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Cabello-Donayre M, Cabello-Donayre I, Guerra D, Orrego LM, Morales JC, Cautain B, Vicente F, Pérez-Victoria JM. A yeast-based high-throughput screen identifies inhibitors of trypanosomatid HRG heme transporters with potent leishmanicidal and trypanocidal activity. Int J Antimicrob Agents 2024; 63:107092. [PMID: 38242251 DOI: 10.1016/j.ijantimicag.2024.107092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 12/19/2023] [Accepted: 01/11/2024] [Indexed: 01/21/2024]
Abstract
OBJECTIVES New drugs are required to treat neglected diseases caused by trypanosomatid parasites such as Leishmania, Trypanosoma brucei and Trypanosoma cruzi. An Achilles' heel of these parasites is their heme auxotrophy; they have an absolute dependence on scavenging this molecule from the host, and trypanosomatid HRG heme transporters (TrypHRG) play an important role in this process. As these proteins are essential for the parasites and have low similarity with their human orthologue, they have been proposed as attractive therapeutic targets. Here, we have developed two yeast-based assays that allow an inexpensive high-throughput screening of TrypHRG inhibitors within a cellular context. METHODS We first assessed that Leishmania major, Leishmania donovani and T. brucei HRG proteins were heterologously expressed in the digestive vacuole membrane of a mutant heme auxotrophic yeast strain. Here, TrypHRG imports hemoglobinderived heme into the cytosol, allowing mutant yeast to grow in the presence of low hemoglobin concentrations and promoting the activity of hemeproteins such as catalase, which was used as a reporter of cytosolic heme levels. RESULTS In the presence of a TrypHRG inhibitor, both catalase activity (test 1) and yeast growth (test 2) were diminished, being easily monitored. The assays were then tested on a pilot scale for HTS purposes using a collection of repurposing drugs and food antioxidants. Some of the TrypHRG inhibitors identified in yeast presented strong trypanocidal and leishmanicidal activity in the submicromolar range, proving the potential of this approach. CONCLUSIONS Cumulatively, it was shown that the inhibition bioassays developed were robust and applicable to large-scale HTS.
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Affiliation(s)
- María Cabello-Donayre
- Instituto de Parasitología y Biomedicina "López-Neyra", CSIC, (IPBLN-CSIC), PTS Granada, Granada, Spain; Universidad Internacional de La Rioja, Logroño, La Rioja, Spain
| | - Irene Cabello-Donayre
- Instituto de Parasitología y Biomedicina "López-Neyra", CSIC, (IPBLN-CSIC), PTS Granada, Granada, Spain
| | - Diego Guerra
- Instituto de Parasitología y Biomedicina "López-Neyra", CSIC, (IPBLN-CSIC), PTS Granada, Granada, Spain; Programa de Estudio y Control de Enfermedades Tropicales PECET, Faculty of Medicine, University of Antioquia, Medellín, Colombia
| | - Lina M Orrego
- Instituto de Parasitología y Biomedicina "López-Neyra", CSIC, (IPBLN-CSIC), PTS Granada, Granada, Spain
| | - Juan C Morales
- Instituto de Parasitología y Biomedicina "López-Neyra", CSIC, (IPBLN-CSIC), PTS Granada, Granada, Spain
| | - Bastien Cautain
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, PTS Granada, Granada, Spain
| | - Francisca Vicente
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, PTS Granada, Granada, Spain
| | - José M Pérez-Victoria
- Instituto de Parasitología y Biomedicina "López-Neyra", CSIC, (IPBLN-CSIC), PTS Granada, Granada, Spain.
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Nascimento IJDS, Cavalcanti MDAT, de Moura RO. Exploring N-myristoyltransferase as a promising drug target against parasitic neglected tropical diseases. Eur J Med Chem 2023; 258:115550. [PMID: 37336067 DOI: 10.1016/j.ejmech.2023.115550] [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: 05/15/2023] [Revised: 06/04/2023] [Accepted: 06/06/2023] [Indexed: 06/21/2023]
Abstract
Neglected tropical diseases (NTDs) constitute a group of approximately 20 infectious diseases that mainly affect the impoverished population without basic sanitation in tropical countries. These diseases are responsible for many deaths worldwide, costing billions of dollars in public health investment to treat and control these infections. Among them are the diseases caused by protozoa of the Trypanosomatid family, which constitute Trypanosoma cruzi (Chagas disease), Trypanosoma brucei (sleeping sickness), and Leishmaniasis. In addition, there is a classification of other diseases, called the big three, AIDS, tuberculosis, and malaria, which are endemic in countries with tropical conditions. Despite the high mortality rates, there is still a gap in the treatment. The drugs have a high incidence of side effects and protozoan resistance, justifying the investment in developing new alternatives. In fact, the Target-Based Drug Design (TBDD) approach is responsible for identifying several promising compounds, and among the targets explored through this approach, N-myristoyltransferase (NMT) stands out. It is an enzyme related to the co-translational myristoylation of N-terminal glycine in various peptides. The myristoylation process is a co-translation that occurs after removing the initiator methionine. This process regulates the assembly of protein complexes and stability, which justifies its potential as a drug target. In order to propose NMT as a potential target for parasitic diseases, this review will address the entire structure and function of this enzyme and the primary studies demonstrating its promising potential against Leishmaniasis, T. cruzi, T. brucei, and malaria. We hope our information can help researchers worldwide search for potential drugs against these diseases that have been threatening the health of the world's population.
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Affiliation(s)
- Igor José Dos Santos Nascimento
- Postgraduate Program in Pharmaceutical Sciences, State University of Paraíba, Campina Grande, 58429-500, Brazil; Cesmac University Center, Pharmacy Departament, Maceió, Brazil; Drug Development and Synthesis Laboratory, Department of Pharmacy, State University of Paraíba, Campina Grande, 58429-500, Brazil.
| | - Misael de Azevedo Teotônio Cavalcanti
- Postgraduate Program in Pharmaceutical Sciences, State University of Paraíba, Campina Grande, 58429-500, Brazil; Drug Development and Synthesis Laboratory, Department of Pharmacy, State University of Paraíba, Campina Grande, 58429-500, Brazil
| | - Ricardo Olimpio de Moura
- Postgraduate Program in Pharmaceutical Sciences, State University of Paraíba, Campina Grande, 58429-500, Brazil; Drug Development and Synthesis Laboratory, Department of Pharmacy, State University of Paraíba, Campina Grande, 58429-500, Brazil
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Groszmann M, De Rosa A, Chen W, Qiu J, McGaughey SA, Byrt CS, Evans JR. A high-throughput yeast approach to characterize aquaporin permeabilities: Profiling the Arabidopsis PIP aquaporin sub-family. FRONTIERS IN PLANT SCIENCE 2023; 14:1078220. [PMID: 36760647 PMCID: PMC9907170 DOI: 10.3389/fpls.2023.1078220] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 01/04/2023] [Indexed: 06/18/2023]
Abstract
INTRODUCTION Engineering membrane transporters to achieve desired functionality is reliant on availability of experimental data informing structure-function relationships and intelligent design. Plant aquaporin (AQP) isoforms are capable of transporting diverse substrates such as signaling molecules, nutrients, metalloids, and gases, as well as water. AQPs can act as multifunctional channels and their transport function is reliant on many factors, with few studies having assessed transport function of specific isoforms for multiple substrates. METHODS High-throughput yeast assays were developed to screen for transport function of plant AQPs, providing a platform for fast data generation and cataloguing of substrate transport profiles. We applied our high-throughput growth-based yeast assays to screen all 13 Arabidopsis PIPs (AtPIPs) for transport of water and several neutral solutes: hydrogen peroxide (H2O2), boric acid (BA), and urea. Sodium (Na+) transport was assessed using elemental analysis techniques. RESULTS All AtPIPs facilitated water and H2O2 transport, although their growth phenotypes varied, and none were candidates for urea transport. For BA and Na+ transport, AtPIP2;2 and AtPIP2;7 were the top candidates, with yeast expressing these isoforms having the most pronounced toxicity response to BA exposure and accumulating the highest amounts of Na+. Linking putative AtPIP isoform substrate transport profiles with phylogenetics and gene expression data, enabled us to align possible substrate preferences with known and hypothesized biological roles of AtPIPs. DISCUSSION This testing framework enables efficient cataloguing of putative transport functionality of diverse AQPs at a scale that can help accelerate our understanding of AQP biology through big data approaches (e.g. association studies). The principles of the individual assays could be further adapted to test additional substrates. Data generated from this framework could inform future testing of AQP physiological roles, and address knowledge gaps in structure-function relationships to improve engineering efforts.
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Affiliation(s)
- Michael Groszmann
- Australian Research Council (ARC) Centre of Excellence for Translational Photosynthesis, Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Annamaria De Rosa
- Australian Research Council (ARC) Centre of Excellence for Translational Photosynthesis, Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Weihua Chen
- Australian Research Council (ARC) Centre of Excellence for Translational Photosynthesis, Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Jiaen Qiu
- Australian Research Council (ARC) Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, SA, Australia
| | - Samantha A. McGaughey
- Australian Research Council (ARC) Centre of Excellence for Translational Photosynthesis, Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Caitlin S. Byrt
- Australian Research Council (ARC) Centre of Excellence for Translational Photosynthesis, Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - John R. Evans
- Australian Research Council (ARC) Centre of Excellence for Translational Photosynthesis, Research School of Biology, Australian National University, Canberra, ACT, Australia
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Alpizar-Sosa EA, Kumordzi Y, Wei W, Whitfield PD, Barrett MP, Denny PW. Genome deletions to overcome the directed loss of gene function in Leishmania. Front Cell Infect Microbiol 2022; 12:988688. [PMID: 36211960 PMCID: PMC9539739 DOI: 10.3389/fcimb.2022.988688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 09/06/2022] [Indexed: 11/13/2022] Open
Abstract
With the global reach of the Neglected Tropical Disease leishmaniasis increasing, coupled with a tiny armory of therapeutics which all have problems with resistance, cost, toxicity and/or administration, the validation of new drug targets in the causative insect vector borne protozoa Leishmania spp is more important than ever. Before the introduction of CRISPR Cas9 technology in 2015 genetic validation of new targets was carried out largely by targeted gene knockout through homologous recombination, with the majority of genes targeted (~70%) deemed non-essential. In this study we exploit the ready availability of whole genome sequencing technology to reanalyze one of these historic cell lines, a L. major knockout in the catalytic subunit of serine palmitoyltransferase (LCB2), which causes a complete loss of sphingolipid biosynthesis but remains viable and infective. This revealed a number of Single Nucleotide Polymorphisms, but also the complete loss of several coding regions including a gene encoding a putative ABC3A orthologue, a putative sterol transporter. Hypothesizing that the loss of such a transporter may have facilitated the directed knockout of the catalytic subunit of LCB2 and the complete loss of de novo sphingolipid biosynthesis, we re-examined LCB2 in a L. mexicana line engineered for straightforward CRISPR Cas9 directed manipulation. Strikingly, LCB2 could not be knocked out indicating essentiality. However, simultaneous deletion of LCB2 and the putative ABC3A was possible. This indicated that the loss of the putative ABC3A facilitated the loss of sphingolipid biosynthesis in Leishmania, and suggested that we should re-examine the many other Leishmania knockout lines where genes were deemed non-essential.
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Affiliation(s)
| | - Yasmine Kumordzi
- Department of Biosciences, Durham University, Durham, United Kingdom
| | - Wenbin Wei
- Department of Biosciences, Durham University, Durham, United Kingdom
| | - Phillip D. Whitfield
- Glasgow Polyomics, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Michael P. Barrett
- Glasgow Polyomics, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom,Wellcome Centre for Integrative Parasitology, School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Paul W. Denny
- Department of Biosciences, Durham University, Durham, United Kingdom,*Correspondence: Paul W. Denny,
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Hoffman CS. Use of a Fission Yeast Platform to Identify and Characterize Small Molecule PDE Inhibitors. Front Pharmacol 2022; 12:833156. [PMID: 35111072 PMCID: PMC8802716 DOI: 10.3389/fphar.2021.833156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 12/23/2021] [Indexed: 11/13/2022] Open
Abstract
Cyclic nucleotide phosphodiesterases (PDEs) have been proven to be targets for which highly selective and potent drugs can be developed. Mammalian genomes possess 21 genes whose products are pharmacologically grouped into 11 families; however related genes from pathogenic organisms display sufficient divergence from the mammalian homologs such that PDE inhibitors to these enzymes could be used to treat parasitic infections without acting on the related human PDEs. We have developed a platform for expressing cloned PDEs in the fission yeast Schizosaccharomyces pombe, allowing for inexpensive, but robust screening for small molecule inhibitors that are cell permeable. Such compounds typically display the expected biological activity when tested in cell culture, including anti-inflammatory properties for PDE4 and PDE7 inhibitors. The genetic pliability of S. pombe also allows for molecular genetic screens to identify mutations in target PDE genes that confer some resistance to these inhibitors as a way of investigating the PDE-inhibitor interaction. This screening method is readily accessible to academic laboratories as it does not require the purification of large quantities of a target protein. This allows for the discovery and profiling of PDE inhibitors to treat inflammation or of inhibitors of targets such as pathogen PDEs for which there may not be a sufficient financial motivation for pharmaceutical companies to identify selective PDE inhibitors using more traditional in vitro enzyme-based screening methods.
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Affiliation(s)
- Charles S Hoffman
- Biology Department, Boston College, Chestnut Hill, MA, United States
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Escrivani DO, Charlton RL, Caruso MB, Burle-Caldas GA, Borsodi MPG, Zingali RB, Arruda-Costa N, Palmeira-Mello MV, de Jesus JB, Souza AMT, Abrahim-Vieira B, Freitag-Pohl S, Pohl E, Denny PW, Rossi-Bergmann B, Steel PG. Chalcones identify cTXNPx as a potential antileishmanial drug target. PLoS Negl Trop Dis 2021; 15:e0009951. [PMID: 34780470 PMCID: PMC8664226 DOI: 10.1371/journal.pntd.0009951] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 12/10/2021] [Accepted: 10/26/2021] [Indexed: 12/31/2022] Open
Abstract
With current drug treatments failing due to toxicity, low efficacy and resistance; leishmaniasis is a major global health challenge that desperately needs new validated drug targets. Inspired by activity of the natural chalcone 2’,6’-dihydroxy-4’-methoxychalcone (DMC), the nitro-analogue, 3-nitro-2’,4’,6’- trimethoxychalcone (NAT22, 1c) was identified as potent broad spectrum antileishmanial drug lead. Structural modification provided an alkyne containing chemical probe that labelled a protein within the parasite that was confirmed as cytosolic tryparedoxin peroxidase (cTXNPx). Crucially, labelling is observed in both promastigote and intramacrophage amastigote life forms, with no evidence of host macrophage toxicity. Incubation of the chalcone in the parasite leads to ROS accumulation and parasite death. Deletion of cTXNPx, by CRISPR-Cas9, dramatically impacts upon the parasite phenotype and reduces the antileishmanial activity of the chalcone analogue. Molecular docking studies with a homology model of in-silico cTXNPx suggest that the chalcone is able to bind in the putative active site hindering access to the crucial cysteine residue. Collectively, this work identifies cTXNPx as an important target for antileishmanial chalcones. Leishmaniasis is an insect vector-borne parasitic disease. With >350 million people world wide considered at risk, 12 million people currently infected and an economic cost that can be estimated in terms of >3.3 million working life years lost, leishmaniasis is a major global health challenge. The disease is of particular importance in Brazil. Current treatment of leishmaniasis is difficult requiring a long, costly course of drug treatment using old drugs with poor safety indications requiring close medical supervision. Moreover, resistance to current antileishmanials is growing, emphasising a major need for new drug targets. In earlier work we had identified a naturally inspired chalcone which had promising antileishmanial activity but with no known mode of action. In this work we use an analogue of this molecule as an activity based probe to identify a protein target of the chalcone. This protein, cTXNPx, has a major role in protecting the parasite against attack by reactive oxygen species in the host cell. By inhibiting this protein the parasite can no longer survive in the host. Collectively this work validates cTXNPx as a drug target with the chalcone as a lead structure for future drug discovery programmes.
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Affiliation(s)
- Douglas O. Escrivani
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Department of Chemistry, Durham University, Science Laboratories, South Road, Durham, United Kingdom
| | - Rebecca L. Charlton
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Department of Chemistry, Durham University, Science Laboratories, South Road, Durham, United Kingdom
| | - Marjolly B. Caruso
- Instituto de Bioquímica Médica Leopoldo de Meis (IBqM), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Gabriela A. Burle-Caldas
- Department of Biosciences, Durham University, Science Laboratories, South Road, Durham, United Kingdom
| | - Maria Paula G. Borsodi
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Russolina B. Zingali
- Instituto de Bioquímica Médica Leopoldo de Meis (IBqM), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Natalia Arruda-Costa
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Jéssica B. de Jesus
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | - Stefanie Freitag-Pohl
- Department of Chemistry, Durham University, Science Laboratories, South Road, Durham, United Kingdom
| | - Ehmke Pohl
- Department of Chemistry, Durham University, Science Laboratories, South Road, Durham, United Kingdom
- Department of Biosciences, Durham University, Science Laboratories, South Road, Durham, United Kingdom
| | - Paul W. Denny
- Department of Biosciences, Durham University, Science Laboratories, South Road, Durham, United Kingdom
| | - Bartira Rossi-Bergmann
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- * E-mail: (BR-B); (PGS)
| | - Patrick G. Steel
- Department of Chemistry, Durham University, Science Laboratories, South Road, Durham, United Kingdom
- * E-mail: (BR-B); (PGS)
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Benko Z, Zhang J, Zhao RY. Development of A Fission Yeast Cell-Based Platform for High Throughput Screening of HIV-1 Protease Inhibitors. Curr HIV Res 2021; 17:429-440. [PMID: 31782368 DOI: 10.2174/1570162x17666191128102839] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 11/20/2019] [Accepted: 11/22/2019] [Indexed: 01/18/2023]
Abstract
BACKGROUND HIV-1 protease inhibitor (PI) is one of the most potent classes of drugs in combinational antiretroviral therapies (cART). When a PI is used in combination with other anti- HIV drugs, cART can often suppress HIV-1 below detection thus prolonging the patient's lives. However, the challenge often faced by patients is the emergence of HIV-1 drug resistance. Thus, PIs with high genetic-barrier to drug-resistance are needed. OBJECTIVE The objective of this study was to develop a novel and simple fission yeast (Schizosaccharomyces pombe) cell-based system that is suitable for high throughput screening (HTS) of small molecules against HIV-1 protease (PR). METHODS A fission yeast RE294-GFP strain that stably expresses HIV-1 PR and green fluorescence protein (GFP) under the control of an inducible nmt1 promoter was used. Production of HIV-1 PR induces cellular growth arrest, which was used as the primary endpoint for the search of PIs and was quantified by an absorbance-based method. Levels of GFP production were used as a counter-screen control to eliminate potential transcriptional nmt1 inhibitors. RESULTS Both the absorbance-based HIV-1 PR assay and the GFP-based fluorescence assay were miniaturized and optimized for HTS. A pilot study was performed using a small drug library mixed with known PI drugs and nmt1 inhibitors. With empirically adjusted and clearly defined double-selection criteria, we were able to correctly identify the PIs and to exclude all hidden nmt1 inhibitors. CONCLUSION We have successfully developed and validated a fission yeast cell-based HTS platform for the future screening and testing of HIV-1 PR inhibitors.
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Affiliation(s)
- Zsigmond Benko
- Department of Pathology, University of Maryland Medical School, Baltimore, MD 21201, United States
| | - Jiantao Zhang
- Department of Pathology, University of Maryland Medical School, Baltimore, MD 21201, United States
| | - Richard Y Zhao
- Department of Pathology, University of Maryland Medical School, Baltimore, MD 21201, United States.,Department of Microbiology- Immunology, University of Maryland Medical School, Baltimore, MD 21201, United States.,Institute of Human Virology, University of Maryland Medical School, Baltimore, MD 21201, United States.,Institute of Global Health, University of Maryland Medical School, Baltimore, MD 21201, United States
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Anderson O, Beckett J, Briggs CC, Natrass LA, Cranston CF, Wilkinson EJ, Owen JH, Mir Williams R, Loukaidis A, Bouillon ME, Pritchard D, Lahmann M, Baird MS, Denny PW. An investigation of the antileishmanial properties of semi-synthetic saponins. RSC Med Chem 2020; 11:833-842. [PMID: 33479679 PMCID: PMC7651632 DOI: 10.1039/d0md00123f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 05/21/2020] [Indexed: 12/25/2022] Open
Abstract
Leishmaniasis is a neglected tropical disease caused by insect-vector borne protozoan parasites of the, Leishmania species. Whilst infection threatens and affects millions of the global poor, vaccines are absent and drug therapy limited. Extensive efforts have recently been made to discover new leads from small molecule synthetic compound libraries held by industry; however, the number of new chemical entities identified and entering development as anti-leishmanials has been very low. This has led to increased interest in the possibility of discovering naturally derived compounds with potent antileishmanial activity which may be developed towards clinical applications. Plant-derived triterpenoid and steroidal saponins have long been considered as anti-microbials and here we describe an investigation of a library of 137 natural (9) and semi-synthetic saponins (128) for activity against Leishmania mexicana, a causative agent of cutaneous leishmaniasis. The triterpenoid sapogenin, hederagenin, readily obtained in large quantities from Hedera helix (common ivy), was converted into a range of 128 derivatives. These semi-synthetic compounds, as well as saponins isolated from ivy, were examined with a phenotypic screening approach to identify potent and selective anti-leishmanial hits. This led to the identification of 12 compounds, including the natural saponin gypsogenin, demonstrating high potency (ED50 < 10.5 μM) against axenic L. mexicana amastigotes, the mammalian pathogenic form. One of these, hederagenin disuccinate, was sufficiently non-toxic to the macrophage host cell to facilitate further analyses, selectivity index (SI) > 10. Whilst this was not active in an infected cell model, the anti-leishmanial properties of hederagenin-derivatives have been demonstrated, and the possibility of improving the selectivity of natural hederagenin through chemical modification has been established.
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Affiliation(s)
- Orlagh Anderson
- Department of Biosciences and Centre for Global Infectious Diseases , Durham University , Stockton Road , Durham , DH1 3LE , UK . ; Tel: +44 (0)191 3343983
| | - Joseph Beckett
- Department of Biosciences and Centre for Global Infectious Diseases , Durham University , Stockton Road , Durham , DH1 3LE , UK . ; Tel: +44 (0)191 3343983
| | - Carla C Briggs
- Department of Biosciences and Centre for Global Infectious Diseases , Durham University , Stockton Road , Durham , DH1 3LE , UK . ; Tel: +44 (0)191 3343983
| | - Liam A Natrass
- Department of Biosciences and Centre for Global Infectious Diseases , Durham University , Stockton Road , Durham , DH1 3LE , UK . ; Tel: +44 (0)191 3343983
- Department of Chemistry and Centre for Global Infectious Diseases , Durham University , Stockton Road , Durham , DH1 3LE , UK
| | - Charles F Cranston
- Department of Biosciences and Centre for Global Infectious Diseases , Durham University , Stockton Road , Durham , DH1 3LE , UK . ; Tel: +44 (0)191 3343983
| | - Elizabeth J Wilkinson
- Department of Chemistry , School of Natural Science , Bangor University , Gwynedd LL57 2UW , UK
| | - Jack H Owen
- Department of Chemistry , School of Natural Science , Bangor University , Gwynedd LL57 2UW , UK
| | - Rhodri Mir Williams
- Department of Chemistry , School of Natural Science , Bangor University , Gwynedd LL57 2UW , UK
| | - Angelos Loukaidis
- Department of Chemistry , School of Natural Science , Bangor University , Gwynedd LL57 2UW , UK
| | - Marc E Bouillon
- Department of Chemistry , School of Natural Science , Bangor University , Gwynedd LL57 2UW , UK
| | - Deiniol Pritchard
- Naturiol Bangor Ltd , Alun Roberts Building , Bangor University , Gwynedd LL57 2UW , UK
| | - Martina Lahmann
- Department of Chemistry , School of Natural Science , Bangor University , Gwynedd LL57 2UW , UK
| | - Mark S Baird
- Naturiol Bangor Ltd , Alun Roberts Building , Bangor University , Gwynedd LL57 2UW , UK
| | - Paul W Denny
- Department of Biosciences and Centre for Global Infectious Diseases , Durham University , Stockton Road , Durham , DH1 3LE , UK . ; Tel: +44 (0)191 3343983
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Kokina A, Ozolina Z, Liepins J. Purine auxotrophy: Possible applications beyond genetic marker. Yeast 2019; 36:649-656. [PMID: 31334866 DOI: 10.1002/yea.3434] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/12/2019] [Accepted: 07/16/2019] [Indexed: 01/09/2023] Open
Abstract
Exploring new drug candidates or drug targets against many illnesses is necessary as "traditional" treatments lose their effectivity. Cancer and sicknesses caused by protozoan parasites are among these diseases. Cell purine metabolism is an important drug target. Theoretically, inhibiting purine metabolism could stop the proliferation of unwanted cells. Purine metabolism is similar across all eukaryotes. However, some medically important organisms or cell lines rely on their host purine metabolism. Protozoans causing malaria, leishmaniasis, or toxoplasmosis are purine auxotrophs. Some cancer forms have also lost the ability to synthesize purines de novo. Budding yeast can serve as an effective model for eukaryotic purine metabolism, and thus, purine auxotrophic strains could be an important tool. In this review, we present the common principles of purine metabolism in eukaryotes, effects of purine starvation in eukaryotic cells, and purine-starved Saccharomyces cerevisiae as a model for purine depletion-elicited metabolic states with applications in evolution studies and pharmacology. Purine auxotrophic yeast strains behave differently when growing in media with sufficient supplementation with adenine or in media depleted of adenine (starvation). In the latter, they undergo cell cycle arrest at G1/G0 and become stress resistant. Importantly, similar effects have also been observed among parasitic protozoans or cancer cells. We consider that studies on metabolic changes caused by purine auxotrophy could reveal new options for parasite or cancer therapy. Further, knowledge on phenotypic changes will improve the use of auxotrophic strains in high-throughput screening for primary drug candidates.
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Affiliation(s)
- Agnese Kokina
- Institute of Microbiology and Biotechnology, University of Latvia, Riga, Latvia
| | - Zane Ozolina
- Institute of Microbiology and Biotechnology, University of Latvia, Riga, Latvia
| | - Janis Liepins
- Institute of Microbiology and Biotechnology, University of Latvia, Riga, Latvia
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Getz RA, Kwak G, Cornell S, Mbugua S, Eberhard J, Huang SX, Abbasi Z, de Medeiros AS, Thomas R, Bukowski B, Dranchak PK, Inglese J, Hoffman CS. A fission yeast platform for heterologous expression of mammalian adenylyl cyclases and high throughput screening. Cell Signal 2019; 60:114-121. [PMID: 31026495 DOI: 10.1016/j.cellsig.2019.04.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 04/12/2019] [Accepted: 04/22/2019] [Indexed: 01/18/2023]
Abstract
The fission yeast Schizosaccharomyces pombe uses a cAMP signaling pathway to link glucose-sensing to Protein Kinase A activity in order to regulate cell growth, sexual development, gluconeogenesis, and exit from stationary phase. We previously used a PKA-repressed fbp1-ura4 reporter to conduct high throughput screens (HTSs) for inhibitors of heterologously-expressed mammalian cyclic nucleotide phosphodiesterases (PDEs). Here, we describe the successful expression of all ten mammalian adenylyl cyclase (AC) genes, along with the human GNAS Gαs gene. By measuring expression of an fbp1-GFP reporter together with direct measurements of intracellular cAMP levels, we can detect both basal AC activity from all ten AC genes as well as GNAS-stimulated activity from eight of the nine transmembrane ACs (tmACs; AC2-AC9). The ability to use this platform to conduct HTS for novel chemical probes that reduce PKA activity was demonstrated by a pilot screen of the LOPAC®1280 library, leading to the identification of diphenyleneiodonium chloride (DPI) as an inhibitor of basal AC activity. This screening technology could open the door to the development of therapeutic compounds that target GNAS or the ACs, an area in which there is significant unmet need.
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Affiliation(s)
- Rachel A Getz
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA
| | - Grace Kwak
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA
| | - Stacie Cornell
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA
| | - Samuel Mbugua
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA.
| | - Jeremy Eberhard
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA.
| | - Sheng Xiang Huang
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA.
| | - Zainab Abbasi
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA.
| | | | - Rony Thomas
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA.
| | - Brett Bukowski
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA.
| | - Patricia K Dranchak
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA.
| | - James Inglese
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA.
| | - Charles S Hoffman
- Biology Department, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467, USA.
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11
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Berry SL, Hameed H, Thomason A, Maciej-Hulme ML, Saif Abou-Akkada S, Horrocks P, Price HP. Development of NanoLuc-PEST expressing Leishmania mexicana as a new drug discovery tool for axenic- and intramacrophage-based assays. PLoS Negl Trop Dis 2018; 12:e0006639. [PMID: 30001317 PMCID: PMC6057649 DOI: 10.1371/journal.pntd.0006639] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 07/24/2018] [Accepted: 06/26/2018] [Indexed: 12/12/2022] Open
Abstract
The protozoan parasite Leishmania causes leishmaniasis; a spectrum of diseases of which there are an estimated 1 million new cases each year. Current treatments are toxic, expensive, difficult to administer, and resistance to them is emerging. New therapeutics are urgently needed, however, screening the infective amastigote form of the parasite is challenging. Only certain species can be differentiated into axenic amastigotes, and compound activity against these does not always correlate with efficacy against the parasite in its intracellular niche. Methods used to assess compound efficacy on intracellular amastigotes often rely on microscopy-based assays. These are laborious, require specialist equipment and can only determine parasite burden, not parasite viability. We have addressed this clear need in the anti-leishmanial drug discovery process by producing a transgenic L. mexicana cell line that expresses the luciferase NanoLuc-PEST. We tested the sensitivity and versatility of this transgenic strain, in comparison with strains expressing NanoLuc and the red-shifted firefly luciferase. We then compared the NanoLuc-PEST luciferase to the current methods in both axenic and intramacrophage amastigotes following treatment with a supralethal dose of Amphotericin B. NanoLuc-PEST was a more dynamic indicator of cell viability due to its high turnover rate and high signal:background ratio. This, coupled with its sensitivity in the intramacrophage assay, led us to validate the NanoLuc-PEST expressing cell line using the MMV Pathogen Box in a two-step process: i) identify hits against axenic amastigotes, ii) screen these hits using our bioluminescence-based intramacrophage assay. The data obtained from this highlights the potential of compounds active against M. tuberculosis to be re-purposed for use against Leishmania. Our transgenic L. mexicana cell line is therefore a highly sensitive and dynamic system suitable for Leishmania drug discovery in axenic and intramacrophage amastigote models. The protozoan parasite Leishmania causes a spectrum of diseases collectively known as leishmaniasis. The parasite is transmitted to humans by the bite of its vector, the sand fly, following which the parasite invades host white blood cells, particularly macrophages. Leishmaniasis is classified as a neglected tropical disease, and is endemic in 97 countries. Symptoms of the disease depend on the species of Leishmania. These include skin lesions, destruction of the mucosal membranes, and the visceral form which is usually fatal if untreated. Current therapeutic options for leishmaniasis have a number of associated problems that include toxicity, the development of drug resistance and poor patient compliance due to lengthy and painful treatment regimens. New therapeutics are therefore urgently needed. The ability to screen potential drug candidates requires robust screening assays. Currently, screening the intracellular parasite relies on microscopy-based techniques that require expensive equipment, are time consuming and only detect parasite burden, not viability. By using a transgenic cell line that expresses the NanoLuc-PEST luciferase, we show that we have a parasite-specific viability marker that can be used to measure the efficacy of compounds against the intracellular parasite. We validate the potential of this cell line by screening the MMV Pathogen Box.
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Affiliation(s)
- Sarah L. Berry
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Newcastle-under-Lyme, Staffordshire, United Kingdom
| | - Hamza Hameed
- Institute for Science and Technology in Medicine, Keele University, Newcastle-under-Lyme, Staffordshire, United Kingdom
| | - Anna Thomason
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Newcastle-under-Lyme, Staffordshire, United Kingdom
- Current address: School of Environment and Life Sciences, University of Salford, Salford, United Kingdom
| | - Marissa L. Maciej-Hulme
- Radboud University Medical Center, Department of Nephrology, Geert Grooteplein 10, GA Nijmegan, The Netherlands
| | - Somaia Saif Abou-Akkada
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Newcastle-under-Lyme, Staffordshire, United Kingdom
- Faculty of Veterinary Medicine, Alexandria University, Alexandria, Egypt
| | - Paul Horrocks
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Newcastle-under-Lyme, Staffordshire, United Kingdom
- Institute for Science and Technology in Medicine, Keele University, Newcastle-under-Lyme, Staffordshire, United Kingdom
| | - Helen P. Price
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Newcastle-under-Lyme, Staffordshire, United Kingdom
- * E-mail:
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12
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Weng HB, Chen HX, Wang MW. Innovation in neglected tropical disease drug discovery and development. Infect Dis Poverty 2018; 7:67. [PMID: 29950174 PMCID: PMC6022351 DOI: 10.1186/s40249-018-0444-1] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 05/23/2018] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Neglected tropical diseases (NTDs) are closely related to poverty and affect over a billion people in developing countries. The unmet treatment needs cause high mortality and disability thereby imposing a huge burden with severe social and economic consequences. Although coordinated by the World Health Organization, various philanthropic organizations, national governments and the pharmaceutical industry have been making efforts in improving the situation, the control of NTDs is still inadequate and extremely difficult today. The lack of safe, effective and affordable medicines is a key contributing factor. This paper reviews the recent advances and some of the challenges that we are facing in the fight against NTDs. MAIN BODY In recent years, a number of innovations have demonstrated propensity to promote drug discovery and development for NTDs. Implementation of multilateral collaborations leads to continued efforts and plays a crucial role in drug discovery. Proactive approaches and advanced technologies are urgently needed in drug innovation for NTDs. However, the control and elimination of NTDs remain a formidable task as it requires persistent international cooperation to make sustainable progresses for a long period of time. Some currently employed strategies were proposed and verified to be successful, which involve both mechanisms of 'Push' which aims at cutting the cost of research and development for industry and 'Pull' which aims at increasing market attractiveness. Coupled to this effort should be the exercise of shared responsibility globally to reduce risks, overcome obstacles and maximize benefits. Since NTDs are closely associated with poverty, it is absolutely essential that the stakeholders take concerted and long-term measures to meet multifaceted challenges by alleviating extreme poverty, strengthening social intervention, adapting climate changes, providing effective monitoring and ensuring timely delivery. CONCLUSIONS The ongoing endeavor at the global scale will ultimately benefit the patients, the countries they are living and, hopefully, the manufacturers who provide new preventive, diagnostic and therapeutic products.
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Affiliation(s)
- Hong-Bo Weng
- School of Pharmacy, Fudan University, 826 Zhangheng Road, Pudong New District, Shanghai, 201203 China
| | - Hai-Xia Chen
- School of Pharmacy, Fudan University, 826 Zhangheng Road, Pudong New District, Shanghai, 201203 China
| | - Ming-Wei Wang
- School of Pharmacy, Fudan University, 826 Zhangheng Road, Pudong New District, Shanghai, 201203 China
- The National Center for Drug Screening and the CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences (CAS), 189 Guoshoujing Road, Pudong New District, Shanghai, 201203 China
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Pudong New District, Shanghai, 201210 China
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13
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Norcliffe JL, Mina JG, Alvarez E, Cantizani J, de Dios-Anton F, Colmenarejo G, Valle SGD, Marco M, Fiandor JM, Martin JJ, Steel PG, Denny PW. Identifying inhibitors of the Leishmania inositol phosphorylceramide synthase with antiprotozoal activity using a yeast-based assay and ultra-high throughput screening platform. Sci Rep 2018; 8:3938. [PMID: 29500420 PMCID: PMC5834442 DOI: 10.1038/s41598-018-22063-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 02/16/2018] [Indexed: 01/07/2023] Open
Abstract
Leishmaniasis is a Neglected Tropical Disease caused by the insect-vector borne protozoan parasite, Leishmania species. Infection affects millions of the world’s poorest, however vaccines are absent and drug therapy limited. Recently, public-private partnerships have developed to identify new modes of controlling leishmaniasis. Drug discovery is a significant part of these efforts and here we describe the development and utilization of a novel assay to identify antiprotozoal inhibitors of the Leishmania enzyme, inositol phosphorylceramide (IPC) synthase. IPC synthase is a membrane-bound protein with multiple transmembrane domains, meaning that a conventional in vitro assay using purified protein in solution is highly challenging. Therefore, we utilized Saccharomyces cerevisiae as a vehicle to facilitate ultra-high throughput screening of 1.8 million compounds. Antileishmanial benzazepanes were identified and shown to inhibit the enzyme at nanomolar concentrations. Further chemistry produced a benzazepane that demonstrated potent and specific inhibition of IPC synthase in the Leishmania cell.
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Affiliation(s)
- Jennifer L Norcliffe
- Department of Biosciences, Durham University, Stockton Road, Durham, DH1 3LE, UK.,Department of Chemistry, Durham University, Stockton Road, Durham, DH1 3LE, UK
| | - John G Mina
- Department of Biosciences, Durham University, Stockton Road, Durham, DH1 3LE, UK.,Department of Chemistry, Durham University, Stockton Road, Durham, DH1 3LE, UK
| | - Emilio Alvarez
- GlaxoSmithKline Investigacion y Desarrollo, Parque Tecnologico de Madrid, 28760, Tres Cantos, Madrid, Spain
| | - Juan Cantizani
- GlaxoSmithKline Investigacion y Desarrollo, Parque Tecnologico de Madrid, 28760, Tres Cantos, Madrid, Spain
| | - Francisco de Dios-Anton
- GlaxoSmithKline Investigacion y Desarrollo, Parque Tecnologico de Madrid, 28760, Tres Cantos, Madrid, Spain
| | - Gonzalo Colmenarejo
- GlaxoSmithKline Investigacion y Desarrollo, Parque Tecnologico de Madrid, 28760, Tres Cantos, Madrid, Spain.,Biostatistics and Bioinformatics Unit, IMDEA Food Institute, CEI UAM and CSIC, Carretera de Cantoblanco 8, 28049, Madrid, Spain
| | - Silva Gonzalez-Del Valle
- GlaxoSmithKline Investigacion y Desarrollo, Parque Tecnologico de Madrid, 28760, Tres Cantos, Madrid, Spain
| | - Maria Marco
- GlaxoSmithKline Investigacion y Desarrollo, Parque Tecnologico de Madrid, 28760, Tres Cantos, Madrid, Spain
| | - José M Fiandor
- GlaxoSmithKline Investigacion y Desarrollo, Parque Tecnologico de Madrid, 28760, Tres Cantos, Madrid, Spain
| | - Julio J Martin
- GlaxoSmithKline Investigacion y Desarrollo, Parque Tecnologico de Madrid, 28760, Tres Cantos, Madrid, Spain
| | - Patrick G Steel
- Department of Chemistry, Durham University, Stockton Road, Durham, DH1 3LE, UK.
| | - Paul W Denny
- Department of Biosciences, Durham University, Stockton Road, Durham, DH1 3LE, UK.
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14
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Mina JGM, Denny PW. Everybody needs sphingolipids, right! Mining for new drug targets in protozoan sphingolipid biosynthesis. Parasitology 2018; 145:134-147. [PMID: 28637533 PMCID: PMC5964470 DOI: 10.1017/s0031182017001081] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 05/15/2017] [Accepted: 05/18/2017] [Indexed: 12/18/2022]
Abstract
Sphingolipids (SLs) are an integral part of all eukaryotic cellular membranes. In addition, they have indispensable functions as signalling molecules controlling a myriad of cellular events. Disruption of either the de novo synthesis or the degradation pathways has been shown to have detrimental effects. The earlier identification of selective inhibitors of fungal SL biosynthesis promised potent broad-spectrum anti-fungal agents, which later encouraged testing some of those agents against protozoan parasites. In this review we focus on the key enzymes of the SL de novo biosynthetic pathway in protozoan parasites of the Apicomplexa and Kinetoplastidae, outlining the divergence and interconnection between host and pathogen metabolism. The druggability of the SL biosynthesis is considered, alongside recent technology advances that will enable the dissection and analyses of this pathway in the parasitic protozoa. The future impact of these advances for the development of new therapeutics for both globally threatening and neglected infectious diseases is potentially profound.
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Affiliation(s)
- John G M Mina
- Department of Biosciences,Lower Mountjoy,Stockton Road,Durham DH1 3LE,UK
| | - P W Denny
- Department of Biosciences,Lower Mountjoy,Stockton Road,Durham DH1 3LE,UK
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15
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Denny PW. Microbial protein targets: towards understanding and intervention. Parasitology 2018; 145:111-115. [PMID: 29143719 PMCID: PMC5817423 DOI: 10.1017/s0031182017002037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 10/06/2017] [Accepted: 10/06/2017] [Indexed: 12/11/2022]
Abstract
The rise of antimicrobial resistance, coupled with a lack of industrial focus on antimicrobial discovery over preceding decades, has brought the world to a crisis point. With both human and animal health set to decline due to increased disease burdens caused by near untreatable microbial pathogens, there is an urgent need to identify new antimicrobials. Central to this is the elucidation of new, robustly validated, drug targets. Informed by industrial practice and concerns, the use of both biological and chemical tools in validation is key. In parallel, repurposing approved drugs for use as antimicrobials may provide both new treatments and identify new targets, whilst improved understanding of pharmacology will help develop and progress good 'hits' with the required rapidity. In recognition of the need to increase research efforts in these areas, in 14-16 September 2017, the British Society for Parasitology (BSP) Autumn Symposium was hosted at Durham University with the title: Microbial Protein Targets: towards understanding and intervention. Staged in collaboration with the Royal Society of Chemistry (RSC) Chemistry Biology Interface Division (CBID), the core aim was to bring together leading researchers working across disciplines to imagine novel approaches towards combating infection and antimicrobial resistance. Sessions were held on: 'Anti-infective discovery, an overview'; 'Omic approaches to target validation'; 'Genetic approaches to target validation'; 'Drug target structure and drug discovery'; 'Fragment-based approaches to drug discovery'; and 'Chemical approaches to target validation'. Here, we introduce a series of review and primary research articles from selected contributors to the Symposium, giving an overview of progress in understanding antimicrobial targets and developing new drugs. The Symposium was organized by Paul Denny (Durham) for the BSP and Patrick Steel (Durham) for RSC CBID.
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Affiliation(s)
- Paul W Denny
- Department of Biosciences,Durham University,Lower Mountjoy, Stockton Road, Durham DH1 3LE,UK
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16
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Yeast-Based High-Throughput Screens to Identify Novel Compounds Active against Brugia malayi. PLoS Negl Trop Dis 2016; 10:e0004401. [PMID: 26812604 PMCID: PMC4727890 DOI: 10.1371/journal.pntd.0004401] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 12/31/2015] [Indexed: 12/02/2022] Open
Abstract
Background Lymphatic filariasis is caused by the parasitic worms Wuchereria bancrofti, Brugia malayi or B. timori, which are transmitted via the bites from infected mosquitoes. Once in the human body, the parasites develop into adult worms in the lymphatic vessels, causing severe damage and swelling of the affected tissues. According to the World Health Organization, over 1.2 billion people in 58 countries are at risk of contracting lymphatic filariasis. Very few drugs are available to treat patients infected with these parasites, and these have low efficacy against the adult stages of the worms, which can live for 7–15 years in the human body. The requirement for annual treatment increases the risk of drug-resistant worms emerging, making it imperative to develop new drugs against these devastating diseases. Methodology/Principal Findings We have developed a yeast-based, high-throughput screening system whereby essential yeast genes are replaced with their filarial or human counterparts. These strains are labeled with different fluorescent proteins to allow the simultaneous monitoring of strains with parasite or human genes in competition, and hence the identification of compounds that inhibit the parasite target without affecting its human ortholog. We constructed yeast strains expressing eight different Brugia malayi drug targets (as well as seven of their human counterparts), and performed medium-throughput drug screens for compounds that specifically inhibit the parasite enzymes. Using the Malaria Box collection (400 compounds), we identified nine filarial specific inhibitors and confirmed the antifilarial activity of five of these using in vitro assays against Brugia pahangi. Conclusions/Significance We were able to functionally complement yeast deletions with eight different Brugia malayi enzymes that represent potential drug targets. We demonstrated that our yeast-based screening platform is efficient in identifying compounds that can discriminate between human and filarial enzymes. Hence, we are confident that we can extend our efforts to the construction of strains with further filarial targets (in particular for those species that cannot be cultivated in the laboratory), and perform high-throughput drug screens to identify specific inhibitors of the parasite enzymes. By establishing synergistic collaborations with researchers working directly on different parasitic worms, we aim to aid antihelmintic drug development for both human and veterinary infections. We have developed and validated a yeast-based high-throughput screening assay for the identification of specific inhibitors of filarial targets. We engineered yeast strains to functionally express parasite and human enzymes, labeling these with fluorescent proteins and growing them in competition in the presence of test compounds. These strains express different target proteins from Brugia malayi (as well as their human orthologs) and our results demonstrate that it is possible to identify compounds that can discriminate between filarial and human enzymes. Accordingly, we are confident that we can extend our assay to novel targets from Brugia malayi and other worms of medical and veterinary importance, and perform high-throughput screens to identify new drugs against different parasitic worms.
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17
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Martin-Plaza J, Chatelain E. Novel therapeutic approaches for neglected infectious diseases. ACTA ACUST UNITED AC 2015; 20:3-5. [PMID: 25542923 DOI: 10.1177/1087057114559907] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
| | - Eric Chatelain
- Drugs for Neglected Disease initiative (DNDi), Geneva, Switzerland
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