1
|
Simwela NV, Guiguemde WA, Straimer J, Regnault C, Stokes BH, Tavernelli LE, Yokokawa F, Taft B, Diagana TT, Barrett MP, Waters AP. A conserved metabolic signature associated with response to fast-acting anti-malarial agents. Microbiol Spectr 2023; 11:e0397622. [PMID: 37800971 PMCID: PMC10714989 DOI: 10.1128/spectrum.03976-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Accepted: 01/27/2023] [Indexed: 10/07/2023] Open
Abstract
IMPORTANCE In malaria drug discovery, understanding the mode of action of lead compounds is important as it helps in predicting the potential emergence of drug resistance in the field when these drugs are eventually deployed. In this study, we have employed metabolomics technologies to characterize the potential targets of anti-malarial drug candidates in the developmental pipeline at NITD. We show that NITD fast-acting leads belonging to spiroindolone and imidazothiadiazole class induce a common biochemical theme in drug-exposed malaria parasites which is similar to another fast-acting, clinically available drug, DHA. These biochemical features which are absent in a slower acting NITD lead (GNF17) point to hemoglobin digestion and inhibition of the pyrimidine pathway as potential action points for these drugs. These biochemical themes can be used to identify and inform on the mode of action of fast drug candidates of similar profiles in future drug discovery programs.
Collapse
Affiliation(s)
- Nelson V. Simwela
- Institute of Infection, Immunity and Inflammation, Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, United Kingdom
| | | | - Judith Straimer
- Novartis Institute for Tropical Diseases, Emeryville, California, USA
| | - Clement Regnault
- Institute of Infection, Immunity and Inflammation, Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, United Kingdom
| | - Barbara H. Stokes
- Institute of Infection, Immunity and Inflammation, Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, United Kingdom
| | - Luis E. Tavernelli
- Institute of Infection, Immunity and Inflammation, Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, United Kingdom
| | - Fumiaki Yokokawa
- Novartis Institute for Tropical Diseases, Emeryville, California, USA
| | - Benjamin Taft
- Novartis Institute for Tropical Diseases, Emeryville, California, USA
| | | | - Michael P. Barrett
- Institute of Infection, Immunity and Inflammation, Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, United Kingdom
| | - Andrew P. Waters
- Institute of Infection, Immunity and Inflammation, Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, United Kingdom
| |
Collapse
|
2
|
Kina UY, Kamil M, Deveci G, Rafiqi AM, Matuschewski K, Aly ASI. A Candidate Bacterial-Type Amino Acid Decarboxylase Is Essential for Male Gamete Exflagellation and Mosquito Transmission of the Malaria Parasite. Infect Immun 2023; 91:e0016723. [PMID: 37260388 PMCID: PMC10353352 DOI: 10.1128/iai.00167-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 05/07/2023] [Indexed: 06/02/2023] Open
Abstract
A frequent side effect of chemotherapy against malaria parasite blood infections is a dramatic induction of the sexual blood stages, thereby enhancing the risk of future malaria transmissions. The polyamine biosynthesis pathway has been suggested as a candidate target for transmission-blocking anti-malarial drug development. Herein, we describe the role of a bacterial-type amino acid decarboxylase (AAD) in the life cycle of the malaria model parasite Plasmodium yoelii. Hallmarks of AAD include a conserved catalytic lysine residue and high-level homology to arginine/lysine/ornithine decarboxylases of pathogenic bacteria. By targeted gene deletion, we show that AAD plays an essential role in the exflagellation of microgametes, resulting in complete absence of sporozoites in the mosquito vector. These data highlight the central role of the biosysthesis of polyamines in the final steps of male gamete sexual development of the malaria parasite and, hence, onward transmission to mosquitoes.
Collapse
Affiliation(s)
- Umit Y. Kina
- Aly lab, Beykoz Institute of Life Sciences and Biotechnology, Bezmialem Vakif University, Istanbul, Turkey
- Department of Biotechnology, Institute of Health Sciences, Bezmialem Vakif University, Istanbul, Turkey
| | - Mohd Kamil
- Aly lab, Beykoz Institute of Life Sciences and Biotechnology, Bezmialem Vakif University, Istanbul, Turkey
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Gozde Deveci
- Aly lab, Beykoz Institute of Life Sciences and Biotechnology, Bezmialem Vakif University, Istanbul, Turkey
| | - Ab. Matteen Rafiqi
- Aly lab, Beykoz Institute of Life Sciences and Biotechnology, Bezmialem Vakif University, Istanbul, Turkey
| | - Kai Matuschewski
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, Berlin, Germany
| | - Ahmed S. I. Aly
- Aly lab, Beykoz Institute of Life Sciences and Biotechnology, Bezmialem Vakif University, Istanbul, Turkey
- School of Science and Engineering, Al Akhawayn University, Ifrane, Morocco
| |
Collapse
|
3
|
Schneider V, Visone J, Harris C, Florini F, Hadjimichael E, Zhang X, Gross M, Rhee K, Ben Mamoun C, Kafsack B, Deitsch K. The human malaria parasite Plasmodium falciparum can sense environmental changes and respond by antigenic switching. Proc Natl Acad Sci U S A 2023; 120:e2302152120. [PMID: 37068249 PMCID: PMC10151525 DOI: 10.1073/pnas.2302152120] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 03/20/2023] [Indexed: 04/19/2023] Open
Abstract
The primary antigenic and virulence determinant of the human malaria parasite Plasmodium falciparum is a variant surface protein called PfEMP1. Different forms of PfEMP1 are encoded by a multicopy gene family called var, and switching between active genes enables the parasites to evade the antibody response of their human hosts. var gene switching is key for the maintenance of chronic infections; however, what controls switching is unknown, although it has been suggested to occur at a constant frequency with little or no environmental influence. var gene transcription is controlled epigenetically through the activity of histone methyltransferases (HMTs). Studies in model systems have shown that metabolism and epigenetic control of gene expression are linked through the availability of intracellular S-adenosylmethionine (SAM), the principal methyl donor in biological methylation modifications, which can fluctuate based on nutrient availability. To determine whether environmental conditions and changes in metabolism can influence var gene expression, P. falciparum was cultured in media with altered concentrations of nutrients involved in SAM metabolism. We found that conditions that influence lipid metabolism induce var gene switching, indicating that parasites can respond to changes in their environment by altering var gene expression patterns. Genetic modifications that directly modified expression of the enzymes that control SAM levels similarly led to profound changes in var gene expression, confirming that changes in SAM availability modulate var gene switching. These observations directly challenge the paradigm that antigenic variation in P. falciparum follows an intrinsic, programed switching rate, which operates independently of any external stimuli.
Collapse
Affiliation(s)
- Victoria M. Schneider
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
- Laboratory of Chemical Biology and Microbial Pathogenesis, Rockefeller University, New York, NY 10065
| | - Joseph E. Visone
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
| | - Chantal T. Harris
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
| | - Francesca Florini
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
| | - Evi Hadjimichael
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
| | - Xu Zhang
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
| | - Mackensie R. Gross
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
| | - Kyu Y. Rhee
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
| | - Choukri Ben Mamoun
- Section of Infectious Disease, Department of Microbial Pathogenesis, Yale School of Medicine, Yale University New Haven, CT 06510
| | - Björn F. C. Kafsack
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
| | - Kirk W. Deitsch
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, Ithaca, NY14853
| |
Collapse
|
4
|
Cripowellins Pause Plasmodium falciparum Intraerythrocytic Development at the Ring Stage. Molecules 2023; 28:molecules28062600. [PMID: 36985570 PMCID: PMC10056369 DOI: 10.3390/molecules28062600] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 02/19/2023] [Accepted: 03/08/2023] [Indexed: 03/18/2023] Open
Abstract
Cripowellins from Crinum erubescens are known pesticidal and have potent antiplasmodial activity. To gain mechanistic insights to this class of natural products, studies to determine the timing of action of cripowellins within the asexual intraerythrocytic cycle of Plasmodium falciparum were performed and led to the observation that this class of natural products induced reversible cytostasis in the ring stage within the first 24 h of treatment. The transcriptional program necessary for P. falciparum to progress through the asexual intraerythrocytic life cycle is well characterized. Whole transcriptome abundance analysis showed that cripowellin B “pauses” the transcriptional program necessary to progress through the intraerythrocytic life cycle coinciding with the lack of morphological progression of drug treated parasites. In addition, cripowellin B-treated parasites re-enter transcriptional progression after treatment was removed. This study highlights the use of cripowellins as chemical probes to reveal new aspects of cell cycle progression of the asexual ring stage of P. falciparum which could be leveraged for the generation of future antimalarial therapeutics.
Collapse
|
5
|
Marreiros IM, Marques S, Parreira A, Mastrodomenico V, Mounce BC, Harris CT, Kafsack BF, Billker O, Zuzarte-Luís V, Mota MM. A non-canonical sensing pathway mediates Plasmodium adaptation to amino acid deficiency. Commun Biol 2023; 6:205. [PMID: 36810637 PMCID: PMC9942083 DOI: 10.1038/s42003-023-04566-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 02/08/2023] [Indexed: 02/23/2023] Open
Abstract
Eukaryotes have canonical pathways for responding to amino acid (AA) availability. Under AA-limiting conditions, the TOR complex is repressed, whereas the sensor kinase GCN2 is activated. While these pathways have been highly conserved throughout evolution, malaria parasites are a rare exception. Despite auxotrophic for most AA, Plasmodium does not have either a TOR complex nor the GCN2-downstream transcription factors. While Ile starvation has been shown to trigger eIF2α phosphorylation and a hibernation-like response, the overall mechanisms mediating detection and response to AA fluctuation in the absence of such pathways has remained elusive. Here we show that Plasmodium parasites rely on an efficient sensing pathway to respond to AA fluctuations. A phenotypic screen of kinase knockout mutant parasites identified nek4, eIK1 and eIK2-the last two clustering with the eukaryotic eIF2α kinases-as critical for Plasmodium to sense and respond to distinct AA-limiting conditions. Such AA-sensing pathway is temporally regulated at distinct life cycle stages, allowing parasites to actively fine-tune replication and development in response to AA availability. Collectively, our data disclose a set of heterogeneous responses to AA depletion in malaria parasites, mediated by a complex mechanism that is critical for modulating parasite growth and survival.
Collapse
Affiliation(s)
- Inês M. Marreiros
- grid.9983.b0000 0001 2181 4263Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal ,grid.5808.50000 0001 1503 7226Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Sofia Marques
- grid.9983.b0000 0001 2181 4263Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Ana Parreira
- grid.9983.b0000 0001 2181 4263Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Vincent Mastrodomenico
- grid.164971.c0000 0001 1089 6558Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL USA
| | - Bryan C. Mounce
- grid.164971.c0000 0001 1089 6558Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL USA ,grid.164971.c0000 0001 1089 6558Infectious Disease and Immunology Research Institute, Stritch School of Medicine, Loyola University Chicago, Maywood, IL USA
| | - Chantal T. Harris
- grid.5386.8000000041936877XDepartment of Microbiology and Immunology, Weill Cornell Medical College, New York, NY USA ,grid.5386.8000000041936877XImmunology & Microbial Pathogenesis Graduate Program, Weill Cornell Medicine, New York, NY USA
| | - Björn F. Kafsack
- grid.5386.8000000041936877XDepartment of Microbiology and Immunology, Weill Cornell Medical College, New York, NY USA
| | - Oliver Billker
- grid.12650.300000 0001 1034 3451Molecular Infection Medicine Sweden, Molecular Biology Department, Umeå University, Umeå, S-90187 Sweden
| | - Vanessa Zuzarte-Luís
- grid.9983.b0000 0001 2181 4263Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Maria M. Mota
- grid.9983.b0000 0001 2181 4263Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| |
Collapse
|
6
|
An Undefined Interaction between Polyamines and Heat Shock Proteins Leads to Cellular Protection in Plasmodium falciparum and Proliferating Cells in Various Organisms. Molecules 2023; 28:molecules28041686. [PMID: 36838674 PMCID: PMC9958663 DOI: 10.3390/molecules28041686] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 02/06/2023] [Indexed: 02/12/2023] Open
Abstract
Environmental stimuli can distress the internal reaction of cells and their normal function. To react promptly to sudden environmental changes, a cascade of heat shock proteins (Hsps) functions to protect and act as housekeepers inside the cells. In parallel to the heat shock response, the metabolic polyamine (PA) status changes. Here, we discuss possible ways of putative interactions between Hsps and polyamines in a wide lineage of eukaryotic model organisms with a particular focus on parasitic protozoa such as Plasmodium falciparum (P. falciparum). The supposed interaction between polyamines and Hsps may protect the parasite from the sudden change in temperature during transmission from the female Anopheles mosquito to a human host. Recent experiments performed with the spermidine mimetic inhibitor 15-deoxyspergualine in Plasmodium in vitro cultures show that the drug binds to the C-terminal EEVD motif of Hsp70. This leads to inhibition of protein biosynthesis caused by prevention of eIF5A2 phosphorylation and eukaryotic initiation factor 5A (eIF5A) modification. These observations provide further evidence that PAs are involved in the regulation of protein biosynthesis of Hsps to achieve a protective effect for the parasite during transmission.
Collapse
|
7
|
Structure- and ligand-based drug design methods for the modeling of antimalarial agents: a review of updates from 2012 onwards. J Biomol Struct Dyn 2022; 40:10481-10506. [PMID: 34129805 DOI: 10.1080/07391102.2021.1932598] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Malaria still persists as one of the deadliest infectious disease having a huge morbidity and mortality affecting the higher population of the world. Structure and ligand-based drug design methods like molecular docking and MD simulations, pharmacophore modeling, QSAR and virtual screening are widely used to perceive the accordant correlation between the antimalarial activity and property of the compounds to design novel dominant and discriminant molecules. These modeling methods will speed-up antimalarial drug discovery, selection of better drug candidates for synthesis and to achieve potent and safer drugs. In this work, we have extensively reviewed the literature pertaining to the use and applications of various ligand and structure-based computational methods for the design of antimalarial agents. Different classes of molecules are discussed along with their target interactions pattern, which is responsible for antimalarial activity. Communicated by Ramaswamy H. Sarma.
Collapse
|
8
|
Challis MP, Devine SM, Creek DJ. Current and emerging target identification methods for novel antimalarials. Int J Parasitol Drugs Drug Resist 2022; 20:135-144. [PMID: 36410177 PMCID: PMC9771836 DOI: 10.1016/j.ijpddr.2022.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/04/2022] [Accepted: 11/07/2022] [Indexed: 11/13/2022]
Abstract
New antimalarial compounds with novel mechanisms of action are urgently needed to combat the recent rise in antimalarial drug resistance. Phenotypic high-throughput screens have proven to be a successful method for identifying new compounds, however, do not provide mechanistic information about the molecular target(s) responsible for antimalarial action. Current and emerging target identification methods such as in vitro resistance generation, metabolomics screening, chemoproteomic approaches and biophysical assays measuring protein stability across the whole proteome have successfully identified novel drug targets. This review provides an overview of these techniques, comparing their strengths and weaknesses and how they can be utilised for antimalarial target identification.
Collapse
Affiliation(s)
- Matthew P. Challis
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria, 3052, Australia
| | - Shane M. Devine
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria, 3052, Australia
| | - Darren J. Creek
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria, 3052, Australia,Corresponding author. Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia.
| |
Collapse
|
9
|
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.
Collapse
|
10
|
Plasmodium falciparum S-Adenosylmethionine Synthetase Is Essential for Parasite Survival through a Complex Interaction Network with Cytoplasmic and Nuclear Proteins. Microorganisms 2022; 10:microorganisms10071419. [PMID: 35889137 PMCID: PMC9320499 DOI: 10.3390/microorganisms10071419] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/01/2022] [Accepted: 07/11/2022] [Indexed: 11/16/2022] Open
Abstract
S-adenosylmethionine synthetase (SAMS) is a key enzyme for the synthesis of the lone methyl donor S-adenosyl methionine (SAM), which is involved in transmethylation reactions and hence required for cellular processes such as DNA, RNA, and histone methylation, but also polyamine biosynthesis and proteostasis. In the human malaria parasite Plasmodium falciparum, PfSAMS is encoded by a single gene and has been suggested to be crucial for malaria pathogenesis and transmission; however, to date, PfSAMS has not been fully characterized. To gain deeper insight into the function of PfSAMS, we generated a conditional gene knockdown (KD) using the glmS ribozyme system. We show that PfSAMS localizes to the cytoplasm and the nucleus of blood-stage parasites. PfSAMS-KD results in reduced histone methylation and leads to impaired intraerythrocytic growth and gametocyte development. To further determine the interaction network of PfSAMS, we performed a proximity-dependent biotin identification analysis. We identified a complex network of 1114 proteins involved in biological processes such as cell cycle control and DNA replication, or transcription, but also in phosphatidylcholine and polyamine biosynthesis and proteasome regulation. Our findings highlight the diverse roles of PfSAMS during intraerythrocytic growth and sexual stage development and emphasize that PfSAMS is a potential drug target.
Collapse
|
11
|
Niemand J, van Biljon R, van der Watt M, van Heerden A, Reader J, van Wyk R, Orchard L, Chibale K, Llinás M, Birkholtz LM. Chemogenomic Fingerprints Associated with Stage-Specific Gametocytocidal Compound Action against Human Malaria Parasites. ACS Infect Dis 2021; 7:2904-2916. [PMID: 34569223 DOI: 10.1021/acsinfecdis.1c00373] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Kinase-focused inhibitors previously revealed compounds with differential activity against different stages of Plasmodium falciparum gametocytes. MMV666810, a 2-aminopyrazine, is more active on late-stage gametocytes, while a pyrazolopyridine, MMV674850, preferentially targets early-stage gametocytes. Here, we probe the biological mechanisms underpinning this differential stage-specific killing using in-depth transcriptome fingerprinting. Compound-specific chemogenomic profiles were observed with MMV674850 treatment associated with biological processes shared between asexual blood stage parasites and early-stage gametocytes but not late-stage gametocytes. MMV666810 has a distinct profile with clustered gene sets associated primarily with late-stage gametocyte development, including Ca2+-dependent protein kinases (CDPK1 and 5) and serine/threonine protein kinases (FIKK). Chemogenomic profiling therefore highlights essential processes in late-stage gametocytes, on a transcriptional level. This information is important to prioritize compounds that preferentially compromise late-stage gametocytes for further development as transmission-blocking antimalarials.
Collapse
Affiliation(s)
- Jandeli Niemand
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, Pretoria 0028, South Africa
- Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, Pretoria 0028, South Africa
| | - Riëtte van Biljon
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, Pretoria 0028, South Africa
| | - Mariëtte van der Watt
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, Pretoria 0028, South Africa
| | - Ashleigh van Heerden
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, Pretoria 0028, South Africa
| | - Janette Reader
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, Pretoria 0028, South Africa
| | - Roelof van Wyk
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, Pretoria 0028, South Africa
| | - Lindsey Orchard
- Department of Biochemistry & Molecular Biology and the Huck Centre for Malaria Research, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Kelly Chibale
- Drug Discovery and Development Centre (H3D), University of Cape Town, Rondebosch, Cape Town, 7701, South Africa
- South African Medical Research Council, Drug Discovery and Development Research Unit, Department of Chemistry and Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa
| | - Manuel Llinás
- Department of Biochemistry & Molecular Biology and the Huck Centre for Malaria Research, Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Lyn-Marié Birkholtz
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, Pretoria 0028, South Africa
- Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, Pretoria 0028, South Africa
| |
Collapse
|
12
|
van Heerden A, van Wyk R, Birkholtz LM. Machine Learning Uses Chemo-Transcriptomic Profiles to Stratify Antimalarial Compounds With Similar Mode of Action. Front Cell Infect Microbiol 2021; 11:688256. [PMID: 34268139 PMCID: PMC8277430 DOI: 10.3389/fcimb.2021.688256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/04/2021] [Indexed: 11/26/2022] Open
Abstract
The rapid development of antimalarial resistance motivates the continued search for novel compounds with a mode of action (MoA) different to current antimalarials. Phenotypic screening has delivered thousands of promising hit compounds without prior knowledge of the compounds’ exact target or MoA. Whilst the latter is not initially required to progress a compound in a medicinal chemistry program, identifying the MoA early can accelerate hit prioritization, hit-to-lead optimization and preclinical combination studies in malaria research. The effects of drug treatment on a cell can be observed on systems level in changes in the transcriptome, proteome and metabolome. Machine learning (ML) algorithms are powerful tools able to deconvolute such complex chemically-induced transcriptional signatures to identify pathways on which a compound act and in this manner provide an indication of the MoA of a compound. In this study, we assessed different ML approaches for their ability to stratify antimalarial compounds based on varied chemically-induced transcriptional responses. We developed a rational gene selection approach that could identify predictive features for MoA to train and generate ML models. The best performing model could stratify compounds with similar MoA with a classification accuracy of 76.6 ± 6.4%. Moreover, only a limited set of 50 biomarkers was required to stratify compounds with similar MoA and define chemo-transcriptomic fingerprints for each compound. These fingerprints were unique for each compound and compounds with similar targets/MoA clustered together. The ML model was specific and sensitive enough to group new compounds into MoAs associated with their predicted target and was robust enough to be extended to also generate chemo-transcriptomic fingerprints for additional life cycle stages like immature gametocytes. This work therefore contributes a new strategy to rapidly, specifically and sensitively indicate the MoA of compounds based on chemo-transcriptomic fingerprints and holds promise to accelerate antimalarial drug discovery programs.
Collapse
Affiliation(s)
- Ashleigh van Heerden
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, South Africa.,University of Pretoria Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, South Africa
| | - Roelof van Wyk
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, South Africa.,University of Pretoria Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, South Africa
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, South Africa.,University of Pretoria Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, South Africa
| |
Collapse
|
13
|
Zhou M, Varol A, Efferth T. Multi-omics approaches to improve malaria therapy. Pharmacol Res 2021; 167:105570. [PMID: 33766628 DOI: 10.1016/j.phrs.2021.105570] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 03/02/2021] [Accepted: 03/16/2021] [Indexed: 01/07/2023]
Abstract
Malaria contributes to the most widespread infectious diseases worldwide. Even though current drugs are commercially available, the ever-increasing drug resistance problem by malaria parasites poses new challenges in malaria therapy. Hence, searching for efficient therapeutic strategies is of high priority in malaria control. In recent years, multi-omics technologies have been extensively applied to provide a more holistic view of functional principles and dynamics of biological mechanisms. We briefly review multi-omics technologies and focus on recent malaria progress conducted with the help of various omics methods. Then, we present up-to-date advances for multi-omics approaches in malaria. Next, we describe resistance phenomena to established antimalarial drugs and underlying mechanisms. Finally, we provide insight into novel multi-omics approaches, new drugs and vaccine developments and analyze current gaps in multi-omics research. Although multi-omics approaches have been successfully used in malaria studies, they are still limited. Many gaps need to be filled to bridge the gap between basic research and treatment of malaria patients. Multi-omics approaches will foster a better understanding of the molecular mechanisms of Plasmodium that are essential for the development of novel drugs and vaccines to fight this disastrous disease.
Collapse
Affiliation(s)
- Min Zhou
- Department of Pharmaceutical Biology, Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg University, Staudinger Weg 5, 55128 Mainz, Germany
| | - Ayşegül Varol
- Department of Pharmaceutical Biology, Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg University, Staudinger Weg 5, 55128 Mainz, Germany
| | - Thomas Efferth
- Department of Pharmaceutical Biology, Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg University, Staudinger Weg 5, 55128 Mainz, Germany.
| |
Collapse
|
14
|
Facilitating the enzymatic conversion of lysineto cadaverine in engineered Escherichia coli with metabolic regulation by genes deletion. Biochem Eng J 2020. [DOI: 10.1016/j.bej.2020.107514] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
|
15
|
6'-β-Fluoro-Homoaristeromycin and 6'-Fluoro-Homoneplanocin A Are Potent Inhibitors of Chikungunya Virus Replication through Their Direct Effect on Viral Nonstructural Protein 1. Antimicrob Agents Chemother 2020; 64:AAC.02532-19. [PMID: 31964798 PMCID: PMC7179274 DOI: 10.1128/aac.02532-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 01/17/2020] [Indexed: 12/23/2022] Open
Abstract
Alphaviruses are arthropod-borne, positive-stranded RNA viruses capable of causing severe disease with high morbidity. Chikungunya virus (CHIKV) is an alphavirus that causes a febrile illness which can progress into chronic arthralgia. The current lack of vaccines and specific treatment for CHIKV infection underscores the need to develop new therapeutic interventions. To discover new antiviral agents, we performed a compound screen in cell culture-based infection models and identified two carbocyclic adenosine analogues, 6′-β-fluoro-homoaristeromycin (FHA) and 6′-fluoro-homoneplanocin A (FHNA), that displayed potent activity against CHIKV and Semliki Forest virus (SFV) with 50% effective concentrations in the nanomolar range at nontoxic concentrations. Alphaviruses are arthropod-borne, positive-stranded RNA viruses capable of causing severe disease with high morbidity. Chikungunya virus (CHIKV) is an alphavirus that causes a febrile illness which can progress into chronic arthralgia. The current lack of vaccines and specific treatment for CHIKV infection underscores the need to develop new therapeutic interventions. To discover new antiviral agents, we performed a compound screen in cell culture-based infection models and identified two carbocyclic adenosine analogues, 6′-β-fluoro-homoaristeromycin (FHA) and 6′-fluoro-homoneplanocin A (FHNA), that displayed potent activity against CHIKV and Semliki Forest virus (SFV) with 50% effective concentrations in the nanomolar range at nontoxic concentrations. The compounds, designed as inhibitors of the host enzyme S-adenosylhomocysteine (SAH) hydrolase, impeded postentry steps in CHIKV and SFV replication. Selection of FHNA-resistant mutants and reverse genetics studies demonstrated that the combination of mutations G230R and K299E in CHIKV nonstructural protein 1 (nsP1) conferred resistance to the compounds. Enzymatic assays with purified wild-type (wt) SFV nsP1 suggested that an oxidized (3′-keto) form, rather than FHNA itself, directly inhibited the MTase activity, while a mutant protein with the K231R and K299E substitutions was insensitive to the compound. Both wt nsP1 and the resistant mutant were equally sensitive to the inhibitory effect of SAH. Our combined data suggest that FHA and FHNA inhibit CHIKV and SFV replication by directly targeting the MTase activity of nsP1, rather than through an indirect effect on host SAH hydrolase. The high potency and selectivity of these novel alphavirus mRNA capping inhibitors warrant further preclinical investigation of these compounds.
Collapse
|
16
|
Cobbold SA, McConville MJ. Determining the Mode of Action of Antimalarial Drugs Using Time-Resolved LC-MS-Based Metabolite Profiling. Methods Mol Biol 2019; 1859:225-239. [PMID: 30421232 DOI: 10.1007/978-1-4939-8757-3_12] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Methods for assessing the mode of action of new antimalarial compounds identified in high throughput phenotypic screens are needed to triage and facilitate lead compound development and to anticipate potential resistance mechanisms that might emerge. Here we describe a mass spectrometry-based approach for detecting metabolic changes in asexual erythrocytic stages of Plasmodium falciparum induced by antimalarial compounds. Time-resolved or concentration-resolved measurements are used to discriminate between putative targets of the compound and nonspecific and/or downstream secondary metabolic effects. These protocols can also be coupled with 13C-stable-isotope tracing experiments under nonequilibrative (or nonstationary) conditions to measure metabolic dynamics following drug exposure. Time-resolved 13C-labeling studies greatly increase confidence in target assignment and provide a more comprehensive understanding of the metabolic perturbations induced by small molecule inhibitors. The protocol provides details on the experimental design, Plasmodium falciparum culture, sample preparation, analytical approaches, and data analysis used in either targeted (pathway focused) or untargeted (all detected metabolites) analysis of drug-induced metabolic perturbations.
Collapse
Affiliation(s)
- Simon A Cobbold
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Malcolm J McConville
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Parkville, 3010, Victoria, Australia.
| |
Collapse
|
17
|
El Bissati K, Redel H, Ting LM, Lykins JD, McPhillie MJ, Upadhya R, Woster PM, Yarlett N, Kim K, Weiss LM. Novel Synthetic Polyamines Have Potent Antimalarial Activities in vitro and in vivo by Decreasing Intracellular Spermidine and Spermine Concentrations. Front Cell Infect Microbiol 2019; 9:9. [PMID: 30838177 PMCID: PMC6382690 DOI: 10.3389/fcimb.2019.00009] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 01/14/2019] [Indexed: 01/09/2023] Open
Abstract
Twenty-two compounds belonging to several classes of polyamine analogs have been examined for their ability to inhibit the growth of the human malaria parasite Plasmodium falciparum in vitro and in vivo. Four lead compounds from the thiourea sub-series and one compound from the urea-based analogs were found to be potent inhibitors of both chloroquine-resistant (Dd2) and chloroquine-sensitive (3D7) strains of Plasmodium with IC50 values ranging from 150 to 460 nM. In addition, the compound RHW, N1,N7-bis (3-(cyclohexylmethylamino) propyl) heptane-1,7-diamine tetrabromide was found to inhibit Dd2 with an IC50 of 200 nM. When RHW was administered to P. yoelii-infected mice at 35 mg/kg for 4 days, it significantly reduced parasitemia. RHW was also assayed in combination with the ornithine decarboxylase inhibitor difluoromethylornithine, and the two drugs were found not to have synergistic antimalarial activity. Furthermore, these inhibitors led to decreased cellular spermidine and spermine levels in P. falciparum, suggesting that they exert their antimalarial activities by inhibition of spermidine synthase.
Collapse
Affiliation(s)
- Kamal El Bissati
- Department of Ophthalmology and Visual Science, The University of Chicago, Chicago, IL, United States
| | - Henry Redel
- Department of Medicine, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, United States
| | - Li-Min Ting
- Department of Medicine, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, United States
| | - Joseph D Lykins
- Department of Internal Medicine and Department of Emergency Medicine, Virginia Commonwealth University Health System, Richmond, VA, United States
| | | | - Rajendra Upadhya
- Department of Medicine, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, United States
| | - Patrick M Woster
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - Nigel Yarlett
- Haskins Laboratories, Department of Chemistry and Physical Sciences, Pace University, New York, NY, United States
| | - Kami Kim
- Department of Medicine, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, United States.,Department of Pathology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, United States
| | - Louis M Weiss
- Department of Medicine, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, United States.,Department of Pathology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, United States
| |
Collapse
|
18
|
Inducing controlled cell cycle arrest and re-entry during asexual proliferation of Plasmodium falciparum malaria parasites. Sci Rep 2018; 8:16581. [PMID: 30409996 PMCID: PMC6224408 DOI: 10.1038/s41598-018-34964-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 10/26/2018] [Indexed: 02/08/2023] Open
Abstract
The life cycle of the malaria parasite Plasmodium falciparum is tightly regulated, oscillating between stages of intense proliferation and quiescence. Cyclic 48-hour asexual replication of Plasmodium is markedly different from cell division in higher eukaryotes, and mechanistically poorly understood. Here, we report tight synchronisation of malaria parasites during the early phases of the cell cycle by exposure to DL-α-difluoromethylornithine (DFMO), which results in the depletion of polyamines. This induces an inescapable cell cycle arrest in G1 (~15 hours post-invasion) by blocking G1/S transition. Cell cycle-arrested parasites enter a quiescent G0-like state but, upon addition of exogenous polyamines, re-initiate their cell cycle. This ability to halt malaria parasites at a specific point in their cell cycle, and to subsequently trigger re-entry into the cell cycle, provides a valuable framework to investigate cell cycle regulation in these parasites. We subsequently used gene expression analyses to show that re-entry into the cell cycle involves expression of Ca2+-sensitive (cdpk4 and pk2) and mitotic kinases (nima and ark2), with deregulation of the pre-replicative complex associated with expression of pk2. Changes in gene expression could be driven through transcription factors MYB1 and two ApiAP2 family members. This new approach to parasite synchronisation therefore expands our currently limited toolkit to investigate cell cycle regulation in malaria parasites.
Collapse
|
19
|
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.
Collapse
Affiliation(s)
- Margaret A Phillips
- From the Departments of Biochemistry and Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390-9038
| |
Collapse
|
20
|
|
21
|
Turnbull LB, Siwo GH, Button-Simons KA, Tan A, Checkley LA, Painter HJ, Llinás M, Ferdig MT. Simultaneous genome-wide gene expression and transcript isoform profiling in the human malaria parasite. PLoS One 2017; 12:e0187595. [PMID: 29112986 PMCID: PMC5675406 DOI: 10.1371/journal.pone.0187595] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 10/23/2017] [Indexed: 12/22/2022] Open
Abstract
Gene expression DNA microarrays have been vital for characterizing whole-genome transcriptional profiles. Nevertheless, their effectiveness relies heavily on the accuracy of genome sequences, the annotation of gene structures, and the sequence-dependent performance of individual probes. Currently available gene expression arrays for the malaria parasite Plasmodium falciparum rely on an average of 2 probes per gene, usually positioned near the 3′ end of genes; consequently, existing designs are prone to measurement bias and cannot capture complexities such as the occurrence of transcript isoforms arising from alternative splicing or alternative start/ stop sites. Here, we describe two novel gene expression arrays with exon-focused probes designed with an average of 12 and 20 probes spanning each gene. This high probe density minimizes signal noise inherent in probe-to-probe sequence-dependent hybridization intensity. We demonstrate that these exon arrays accurately profile genome-wide expression, comparing favorably to currently available arrays and RNA-seq profiling, and can detect alternatively spliced transcript isoforms as well as non-coding RNAs (ncRNAs). Of the 964 candidate alternate splicing events from published RNA-seq studies, 162 are confirmed using the exon array. Furthermore, the exon array predicted 330 previously unidentified alternate splicing events. Gene expression microarrays continue to offer a cost-effective alternative to RNA-seq for the simultaneous monitoring of gene expression and alternative splicing events. Microarrays may even be preferred in some cases due to their affordability and the rapid turn-around of results when hundreds of samples are required for fine-scale systems biology investigations, including the monitoring of the networks of gene co-expression in the emergence of drug resistance.
Collapse
Affiliation(s)
- Lindsey B. Turnbull
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
- Ryan White Center for Pediatric Infectious Diseases and Global Health, Indiana University, Indianapolis, Indiana, United States of America
| | - Geoffrey H. Siwo
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
- IBM Research Africa, Johannesburg, South Africa
| | - Katrina A. Button-Simons
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Asako Tan
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
- Illumina, Madison, Wisconsin, United States of America
| | - Lisa A. Checkley
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Heather J. Painter
- Department of Biochemistry & Molecular Biology and Center for Malaria Research, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Manuel Llinás
- Department of Biochemistry & Molecular Biology and Center for Malaria Research, Pennsylvania State University, University Park, Pennsylvania, United States of America
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Michael T. Ferdig
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
- * E-mail:
| |
Collapse
|
22
|
Gevrekci AÖ. The roles of polyamines in microorganisms. World J Microbiol Biotechnol 2017; 33:204. [PMID: 29080149 DOI: 10.1007/s11274-017-2370-y] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 10/15/2017] [Indexed: 10/18/2022]
Abstract
Polyamines are small polycations that are well conserved in all the living organisms except Archae, Methanobacteriales and Halobacteriales. The most common polyamines are putrescine, spermidine and spermine, which exist in varying concentrations in different organisms. They are involved in a variety of cellular processes such as gene expression, cell growth, survival, stress response and proliferation. Therefore, diverse regulatory pathways are evolved to ensure strict regulation of polyamine concentration in the cells. Polyamine levels are kept under strict control by biosynthetic pathways as well as cellular uptake driven by specific transporters. Reverse genetic studies in microorganisms showed that deletion of the genes in polyamine metabolic pathways or depletion of polyamines have negative effects on cell survival and proliferation. The protein products of these genes are also used as drug targets against pathogenic protozoa. These altogether confirm the significant roles of polyamines in the cells. This mini-review focuses on the differential concentrations of polyamines and their cellular functions in different microorganisms. This will provide an insight about the diverse evolution of polyamine metabolism and function based on the physiology and the ecological context of the microorganisms.
Collapse
Affiliation(s)
- Aslıhan Örs Gevrekci
- Department of Psychology, Faculty of Science and Letters, Başkent University, Ankara, Turkey.
| |
Collapse
|
23
|
Metabolomics-Based Screening of the Malaria Box Reveals both Novel and Established Mechanisms of Action. Antimicrob Agents Chemother 2016; 60:6650-6663. [PMID: 27572396 DOI: 10.1128/aac.01226-16] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 08/16/2016] [Indexed: 12/22/2022] Open
Abstract
High-throughput phenotypic screening of chemical libraries has resulted in the identification of thousands of compounds with potent antimalarial activity, although in most cases, the mechanism(s) of action of these compounds remains unknown. Here we have investigated the mode of action of 90 antimalarial compounds derived from the Malaria Box collection using high-coverage, untargeted metabolomics analysis. Approximately half of the tested compounds induced significant metabolic perturbations in in vitro cultures of Plasmodium falciparum In most cases, the metabolic profiles were highly correlated with known antimalarials, in particular artemisinin, the 4-aminoquinolines, or atovaquone. Select Malaria Box compounds also induced changes in intermediates in essential metabolic pathways, such as isoprenoid biosynthesis (i.e., 2-C-methyl-d-erythritol 2,4-cyclodiphosphate) and linolenic acid metabolism (i.e., traumatic acid). This study provides a comprehensive database of the metabolic perturbations induced by chemically diverse inhibitors and highlights the utility of metabolomics for triaging new lead compounds and defining specific modes of action, which will assist with the development and optimization of new antimalarial drugs.
Collapse
|
24
|
Edwards RL, Odom John AR. Muddled mechanisms: recent progress towards antimalarial target identification. F1000Res 2016; 5:2514. [PMID: 27803804 PMCID: PMC5070598 DOI: 10.12688/f1000research.9477.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/06/2016] [Indexed: 01/06/2023] Open
Abstract
In the past decade, malaria rates have plummeted as a result of aggressive infection control measures and the adoption of artemisinin-based combination therapies (ACTs). However, a potential crisis looms ahead. Treatment failures to standard antimalarial regimens have been reported in Southeast Asia, and devastating consequences are expected if resistance spreads to the African continent. To prevent a potential public health emergency, the antimalarial arsenal must contain therapeutics with novel mechanisms of action (MOA). An impressive number of high-throughput screening (HTS) campaigns have since been launched, identifying thousands of compounds with activity against one of the causative agents of malaria,
Plasmodium falciparum. Now begins the difficult task of target identification, for which studies are often tedious, labor intensive, and difficult to interpret. In this review, we highlight approaches that have been instrumental in tackling the challenges of target assignment and elucidation of the MOA for hit compounds. Studies that apply these innovative techniques to antimalarial target identification are described, as well as the impact of the data in the field.
Collapse
Affiliation(s)
- Rachel L Edwards
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA
| | - Audrey R Odom John
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA; Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
| |
Collapse
|
25
|
Lima WR, Tessarin-Almeida G, Rozanski A, Parreira KS, Moraes MS, Martins DC, Hashimoto RF, Galante PAF, Garcia CRS. Signaling transcript profile of the asexual intraerythrocytic development cycle of Plasmodium falciparum induced by melatonin and cAMP. Genes Cancer 2016; 7:323-339. [PMID: 28050233 PMCID: PMC5115173 DOI: 10.18632/genesandcancer.118] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
According to the World Health Organization (WHO), Plasmodium falciparum is the deadliest parasite among all species. This parasite possesses the ability to sense molecules, including melatonin (MEL) and cAMP, and modulate its cell cycle accordingly. MEL synchronizes the development of this malaria parasite by activating several cascades, including the generation of the second messenger cAMP. Therefore, we performed RNA sequencing (RNA-Seq) analysis in P. falciparum erythrocytic stages (ring, trophozoite and schizont) treated with MEL and cAMP. To investigate the expression profile of P. falciparum genes regulated by MEL and cAMP, we performed RNA-Seq analysis in three P. falciparum strains (control, 3D7; protein kinase 7 knockout, PfPK7-; and PfPK7 complement, PfPK7C). In the 3D7 strain, 38 genes were differentially expressed upon MEL treatment; however, none of the genes in the trophozoite (T) stage PfPK7- knockout parasites were differentially expressed upon MEL treatment for 5 hours compared to untreated controls, suggesting that PfPK7 may be involved in the signaling leading to differential gene expression. Moreover, we found that MEL modified the mRNA expression of genes encoding membrane proteins, zinc ion-binding proteins and nucleic acid-binding proteins, which might influence numerous functions in the parasite. The RNA-Seq data following treatment with cAMP show that this molecule modulates different genes throughout the intraerythrocytic cycle, namely, 75, 101 and 141 genes, respectively, in the ring (R), T and schizont (S) stages. Our results highlight P. falciparum's perception of the external milieu through the signaling molecules MEL and cAMP, which are able to drive to changes in gene expression in the parasite.
Collapse
Affiliation(s)
- Wânia Rezende Lima
- Departamento de Fisiologia, Instituto de Biociências, Universidade de Sao Paulo, Sao Paulo, Brazil.,Instituto de Ciências Exatas e Naturais (ICEN)- Medicina, Universidade Federal do Mato Grosso - Campus Rondonópolis, Brazil
| | | | - Andrei Rozanski
- Centro de Oncologia Molecular, Hospital Sírio-Libanês, Sao Paulo, Brazil
| | - Kleber S Parreira
- Departamento de Imunologia e Parasitologia, Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Brazil
| | - Miriam S Moraes
- Departamento de Fisiologia, Instituto de Biociências, Universidade de Sao Paulo, Sao Paulo, Brazil
| | - David C Martins
- Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, São Paulo, Brazil
| | - Ronaldo F Hashimoto
- Departamento de Ciência da Computação, Instituto de Matemática e Estatística, Universidade de São Paulo, São Paulo, Brazil
| | - Pedro A F Galante
- Centro de Oncologia Molecular, Hospital Sírio-Libanês, Sao Paulo, Brazil
| | - Célia R S Garcia
- Departamento de Fisiologia, Instituto de Biociências, Universidade de Sao Paulo, Sao Paulo, Brazil
| |
Collapse
|
26
|
Pretzel J, Gehr M, Eisenkolb M, Wang L, Fritz-Wolf K, Rahlfs S, Becker K, Jortzik E. Characterization and redox regulation of Plasmodium falciparum methionine adenosyltransferase. J Biochem 2016; 160:355-367. [PMID: 27466371 DOI: 10.1093/jb/mvw045] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 06/14/2016] [Indexed: 11/12/2022] Open
Abstract
As a methyl group donor for biochemical reactions, S-adenosylmethionine plays a central metabolic role in most organisms. Depletion of S-adenosylmethionine has downstream effects on polyamine metabolism and methylation reactions, and is an effective way to combat pathogenic microorganisms such as malaria parasites. Inhibition of both the methylation cycle and polyamine synthesis strongly affects Plasmodium falciparum growth. Despite its central position in the methylation cycle, not much is currently known about P. falciparum methionine adenosyltransferase (PfalMAT). Notably, however, PfalMAT has been discussed as a target of different redox regulatory modifications. Modulating the redox state of critical cysteine residues is a way to regulate enzyme activity in different pathways in response to changes in the cellular redox state. In the present study, we optimized an assay for detailed characterization of enzymatic activity and redox regulation of PfalMAT. While the presence of reduced thioredoxin increases the activity of the enzyme, it was found to be inhibited upon S-glutathionylation and S-nitrosylation. A homology model and site-directed mutagenesis studies revealed a contribution of the residues Cys52, Cys113 and Cys187 to redox regulation of PfalMAT by influencing its structure and activity. This phenomenon connects cellular S-adenosylmethionine synthesis to the redox state of PfalMAT and therefore to the cellular redox homeostasis.
Collapse
Affiliation(s)
- Jette Pretzel
- Biochemistry and Molecular Biology, Justus Liebig University Giessen, Germany
| | - Marina Gehr
- Biochemistry and Molecular Biology, Justus Liebig University Giessen, Germany
| | - Maike Eisenkolb
- Biochemistry and Molecular Biology, Justus Liebig University Giessen, Germany
| | - Lihui Wang
- Biochemistry and Molecular Biology, Justus Liebig University Giessen, Germany
| | - Karin Fritz-Wolf
- Biochemistry and Molecular Biology, Justus Liebig University Giessen, Germany
| | - Stefan Rahlfs
- Biochemistry and Molecular Biology, Justus Liebig University Giessen, Germany
| | - Katja Becker
- Biochemistry and Molecular Biology, Justus Liebig University Giessen, Germany
| | - Esther Jortzik
- Biochemistry and Molecular Biology, Justus Liebig University Giessen, Germany
| |
Collapse
|
27
|
Siwo GH, Smith RS, Tan A, Button-Simons KA, Checkley LA, Ferdig MT. An integrative analysis of small molecule transcriptional responses in the human malaria parasite Plasmodium falciparum. BMC Genomics 2015; 16:1030. [PMID: 26637195 PMCID: PMC4670519 DOI: 10.1186/s12864-015-2165-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 10/29/2015] [Indexed: 12/05/2022] Open
Abstract
Background Transcriptional responses to small molecules can provide insights into drug mode of action (MOA). The capacity of the human malaria parasite, Plasmodium falciparum, to respond specifically to transcriptional perturbations has been unclear based on past approaches. Here, we present the most extensive profiling to date of the parasite’s transcriptional responsiveness to thirty-one chemically and functionally diverse small molecules. Methods We exposed two laboratory strains of the human malaria parasite P. falciparum to brief treatments of thirty-one chemically and functionally diverse small molecules associated with biological effects across multiple pathways based on various levels of evidence. We investigated the impact of chemical composition and MOA on gene expression similarities that arise between perturbations by various compounds. To determine the target biological pathways for each small molecule, we developed a novel framework for encoding small molecule effects on a spectra of biological processes or GO functions that are enriched in the differentially expressed genes of a given small molecule perturbation. Results We find that small molecules associated with similar transcriptional responses contain similar chemical features, and/ or have a shared MOA. The approach also revealed complex relationships between drugs and biological pathways that are missed by most exisiting approaches. For example, the approach was able to partition small molecule responses into drug-specific effects versus non-specific effects. Conclusions Our work provides a new framework for linking transcriptional responses to drug MOA in P. falciparum and can be generalized for the same purpose in other organisms. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2165-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Geoffrey H Siwo
- Eck Institute for Global Health, Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA.,Current Address: IBM TJ Watson Research Center, Yorktown Heights, NY, 10598, USA.,Current Address: IBM Research-Africa, South Africa Lab, Sandton, Johannesburg, 2196, South Africa
| | - Roger S Smith
- Eck Institute for Global Health, Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA.,Current Address: Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Asako Tan
- Eck Institute for Global Health, Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA.,Epicenter, Madison, WI, 53719, USA
| | - Katrina A Button-Simons
- Eck Institute for Global Health, Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Lisa A Checkley
- Eck Institute for Global Health, Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Michael T Ferdig
- Eck Institute for Global Health, Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA.
| |
Collapse
|
28
|
Screening of potential targets in Plasmodium falciparum using stage-specific metabolic network analysis. Mol Divers 2015; 19:991-1002. [PMID: 26303382 DOI: 10.1007/s11030-015-9632-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 08/12/2015] [Indexed: 01/29/2023]
Abstract
The Apicomplexa parasite Plasmodium is a major cause of death in developing countries which are less equipped to bring new medicines to the market. Currently available drugs used for treatment of malaria are limited either by inadequate efficacy, toxicity and/or increased resistance. Availability of the genome sequence, microarray data and metabolic profile of Plasmodium parasite offers an opportunity for the identification of stage-specific genes important to the organism's lifecycle. In this study, microarray data were analysed for differential expression and overlapped onto metabolic pathways to identify differentially regulated pathways essential for transition to successive erythrocytic stages. The results obtained indicate that S-adenosylmethionine decarboxylase/ornithine decarboxylase, a bifunctional enzyme required for polyamine synthesis, is important for the Plasmodium cell growth in the absence of exogenous polyamines. S-adenosylmethionine decarboxylase/ornithine decarboxylase is a valuable target for designing therapeutically useful inhibitors. One such inhibitor, [Formula: see text]-difluoromethyl ornithine, is currently in use for the treatment of African sleeping sickness caused by Trypanosoma brucei. Structural studies of ornithine decarboxylase along with known inhibitors and their analogues were carried out to screen drug databases for more effective and less toxic compounds.
Collapse
|
29
|
Cobbold SA, Chua HH, Nijagal B, Creek DJ, Ralph SA, McConville MJ. Metabolic Dysregulation Induced in Plasmodium falciparum by Dihydroartemisinin and Other Front-Line Antimalarial Drugs. J Infect Dis 2015; 213:276-86. [PMID: 26150544 DOI: 10.1093/infdis/jiv372] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 06/26/2015] [Indexed: 01/02/2023] Open
Abstract
Detailed information on the mode of action of antimalarial drugs can be used to improve existing drugs, identify new drug targets, and understand the basis of drug resistance. In this study we describe the use of a time-resolved, mass spectrometry (MS)-based metabolite profiling approach to map the metabolic perturbations induced by a panel of clinical antimalarial drugs and inhibitors on Plasmodium falciparum asexual blood stages. Drug-induced changes in metabolite levels in P. falciparum-infected erythrocytes were monitored over time using gas chromatography-MS and liquid chromatography-MS and changes in specific metabolic fluxes confirmed by nonstationary [(13)C]-glucose labeling. Dihydroartemisinin (DHA) was found to disrupt hemoglobin catabolism within 1 hour of exposure, resulting in a transient decrease in hemoglobin-derived peptides. Unexpectedly, it also disrupted pyrimidine biosynthesis, resulting in increased [(13)C]-glucose flux toward malate production, potentially explaining the susceptibility of P. falciparum to DHA during early blood-stage development. Unique metabolic signatures were also found for atovaquone, chloroquine, proguanil, cycloguanil and methylene blue. We also show that this approach can be used to identify the mode of action of novel antimalarials, such as the compound Torin 2, which inhibits hemoglobin catabolism.
Collapse
Affiliation(s)
| | - Hwa H Chua
- Department of Biochemistry and Molecular Biology
| | - Brunda Nijagal
- Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne
| | - Darren J Creek
- Department of Biochemistry and Molecular Biology Drug Delivery Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | | | - Malcolm J McConville
- Department of Biochemistry and Molecular Biology Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne
| |
Collapse
|
30
|
Fang X, Reifman J, Wallqvist A. Modeling metabolism and stage-specific growth of Plasmodium falciparum HB3 during the intraerythrocytic developmental cycle. MOLECULAR BIOSYSTEMS 2015; 10:2526-37. [PMID: 25001103 DOI: 10.1039/c4mb00115j] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The human malaria parasite Plasmodium falciparum goes through a complex life cycle, including a roughly 48-hour-long intraerythrocytic developmental cycle (IDC) in human red blood cells. A better understanding of the metabolic processes required during the asexual blood-stage reproduction will enhance our basic knowledge of P. falciparum and help identify critical metabolic reactions and pathways associated with blood-stage malaria. We developed a metabolic network model that mechanistically links time-dependent gene expression, metabolism, and stage-specific growth, allowing us to predict the metabolic fluxes, the biomass production rates, and the timing of production of the different biomass components during the IDC. We predicted time- and stage-specific production of precursors and macromolecules for P. falciparum (strain HB3), allowing us to link specific metabolites to specific physiological functions. For example, we hypothesized that coenzyme A might be involved in late-IDC DNA replication and cell division. Moreover, the predicted ATP metabolism indicated that energy was mainly produced from glycolysis and utilized for non-metabolic processes. Finally, we used the model to classify the entire tricarboxylic acid cycle into segments, each with a distinct function, such as superoxide detoxification, glutamate/glutamine processing, and metabolism of fumarate as a byproduct of purine biosynthesis. By capturing the normal metabolic and growth progression in P. falciparum during the IDC, our model provides a starting point for further elucidation of strain-specific metabolic activity, host-parasite interactions, stress-induced metabolic responses, and metabolic responses to antimalarial drugs and drug candidates.
Collapse
Affiliation(s)
- Xin Fang
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Ft. Detrick, MD 21702, USA.
| | | | | |
Collapse
|
31
|
Morphological and Molecular Descriptors of the Developmental Cycle of Babesia divergens Parasites in Human Erythrocytes. PLoS Negl Trop Dis 2015; 9:e0003711. [PMID: 25955414 PMCID: PMC4425553 DOI: 10.1371/journal.pntd.0003711] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 03/19/2015] [Indexed: 11/19/2022] Open
Abstract
Human babesiosis, especially caused by the cattle derived Babesia divergens parasite, is on the increase, resulting in renewed attentiveness to this potentially life threatening emerging zoonotic disease. The molecular mechanisms underlying the pathophysiology and intra-erythrocytic development of these parasites are poorly understood. This impedes concerted efforts aimed at the discovery of novel anti-babesiacidal agents. By applying sensitive cell biological and molecular functional genomics tools, we describe the intra-erythrocytic development cycle of B. divergens parasites from immature, mono-nucleated ring forms to bi-nucleated paired piriforms and ultimately multi-nucleated tetrads that characterizes zoonotic Babesia spp. This is further correlated for the first time to nuclear content increases during intra-erythrocytic development progression, providing insight into the part of the life cycle that occurs during human infection. High-content temporal evaluation elucidated the contribution of the different stages to life cycle progression. Moreover, molecular descriptors indicate that B. divergens parasites employ physiological adaptation to in vitro cultivation. Additionally, differential expression is observed as the parasite equilibrates its developmental stages during its life cycle. Together, this information provides the first temporal evaluation of the functional transcriptome of B. divergens parasites, information that could be useful in identifying biological processes essential to parasite survival for future anti-babesiacidal discoveries.
Collapse
|
32
|
Design and synthesis of a series of truncated neplanocin fleximers. Molecules 2014; 19:21200-14. [PMID: 25521119 PMCID: PMC6270936 DOI: 10.3390/molecules191221200] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 12/08/2014] [Accepted: 12/09/2014] [Indexed: 01/15/2023] Open
Abstract
In an effort to study the effects of flexibility on enzyme recognition and activity, we have developed several different series of flexible nucleoside analogues in which the purine base is split into its respective imidazole and pyrimidine components. The focus of this particular study was to synthesize the truncated neplanocin A fleximers to investigate their potential anti-protozoan activities by inhibition of S-adenosylhomocysteine hydrolase (SAHase). The three fleximers tested displayed poor anti-trypanocidal activities, with EC50 values around 200 μM. Further studies of the corresponding ribose fleximers, most closely related to the natural nucleoside substrates, revealed low affinity for the known T. brucei nucleoside transporters P1 and P2, which may be the reason for the lack of trypanocidal activity observed.
Collapse
|
33
|
Vincent IM, Barrett MP. Metabolomic-based strategies for anti-parasite drug discovery. ACTA ACUST UNITED AC 2014; 20:44-55. [PMID: 25281738 DOI: 10.1177/1087057114551519] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Metabolomics-based studies are proving of great utility in the analysis of modes of action (MOAs) and resistance mechanisms of drugs in parasitic protozoa. They have helped to determine the MOA of eflornithine, half of the gold standard combination therapy in use against human African trypanosomiasis (HAT), as well as the mechanism of resistance to this drug. In Leishmania, metabolomics has also given insight into the MOA of miltefosine, an alkylphospholipid. Several studies on antimony resistance in Leishmania have been conducted, analyzing the metabolic content of resistant lines, offering clues as to the MOA of this class of drugs. A study of chloroquine resistance in Plasmodium falciparum combined metabolomics techniques with other genetic and proteomic techniques to offer new insight into the role of the PfCRT protein. The MOA and mechanism of resistance to a group of halogenated pyrimidines in Trypanosoma brucei have also recently been elucidated. Effective as metabolomics techniques are, care must be taken in the design and implementation of these experiments, to ensure the resulting data are meaningful. This review outlines the steps required to conduct a metabolomics experiment as well as provide an overview of metabolomics-based drug research in protozoa to date.
Collapse
Affiliation(s)
- Isabel M Vincent
- The Glasgow Polyomics Facility and Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, UK
| | - Michael P Barrett
- The Glasgow Polyomics Facility and Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, UK
| |
Collapse
|
34
|
Vitamin B6-dependent enzymes in the human malaria parasite Plasmodium falciparum: a druggable target? BIOMED RESEARCH INTERNATIONAL 2014; 2014:108516. [PMID: 24524072 PMCID: PMC3912857 DOI: 10.1155/2014/108516] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 10/24/2013] [Accepted: 11/28/2013] [Indexed: 11/17/2022]
Abstract
Malaria is a deadly infectious disease which affects millions of people each year in tropical regions. There is no effective vaccine available and the treatment is based on drugs which are currently facing an emergence of drug resistance and in this sense the search for new drug targets is indispensable. It is well established that vitamin biosynthetic pathways, such as the vitamin B6 de novo synthesis present in Plasmodium, are excellent drug targets. The active form of vitamin B6, pyridoxal 5-phosphate, is, besides its antioxidative properties, a cofactor for a variety of essential enzymes present in the malaria parasite which includes the ornithine decarboxylase (ODC, synthesis of polyamines), the aspartate aminotransferase (AspAT, involved in the protein biosynthesis), and the serine hydroxymethyltransferase (SHMT, a key enzyme within the folate metabolism).
Collapse
|
35
|
le Roux D, Burger PB, Niemand J, Grobler A, Urbán P, Fernàndez-Busquets X, Barker RH, Serrano AE, I Louw A, Birkholtz LM. Novel S-adenosyl-L-methionine decarboxylase inhibitors as potent antiproliferative agents against intraerythrocytic Plasmodium falciparum parasites. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2013; 4:28-36. [PMID: 24596666 PMCID: PMC3940083 DOI: 10.1016/j.ijpddr.2013.11.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 11/19/2013] [Accepted: 11/20/2013] [Indexed: 12/31/2022]
Abstract
S-adenosyl-l-methionine decarboxylase (AdoMetDC) in the polyamine biosynthesis pathway has been identified as a suitable drug target in Plasmodium falciparum parasites, which causes the most lethal form of malaria. Derivatives of an irreversible inhibitor of this enzyme, 5'-{[(Z)-4-amino-2-butenyl]methylamino}-5'-deoxyadenosine (MDL73811), have been developed with improved pharmacokinetic profiles and activity against related parasites, Trypanosoma brucei. Here, these derivatives were assayed for inhibition of AdoMetDC from P. falciparum parasites and the methylated derivative, 8-methyl-5'-{[(Z)-4-aminobut-2-enyl]methylamino}-5'-deoxyadenosine (Genz-644131) was shown to be the most active. The in vitro efficacy of Genz-644131 was markedly increased by nanoencapsulation in immunoliposomes, which specifically targeted intraerythrocytic P. falciparum parasites.
Collapse
Affiliation(s)
- Dina le Roux
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Pieter B Burger
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Jandeli Niemand
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Anne Grobler
- DST/NWU Preclinical Drug Development Platform, North-West University, Potchefstroom 2531, South Africa
| | - Patricia Urbán
- Nanobioengineering Group, Institute for Bioengineering of Catalonia, Baldiri Reixac 10-12, Barcelona E08028, Spain ; Barcelona Centre for International Health Research (CRESIB), Hospital Clínic-Universitat de Barcelona, Rosselló 149-153, Barcelona E08036, Spain ; Biomolecular Interactions Team, Nanoscience and Nanotechnology Institute (IN2UB), University of Barcelona, Martí i Franquès 1, Barcelona E08028, Spain
| | - Xavier Fernàndez-Busquets
- Nanobioengineering Group, Institute for Bioengineering of Catalonia, Baldiri Reixac 10-12, Barcelona E08028, Spain ; Barcelona Centre for International Health Research (CRESIB), Hospital Clínic-Universitat de Barcelona, Rosselló 149-153, Barcelona E08036, Spain ; Biomolecular Interactions Team, Nanoscience and Nanotechnology Institute (IN2UB), University of Barcelona, Martí i Franquès 1, Barcelona E08028, Spain
| | - Robert H Barker
- Genzyme Corporation, 153 Second Avenue, Waltham, MA 02451, USA
| | - Adelfa E Serrano
- University of Puerto Rico-School of Medicine, Department of Microbiology and Medical Zoology, P.O. Box 365067, San Juan PR 00936-5067, Puerto Rico
| | - Abraham I Louw
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| |
Collapse
|
36
|
Abstract
The discovery, development and optimal utilization of pharmaceuticals can be greatly enhanced by knowledge of their modes of action. However, many drugs currently on the market act by unknown mechanisms. Untargeted metabolomics offers the potential to discover modes of action for drugs that perturb cellular metabolism. Development of high resolution LC-MS methods and improved data analysis software now allows rapid detection of drug-induced changes to cellular metabolism in an untargeted manner. Several studies have demonstrated the ability of untargeted metabolomics to provide unbiased target discovery for antimicrobial drugs, in particular for antiprotozoal agents. Furthermore, the utilization of targeted metabolomics techniques has enabled validation of existing hypotheses regarding antiprotozoal drug mechanisms. Metabolomics approaches are likely to assist with optimization of new drug candidates by identification of drug targets, and by allowing detailed characterization of modes of action and resistance of existing and novel antiprotozoal drugs.
Collapse
|
37
|
Oehring SC, Woodcroft BJ, Moes S, Wetzel J, Dietz O, Pulfer A, Dekiwadia C, Maeser P, Flueck C, Witmer K, Brancucci NMB, Niederwieser I, Jenoe P, Ralph SA, Voss TS. Organellar proteomics reveals hundreds of novel nuclear proteins in the malaria parasite Plasmodium falciparum. Genome Biol 2012. [PMID: 23181666 PMCID: PMC4053738 DOI: 10.1186/gb-2012-13-11-r108] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND The post-genomic era of malaria research provided unprecedented insights into the biology of Plasmodium parasites. Due to the large evolutionary distance to model eukaryotes, however, we lack a profound understanding of many processes in Plasmodium biology. One example is the cell nucleus, which controls the parasite genome in a development- and cell cycle-specific manner through mostly unknown mechanisms. To study this important organelle in detail, we conducted an integrative analysis of the P. falciparum nuclear proteome. RESULTS We combined high accuracy mass spectrometry and bioinformatic approaches to present for the first time an experimentally determined core nuclear proteome for P. falciparum. Besides a large number of factors implicated in known nuclear processes, one-third of all detected proteins carry no functional annotation, including many phylum- or genus-specific factors. Importantly, extensive experimental validation using 30 transgenic cell lines confirmed the high specificity of this inventory, and revealed distinct nuclear localization patterns of hitherto uncharacterized proteins. Further, our detailed analysis identified novel protein domains potentially implicated in gene transcription pathways, and sheds important new light on nuclear compartments and processes including regulatory complexes, the nucleolus, nuclear pores, and nuclear import pathways. CONCLUSION Our study provides comprehensive new insight into the biology of the Plasmodium nucleus and will serve as an important platform for dissecting general and parasite-specific nuclear processes in malaria parasites. Moreover, as the first nuclear proteome characterized in any protist organism, it will provide an important resource for studying evolutionary aspects of nuclear biology.
Collapse
|
38
|
Bazzani S, Hoppe A, Holzhütter HG. Network-based assessment of the selectivity of metabolic drug targets in Plasmodium falciparum with respect to human liver metabolism. BMC SYSTEMS BIOLOGY 2012; 6:118. [PMID: 22937810 PMCID: PMC3543272 DOI: 10.1186/1752-0509-6-118] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Accepted: 07/23/2012] [Indexed: 11/10/2022]
Abstract
Background The search for new drug targets for antibiotics against Plasmodium falciparum, a major cause of human deaths, is a pressing scientific issue, as multiple resistance strains spread rapidly. Metabolic network-based analyses may help to identify those parasite’s essential enzymes whose homologous counterparts in the human host cells are either absent, non-essential or relatively less essential. Results Using the well-curated metabolic networks PlasmoNet of the parasite Plasmodium falciparum and HepatoNet1 of the human hepatocyte, the selectivity of 48 experimental antimalarial drug targets was analyzed. Applying in silico gene deletions, 24 of these drug targets were found to be perfectly selective, in that they were essential for the parasite but non-essential for the human cell. The selectivity of a subset of enzymes, that were essential in both models, was evaluated with the reduced fitness concept. It was, then, possible to quantify the reduction in functional fitness of the two networks under the progressive inhibition of the same enzymatic activity. Overall, this in silico analysis provided a selectivity ranking that was in line with numerous in vivo and in vitro observations. Conclusions Genome-scale models can be useful to depict and quantify the effects of enzymatic inhibitions on the impaired production of biomass components. From the perspective of a host-pathogen metabolic interaction, an estimation of the drug targets-induced consequences can be beneficial for the development of a selective anti-parasitic drug.
Collapse
Affiliation(s)
- Susanna Bazzani
- Institut für Biochemie, Charite-Universitätsmedizin, Berlin, Germany.
| | | | | |
Collapse
|
39
|
Niemand J, Louw AI, Birkholtz L, Kirk K. Polyamine uptake by the intraerythrocytic malaria parasite, Plasmodium falciparum. Int J Parasitol 2012; 42:921-9. [PMID: 22878129 DOI: 10.1016/j.ijpara.2012.07.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Revised: 07/21/2012] [Accepted: 07/23/2012] [Indexed: 11/26/2022]
Abstract
Polyamines and the enzymes involved in their biosynthesis are present at high levels in rapidly proliferating cells, including cancer cells and protozoan parasites. Inhibition of polyamine biosynthesis in asexual blood-stage malaria parasites causes cytostatic arrest of parasite development under in vitro conditions, but does not cure infections in vivo. This may be due to replenishment of the parasite's intracellular polyamine pool via salvage of exogenous polyamines from the host. However, the mechanism(s) of polyamine uptake by the intraerythrocytic parasite are not well understood. In this study, the uptake of the polyamines, putrescine and spermidine, into Plasmodium falciparum parasites functionally isolated from their host erythrocyte was investigated using radioisotope flux techniques. Both putrescine and spermidine were taken up into isolated parasites via a temperature-dependent process that showed cross-competition between different polyamines. There was also some inhibition of polyamine uptake by basic amino acids. Inhibition of polyamine biosynthesis led to an increase in the total amount of putrescine and spermidine taken up from the extracellular medium. The uptake of putrescine and spermidine by isolated parasites was independent of extracellular Na(+) but increased with increasing external pH. Uptake also showed a marked dependence on the parasite's membrane potential, decreasing with membrane depolarization and increasing with membrane hyperpolarization. The data are consistent with polyamines being taken up into the parasite via an electrogenic uptake process, energised by the parasite's inwardly negative membrane potential.
Collapse
Affiliation(s)
- J Niemand
- Department of Biochemistry, Faculty of Natural and Agricultural Sciences, University of Pretoria, Hatfield 0028, South Africa
| | | | | | | |
Collapse
|
40
|
A quantitative liquid chromatography tandem mass spectrometry method for metabolomic analysis of Plasmodium falciparum lipid related metabolites. Anal Chim Acta 2012; 739:47-55. [PMID: 22819049 DOI: 10.1016/j.aca.2012.06.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Revised: 06/07/2012] [Accepted: 06/09/2012] [Indexed: 11/22/2022]
Abstract
Plasmodium falciparum is the causative agent of malaria, a deadly infectious disease for which treatments are scarce and drug-resistant parasites are now increasingly found. A comprehensive method of identifying and quantifying metabolites of this intracellular parasite could expand the arsenal of tools to understand its biology, and be used to develop new treatments against the disease. Here, we present two methods based on liquid chromatography tandem mass spectrometry for reliable measurement of water-soluble metabolites involved in phospholipid biosynthesis, as well as several other metabolites that reflect the metabolic status of the parasite including amino acids, carboxylic acids, energy-related carbohydrates, and nucleotides. A total of 35 compounds was quantified. In the first method, polar compounds were retained by hydrophilic interaction chromatography (amino column) and detected in negative mode using succinic acid-(13)C(4) and fluorovaline as internal standards. In the second method, separations were carried out using reverse phase (C18) ion-pair liquid chromatography, with heptafluorobutyric acid as a volatile ion pairing reagent in positive detection mode, using d(9)-choline and 4-aminobutanol as internal standards. Standard curves were performed in P. falciparum-infected and uninfected red blood cells using standard addition method (r(2)>0.99). The intra- and inter-day accuracy and precision as well as the extraction recovery of each compound were determined. The lower limit of quantitation varied from 50pmol to 100fmol/3×10(7)cells. These methods were validated and successfully applied to determine intracellular concentrations of metabolites from uninfected host RBCs and isolated Plasmodium parasites.
Collapse
|
41
|
Le Roch KG, Chung DWD, Ponts N. Genomics and integrated systems biology in Plasmodium falciparum: a path to malaria control and eradication. Parasite Immunol 2012; 34:50-60. [PMID: 21995286 DOI: 10.1111/j.1365-3024.2011.01340.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The first draft of the human malaria parasite's genome was released in 2002. Since then, the malaria scientific community has witnessed a steady embrace of new and powerful functional genomic studies. Over the years, these approaches have slowly revolutionized malaria research and enabled the comprehensive, unbiased investigation of various aspects of the parasite's biology. These genome-wide analyses delivered a refined annotation of the parasite's genome, delivered a better knowledge of its RNA, proteins and metabolite derivatives, and fostered the discovery of new vaccine and drug targets. Despite the positive impacts of these genomic studies, most research and investment still focus on protein targets, drugs and vaccine candidates that were known before the publication of the parasite genome sequence. However, recent access to next-generation sequencing technologies, along with an increased number of genome-wide applications, is expanding the impact of the parasite genome on biomedical research, contributing to a paradigm shift in research activities that may possibly lead to new optimized diagnosis and treatments. This review provides an update of Plasmodium falciparum genome sequences and an overview of the rapid development of genomics and system biology applications that have an immense potential of creating powerful tools for a successful malaria eradication campaign.
Collapse
Affiliation(s)
- K G Le Roch
- Department of Cell Biology and Neuroscience, University of California Riverside, Institute for Integrative Genome Biology, and Center for Disease Vector Research, Riverside, CA 92521, USA.
| | | | | |
Collapse
|
42
|
Vincent IM, Creek DJ, Burgess K, Woods DJ, Burchmore RJS, Barrett MP. Untargeted metabolomics reveals a lack of synergy between nifurtimox and eflornithine against Trypanosoma brucei. PLoS Negl Trop Dis 2012; 6:e1618. [PMID: 22563508 PMCID: PMC3341325 DOI: 10.1371/journal.pntd.0001618] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2012] [Accepted: 03/05/2012] [Indexed: 01/08/2023] Open
Abstract
A non-targeted metabolomics-based approach is presented that enables the study of pathways in response to drug action with the aim of defining the mode of action of trypanocides. Eflornithine, a polyamine pathway inhibitor, and nifurtimox, whose mode of action involves its metabolic activation, are currently used in combination as first line treatment against stage 2, CNS-involved, human African trypanosomiasis (HAT). Drug action was assessed using an LC-MS based non-targeted metabolomics approach. Eflornithine revealed the expected changes to the polyamine pathway as well as several unexpected changes that point to pathways and metabolites not previously described in bloodstream form trypanosomes, including a lack of arginase activity and N-acetylated ornithine and putrescine. Nifurtimox was shown to be converted to a trinitrile metabolite indicative of metabolic activation, as well as inducing changes in levels of metabolites involved in carbohydrate and nucleotide metabolism. However, eflornithine and nifurtimox failed to synergise anti-trypanosomal activity in vitro, and the metabolomic changes associated with the combination are the sum of those found in each monotherapy with no indication of additional effects. The study reveals how untargeted metabolomics can yield rapid information on drug targets that could be adapted to any pharmacological situation.
Collapse
Affiliation(s)
- Isabel M. Vincent
- The Wellcome Trust Centre for Molecular Parasitology, Institute for Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Darren J. Creek
- The Wellcome Trust Centre for Molecular Parasitology, Institute for Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Glasgow Polyomics Facility, University of Glasgow, Glasgow, United Kingdom
| | - Karl Burgess
- The Wellcome Trust Centre for Molecular Parasitology, Institute for Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Glasgow Polyomics Facility, University of Glasgow, Glasgow, United Kingdom
| | - Debra J. Woods
- Pfizer Animal Health, Pfizer Inc, Kalamazoo, Michigan, United States of America
| | - Richard J. S. Burchmore
- The Wellcome Trust Centre for Molecular Parasitology, Institute for Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Glasgow Polyomics Facility, University of Glasgow, Glasgow, United Kingdom
| | - Michael P. Barrett
- The Wellcome Trust Centre for Molecular Parasitology, Institute for Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Glasgow Polyomics Facility, University of Glasgow, Glasgow, United Kingdom
| |
Collapse
|
43
|
Olszewski KL, Llinás M. Extraction of hydrophilic metabolites from Plasmodium falciparum-infected erythrocytes for metabolomic analysis. Methods Mol Biol 2012; 923:259-66. [PMID: 22990783 DOI: 10.1007/978-1-62703-026-7_17] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Abstract
Metabolomics is an increasingly common analytical approach for investigating metabolic networks of pathogenic organisms. This may be of particular use in the study of parasitic infections due to the intrinsic metabolic connection between the parasite and its host. In vitro cultures of the malaria parasite Plasmodium falciparum present a valuable platform to elucidate the structure and dynamics of the parasite's metabolic network and to determine the mechanisms of action of antimalarial drugs and drug resistance mutations. Accurately measuring metabolite levels requires a reproducible method for quantifying intracellular metabolites. Here we present a simple protocol for extracting hydrophilic metabolites from P. falciparum-infected erythrocyte cultures.
Collapse
Affiliation(s)
- Kellen L Olszewski
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | | |
Collapse
|
44
|
Šečkutė J, McCloskey DE, Thomas HJ, Secrist JA, Pegg AE, Ealick SE. Binding and inhibition of human spermidine synthase by decarboxylated S-adenosylhomocysteine. Protein Sci 2011; 20:1836-44. [PMID: 21898642 PMCID: PMC3267948 DOI: 10.1002/pro.717] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Revised: 08/10/2011] [Accepted: 08/11/2011] [Indexed: 01/07/2023]
Abstract
Aminopropyltransferases are essential enzymes that form polyamines in eukaryotic and most prokaryotic cells. Spermidine synthase (SpdS) is one of the most well-studied enzymes in this biosynthetic pathway. The enzyme uses decarboxylated S-adenosylmethionine and a short-chain polyamine (putrescine) to make a medium-chain polyamine (spermidine) and 5'-deoxy-5'-methylthioadenosine as a byproduct. Here, we report a new spermidine synthase inhibitor, decarboxylated S-adenosylhomocysteine (dcSAH). The inhibitor was synthesized, and dose-dependent inhibition of human, Thermatoga maritima, and Plasmodium falciparum spermidine synthases, as well as functionally homologous human spermine synthase, was determined. The human SpdS/dcSAH complex structure was determined by X-ray crystallography at 2.0 Å resolution and showed consistent active site positioning and coordination with previously known structures. Isothermal calorimetry binding assays confirmed inhibitor binding to human SpdS with K(d) of 1.1 ± 0.3 μM in the absence of putrescine and 3.2 ± 0.1 μM in the presence of putrescine. These results indicate a potential for further inhibitor development based on the dcSAH scaffold.
Collapse
Affiliation(s)
- Jolita Šečkutė
- Department of Chemistry and Chemical Biology, Cornell UniversityIthaca, New York 14853
| | - Diane E McCloskey
- Department of Cellular and Molecular Physiology, Milton S. Hershey Medical Center, Pennsylvania State University College of MedicineHershey, Pennsylvania 17033,Department of Pharmacology, Milton S. Hershey Medical Center, Pennsylvania State University College of MedicineHershey, Pennsylvania 17033
| | | | | | - Anthony E Pegg
- Department of Cellular and Molecular Physiology, Milton S. Hershey Medical Center, Pennsylvania State University College of MedicineHershey, Pennsylvania 17033,Department of Pharmacology, Milton S. Hershey Medical Center, Pennsylvania State University College of MedicineHershey, Pennsylvania 17033
| | - Steven E Ealick
- Department of Chemistry and Chemical Biology, Cornell UniversityIthaca, New York 14853,*Correspondence to: Steven E. Ealick, 120 Baker Lab, Cornell University, Ithaca, NY 14853-1301. E-mail:
| |
Collapse
|
45
|
Becker JVW, van der Merwe MM, van Brummelen AC, Pillay P, Crampton BG, Mmutlane EM, Parkinson C, van Heerden FR, Crouch NR, Smith PJ, Mancama DT, Maharaj VJ. In vitro anti-plasmodial activity of Dicoma anomala subsp. gerrardii (Asteraceae): identification of its main active constituent, structure-activity relationship studies and gene expression profiling. Malar J 2011; 10:295. [PMID: 21985233 PMCID: PMC3200184 DOI: 10.1186/1475-2875-10-295] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 10/11/2011] [Indexed: 12/04/2022] Open
Abstract
Background Anti-malarial drug resistance threatens to undermine efforts to eliminate this deadly disease. The resulting omnipresent requirement for drugs with novel modes of action prompted a national consortium initiative to discover new anti-plasmodial agents from South African medicinal plants. One of the plants selected for investigation was Dicoma anomala subsp. gerrardii, based on its ethnomedicinal profile. Methods Standard phytochemical analysis techniques, including solvent-solvent extraction, thin-layer- and column chromatography, were used to isolate the main active constituent of Dicoma anomala subsp. gerrardii. The crystallized pure compound was identified using nuclear magnetic resonance spectroscopy, mass spectrometry and X-ray crystallography. The compound was tested in vitro on Plasmodium falciparum cultures using the parasite lactate dehydrogenase (pLDH) assay and was found to have anti-malarial activity. To determine the functional groups responsible for the activity, a small collection of synthetic analogues was generated - the aim being to vary features proposed as likely to be related to the anti-malarial activity and to quantify the effect of the modifications in vitro using the pLDH assay. The effects of the pure compound on the P. falciparum transcriptome were subsequently investigated by treating ring-stage parasites (alongside untreated controls), followed by oligonucleotide microarray- and data analysis. Results The main active constituent was identified as dehydrobrachylaenolide, a eudesmanolide-type sesquiterpene lactone. The compound demonstrated an in vitro IC50 of 1.865 μM against a chloroquine-sensitive strain (D10) of P. falciparum. Synthetic analogues of the compound confirmed an absolute requirement that the α-methylene lactone be present in the eudesmanolide before significant anti-malarial activity was observed. This feature is absent in the artemisinins and suggests a different mode of action. Microarray data analysis identified 572 unique genes that were differentially expressed as a result of the treatment and gene ontology analysis identified various biological processes and molecular functions that were significantly affected. Comparison of the dehydrobrachylaenolide treatment transcriptional dataset with a published artesunate (also a sesquiterpene lactone) dataset revealed little overlap. These results strengthen the notion that the isolated compound and the artemisinins have differentiated modes of action. Conclusions The novel mode of action of dehydrobrachylaenolide, detected during these studies, will play an ongoing role in advancing anti-plasmodial drug discovery efforts.
Collapse
|
46
|
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.
Collapse
|
47
|
Kritsiriwuthinan K, Chaotheing S, Shaw PJ, Wongsombat C, Chavalitshewinkoon-Petmitr P, Kamchonwongpaisan S. Global gene expression profiling of Plasmodium falciparum in response to the anti-malarial drug pyronaridine. Malar J 2011; 10:242. [PMID: 21849091 PMCID: PMC3224238 DOI: 10.1186/1475-2875-10-242] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Accepted: 08/18/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Pyronaridine (PN) and chloroquine (CQ) are structurally related anti-malarial drugs with primarily the same mode of action. However, PN is effective against several multidrug-resistant lines of Plasmodium falciparum, including CQ resistant lines, suggestive of important operational differences between the two drugs. METHODS Synchronized trophozoite stage cultures of P. falciparum strain K1 (CQ resistant) were exposed to 50% inhibitory concentrations (IC50) of PN and CQ, and parasites were harvested from culture after 4 and 24 hours exposure. Global transcriptional changes effected by drug treatment were investigated using DNA microarrays. RESULTS After a 4 h drug exposure, PN induced a greater degree of transcriptional perturbation (61 differentially expressed features) than CQ (10 features). More genes were found to respond to 24 h treatments with both drugs, and 461 features were found to be significantly responsive to one or both drugs across all treatment conditions. Filtering was employed to remove features unrelated to primary drug action, specifically features representing genes developmentally regulated, secondary stress/death related processes and sexual stage development. The only significant gene ontologies represented among the 46 remaining features after filtering relate to host exported proteins from multi-gene families. CONCLUSIONS The malaria parasite's molecular responses to PN and CQ treatment are similar in terms of the genes and pathways affected. However, PN appears to exert a more rapid response than CQ. The faster action of PN may explain why PN is more efficacious than CQ, particularly against CQ resistant isolates. In agreement with several other microarray studies of drug action on the parasite, it is not possible, however, to discern mechanism of drug action from the drug-responsive genes.
Collapse
Affiliation(s)
- Kanyanan Kritsiriwuthinan
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Pathumthani 12120, Thailand
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Sastra Chaotheing
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Pathumthani 12120, Thailand
| | - Philip J Shaw
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Pathumthani 12120, Thailand
| | - Chayaphat Wongsombat
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Pathumthani 12120, Thailand
| | | | - Sumalee Kamchonwongpaisan
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Pathumthani 12120, Thailand
| |
Collapse
|
48
|
Wu F, Christen P, Gehring H. A novel approach to inhibit intracellular vitamin B6‐dependent enzymes: proof of principle with human and plasmodium ornithine decarboxylase and human histidine decarboxylase. FASEB J 2011; 25:2109-22. [DOI: 10.1096/fj.10-174383] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Fang Wu
- Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Center for Systems BiomedicineShanghai Jiao Tong UniversityShanghaiChina
| | | | - Heinz Gehring
- Department of BiochemistryUniversity of ZurichZurichSwitzerland
| |
Collapse
|
49
|
van Brummlen T, Becker JVW, Mancama DT, Hoppe H. Investigating transcriptional regulation of Plasmodium falciparum upon drug perturbation. Malar J 2010. [PMCID: PMC2963241 DOI: 10.1186/1475-2875-9-s2-o32] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
50
|
Metabolomics and malaria biology. Mol Biochem Parasitol 2010; 175:104-11. [PMID: 20970461 DOI: 10.1016/j.molbiopara.2010.09.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Revised: 09/29/2010] [Accepted: 09/30/2010] [Indexed: 12/31/2022]
Abstract
Metabolomics has ushered in a novel and multi-disciplinary realm in biological research. It has provided researchers with a platform to combine powerful biochemical, statistical, computational, and bioinformatics techniques to delve into the mysteries of biology and disease. The application of metabolomics to study malaria parasites represents a major advance in our approach towards gaining a more comprehensive perspective on parasite biology and disease etiology. This review attempts to highlight some of the important aspects of the field of metabolomics, and its ongoing and potential future applications to malaria research.
Collapse
|