pitfalls in gene silencing mechanisms, techniques, applications and prospects in animal parasites.
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29
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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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30
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Abstract
New drugs are urgently needed for the treatment of tropical and subtropical parasitic diseases, such as African sleeping sickness, Chagas' disease, leishmaniasis and malaria. Enzymes in polyamine biosynthesis and thiol metabolism, as well as polyamine transporters, are potential drug targets within these organisms. In the present review, the current knowledge of unique properties of polyamine metabolism in these parasites is outlined. These properties include prozyme regulation of AdoMetDC (S-adenosylmethionine decarboxylase) activity in trypanosomatids, co-expression of ODC (ornithine decarboxylase) and AdoMetDC activities in a single protein in plasmodia, and formation of trypanothione, a unique compound linking polyamine and thiol metabolism in trypanosomatids. Particularly interesting features within polyamine metabolism in these parasites are highlighted for their potential in selective therapeutic strategies.
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31
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Brun R, Don R, Jacobs RT, Wang MZ, Barrett MP. Development of novel drugs for human African trypanosomiasis. Future Microbiol 2011; 6:677-91. [DOI: 10.2217/fmb.11.44] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Human African trypanosomiasis (HAT) or ‘sleeping sickness’ is a neglected tropical disease caused by the parasite Trypanosoma brucei. Novel models for funding pharmaceutical development against HAT are beginning to yield results. The Drugs for Neglected Diseases initiative (DNDi) rediscovered a nitroimidazole, fexinidazole, which is currently in Phase I clinical trials. Novel benzoxaboroles, discovered by Anacor, Scynexis and DNDi, have good pharmacokinetic properties in plasma and in the brain and are curative in a murine model of stage two HAT with brain infection. The Consortium for Parasitic Drug Development (CPDD) has identified a series of dicationic compounds that can cure a monkey model of stage two HAT. With other screening programs yielding hits, the pipeline for new HAT drugs might finally begin to fill.
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Affiliation(s)
- Reto Brun
- Department Medical Parasitology & Infection Biology, Swiss Tropical & Public Health Institute, and, University of Basel, CH-4002 Basel, Switzerland
| | - Robert Don
- Drugs for Neglected Diseases initiative, Geneva, Switzerland
| | - Robert T Jacobs
- Department of Chemistry, SCYNEXIS, Inc., PO Box 12878, Research Triangle Park, NC, 27709-2878, USA
| | - Michael Zhuo Wang
- Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Michael P Barrett
- Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, Scotland
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32
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Wyatt PG, Gilbert IH, Read KD, Fairlamb AH. Target validation: linking target and chemical properties to desired product profile. Curr Top Med Chem 2011; 11:1275-83. [PMID: 21401506 PMCID: PMC3182078 DOI: 10.2174/156802611795429185] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2010] [Accepted: 11/25/2010] [Indexed: 01/21/2023]
Abstract
The discovery of drugs is a lengthy, high-risk and expensive business taking at least 12 years and is estimated to cost upwards of US$800 million for each drug to be successfully approved for clinical use. Much of this cost is driven by the late phase clinical trials and therefore the ability to terminate early those projects destined to fail is paramount to prevent unwanted costs and wasted effort. Although neglected diseases drug discovery is driven more by unmet medical need rather than financial considerations, the need to minimise wasted money and resources is even more vital in this under-funded area. To ensure any drug discovery project is addressing the requirements of the patients and health care providers and delivering a benefit over existing therapies, the ideal attributes of a novel drug needs to be pre-defined by a set of criteria called a target product profile. Using a target product profile the drug discovery process, clinical study design, and compound characteristics can be defined all the way back through to the suitability or druggability of the intended biochemical target. Assessment and prioritisation of the most promising targets for entry into screening programmes is crucial for maximising chances of success.
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Affiliation(s)
| | | | | | - Alan H Fairlamb
- Address correspondence to this author at the Drug Discovery Unit, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK; Tel: (44)1382 385155; Fax: (44)1382 385542; E-mail:
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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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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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Cross-species activation of trypanosome S-adenosylmethionine decarboxylase by the regulatory subunit prozyme. Mol Biochem Parasitol 2009; 168:1-6. [PMID: 19523496 DOI: 10.1016/j.molbiopara.2009.05.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2009] [Revised: 05/22/2009] [Accepted: 05/30/2009] [Indexed: 11/21/2022]
Abstract
The protozoan parasite Trypanosoma cruzi is the causative agent of Chagas disease (American trypanosomiasis), a neglected disease of Central and South America. Polyamines are small organic cations that are required for cell growth and their biosynthesis has been the target of drug discovery efforts in both T. cruzi and the related Trypanosoma brucei parasites. Here we show that, as previously demonstrated for T. brucei, S-adenosylmethionine decarboxylase (AdoMetDC) from T. cruzi forms a heterodimer with prozyme, an inactive homolog that arose by gene duplication of the canonical enzyme uniquely in the trypanosomatids. The T. cruzi AdoMetDC/prozyme heterodimer is 110-fold more active than homodimeric AdoMetDC. Unlike for T. brucei AdoMetDC, the activity of the T. cruzi heterodimer is further stimulated by putrescine to generate an enzyme with similar catalytic efficiency to the fully activated T. brucei enzyme. The effects of prozyme on T. cruzi AdoMetDC are mediated by an increase in k(cat), while the predominant effect of putrescine is to lower the K(m). Finally we demonstrate that the cross-species heterodimers of T. cruzi and T. brucei AdoMetDC and prozyme pairs are functional, and that putrescine is required for prozyme to fully activate the mixed species heterodimers. These data demonstrate that prozyme mediated activation of AdoMetDC is a common mechanism required to regulate AdoMetDC activity in the trypanosomatids.
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36
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Vaidyanathan R, Kodukula K. Using a systems biology approach to dissect parasite-host interactions. Drug Dev Res 2009. [DOI: 10.1002/ddr.20307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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RNA interference-mediated silencing of ornithine decarboxylase and spermidine synthase genes in Trypanosoma brucei provides insight into regulation of polyamine biosynthesis. EUKARYOTIC CELL 2009; 8:747-55. [PMID: 19304951 DOI: 10.1128/ec.00047-09] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Polyamine biosynthesis is a drug target for the treatment of African sleeping sickness; however, mechanisms regulating the pathway in Trypanosoma brucei are not well understood. Recently, we showed that RNA interference (RNAi)-mediated gene silencing or the inhibition of S-adenosylmethionine decarboxylase (AdoMetDC) led to the upregulation of the AdoMetDC activator, prozyme, and ornithine decarboxylase (ODC) proteins. To determine if this regulatory response is specific to AdoMetDC, we studied the effects of the RNAi-induced silencing of the spermidine synthase (SpdSyn) and ODC genes in bloodstream form T. brucei. The knockdown of either gene product led to the depletion of the polyamine and trypanothione pools and to cell death. Decarboxylated AdoMet levels were elevated, while AdoMet was not affected. There was no significant effect on the protein levels of other polyamine pathway enzymes. The treatment of parasites with the ODC inhibitor alpha-difluoromethylornithine gave similar results to those observed for ODC knockdown. Thus, the cellular response to the loss of AdoMetDC activity is distinctive, suggesting that AdoMetDC activity controls the expression levels of the other spermidine biosynthetic enzymes. RNAi-mediated cell death occurred more rapidly for ODC than for SpdSyn. Further, the ODC RNAi cells were rescued by putrescine, but not spermidine, suggesting that the depletion of both putrescine and spermidine is more detrimental than the depletion of spermidine alone. This finding may contribute to the effectiveness of ODC as a target for the treatment of African sleeping sickness, thus providing important insight into the mechanism of action of a key antitrypanosomal agent.
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38
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Willert EK, Phillips MA. Regulated expression of an essential allosteric activator of polyamine biosynthesis in African trypanosomes. PLoS Pathog 2008; 4:e1000183. [PMID: 18949025 PMCID: PMC2562514 DOI: 10.1371/journal.ppat.1000183] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Accepted: 09/23/2008] [Indexed: 12/11/2022] Open
Abstract
Trypanosoma brucei is the causative agent of African sleeping sickness. The polyamine biosynthetic pathway has the distinction of being the target of the only clinically proven anti-trypanosomal drug with a known mechanism of action. Polyamines are essential for cell growth, and their metabolism is extensively regulated. However, trypanosomatids appear to lack the regulatory control mechanisms described in other eukaryotic cells. In T. brucei, S-adenosylmethionine decarboxylase (AdoMetDC) and ornithine decarboxylase (ODC) are required for the synthesis of polyamines and also for the unique redox-cofactor trypanothione. Further, trypanosomatid AdoMetDC is activated by heterodimer formation with a catalytically dead homolog termed prozyme, found only in these species. To study polyamine regulation in T. brucei, we generated inducible AdoMetDC RNAi and prozyme conditional knockouts in the mammalian blood form stage. Depletion of either protein led to a reduction in spermidine and trypanothione and to parasite death, demonstrating that prozyme activation of AdoMetDC is essential. Under typical growth conditions, prozyme concentration is limiting in comparison to AdoMetDC. However, both prozyme and ODC protein levels were significantly increased relative to stable transcript levels by knockdown of AdoMetDC or its chemical inhibition. Changes in protein stability do not appear to account for the increased steady-state protein levels, as both enzymes are stable in the presence of cycloheximide. These observations suggest that prozyme and ODC are translationally regulated in response to perturbations in the pathway. In conclusion, we describe the first evidence for regulation of polyamine biosynthesis in T. brucei and we demonstrate that the unique regulatory subunit of AdoMetDC is a key component of this regulation. The data support ODC and AdoMetDC as the key control points in the pathway and the likely rate-limiting steps in polyamine biosynthesis.
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Affiliation(s)
- Erin K. Willert
- Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
| | - Margaret A. Phillips
- Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
- * E-mail:
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Irigoín F, Cibils L, Comini MA, Wilkinson SR, Flohé L, Radi R. Insights into the redox biology of Trypanosoma cruzi: Trypanothione metabolism and oxidant detoxification. Free Radic Biol Med 2008; 45:733-42. [PMID: 18588970 DOI: 10.1016/j.freeradbiomed.2008.05.028] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Revised: 05/24/2008] [Accepted: 05/28/2008] [Indexed: 10/22/2022]
Abstract
Trypanosoma cruzi is the etiologic agent of Chagas' disease, an infection that affects several million people in Latin America. With no immediate prospect of a vaccine and problems associated with current chemotherapies, the development of new treatments is an urgent priority. Several aspects of the redox metabolism of this parasite differ enough from those in the mammalian host to be considered targets for drug development. Here, we review the information about a trypanosomatid-specific molecule centrally involved in redox metabolism, the dithiol trypanothione, and the main effectors of cellular antioxidant defense. We focus mainly on data from T. cruzi, making comparisons with other trypanosomatids whenever possible. In these parasites trypanothione participates in crucial thiol-disulfide exchange reactions and serves as electron donor in different metabolic pathways, from synthesis of DNA precursors to oxidant detoxification. Interestingly, the levels of several enzymes involved in trypanothione metabolism and oxidant detoxification increase during the transformation of T. cruzi to its mammalian-infective form and the overexpression of some of them has been associated with increased resistance to macrophage-dependent oxidative killing. Together, the evidence suggests a central role of the trypanothione-dependent antioxidant systems in the infection process.
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Affiliation(s)
- Florencia Irigoín
- Departmento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Uruguay
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40
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Krauth-Siegel RL, Comini MA. Redox control in trypanosomatids, parasitic protozoa with trypanothione-based thiol metabolism. Biochim Biophys Acta Gen Subj 2008; 1780:1236-48. [PMID: 18395526 DOI: 10.1016/j.bbagen.2008.03.006] [Citation(s) in RCA: 294] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Revised: 02/26/2008] [Accepted: 03/11/2008] [Indexed: 01/09/2023]
Abstract
Trypanosomes and leishmania, the causative agents of several tropical diseases, possess a unique redox metabolism which is based on trypanothione. The bis(glutathionyl)spermidine is the central thiol that delivers electrons for the synthesis of DNA precursors, the detoxification of hydroperoxides and other trypanothione-dependent pathways. Many of the reactions are mediated by tryparedoxin, a distant member of the thioredoxin protein family. Trypanothione is kept reduced by the parasite-specific flavoenzyme trypanothione reductase. Since glutathione reductases and thioredoxin reductases are missing, the reaction catalyzed by trypanothione reductase represents the only connection between the NADPH- and the thiol-based redox metabolisms. Thus, cellular thiol redox homeostasis is maintained by the biosynthesis and reduction of trypanothione. Nearly all proteins of the parasite-specific trypanothione metabolism have proved to be essential.
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