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Morales-Luna L, Vázquez-Bautista M, Martínez-Rosas V, Rojas-Alarcón MA, Ortega-Cuellar D, González-Valdez A, Pérez de la Cruz V, Arreguin-Espinosa R, Rodríguez-Bustamante E, Rodríguez-Flores E, Hernández-Ochoa B, Gómez-Manzo S. Fused Enzyme Glucose-6-Phosphate Dehydrogenase::6-Phosphogluconolactonase (G6PD::6PGL) as a Potential Drug Target in Giardia lamblia, Trichomonas vaginalis, and Plasmodium falciparum. Microorganisms 2024; 12:112. [PMID: 38257939 PMCID: PMC10819308 DOI: 10.3390/microorganisms12010112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 01/01/2024] [Accepted: 01/03/2024] [Indexed: 01/24/2024] Open
Abstract
Several microaerophilic parasites such as Giardia lamblia, Trichomonas vaginalis, and Plasmodium falciparum are major disease-causing organisms and are responsible for spreading infections worldwide. Despite significant progress made in understanding the metabolism and molecular biology of microaerophilic parasites, chemotherapeutic treatment to control it has seen limited progress. A current proposed strategy for drug discovery against parasitic diseases is the identification of essential key enzymes of metabolic pathways associated with the parasite's survival. In these organisms, glucose-6-phosphate dehydrogenase::6-phosphogluconolactonase (G6PD:: 6PGL), the first enzyme of the pentose phosphate pathway (PPP), is essential for its metabolism. Since G6PD:: 6PGL provides substrates for nucleotides synthesis and NADPH as a source of reducing equivalents, it could be considered an anti-parasite drug target. This review analyzes the anaerobic energy metabolism of G. lamblia, T. vaginalis, and P. falciparum, with a focus on glucose metabolism through the pentose phosphate pathway and the significance of the fused G6PD:: 6PGL enzyme as a therapeutic target in the search for new drugs.
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Affiliation(s)
- Laura Morales-Luna
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico; (L.M.-L.); (M.V.-B.); (V.M.-R.); (M.A.R.-A.)
- Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - Montserrat Vázquez-Bautista
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico; (L.M.-L.); (M.V.-B.); (V.M.-R.); (M.A.R.-A.)
- Programa de Posgrado en Biomedicina y Biotecnología Molecular, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City 11340, Mexico
| | - Víctor Martínez-Rosas
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico; (L.M.-L.); (M.V.-B.); (V.M.-R.); (M.A.R.-A.)
- Programa de Posgrado en Biomedicina y Biotecnología Molecular, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City 11340, Mexico
| | - Miriam Abigail Rojas-Alarcón
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico; (L.M.-L.); (M.V.-B.); (V.M.-R.); (M.A.R.-A.)
- Programa de Posgrado en Biomedicina y Biotecnología Molecular, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City 11340, Mexico
| | - Daniel Ortega-Cuellar
- Laboratorio de Nutrición Experimental, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico;
| | - Abigail González-Valdez
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico;
| | - Verónica Pérez de la Cruz
- Neurobiochemistry and Behavior Laboratory, National Institute of Neurology and Neurosurgery “Manuel Velasco Suárez”, Mexico City 14269, Mexico;
| | - Roberto Arreguin-Espinosa
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico; (R.A.-E.); (E.R.-B.); (E.R.-F.)
| | - Eduardo Rodríguez-Bustamante
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico; (R.A.-E.); (E.R.-B.); (E.R.-F.)
- Departamento de Bioingeniería, Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey, Monterrey 64849, Mexico
| | - Eden Rodríguez-Flores
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico; (R.A.-E.); (E.R.-B.); (E.R.-F.)
| | - Beatriz Hernández-Ochoa
- Laboratorio de Inmunoquímica, Hospital Infantil de México Federico Gómez, Secretaría de Salud, Mexico City 06720, Mexico
| | - Saúl Gómez-Manzo
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico; (L.M.-L.); (M.V.-B.); (V.M.-R.); (M.A.R.-A.)
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Paul A, Roy PK, Babu NK, Dhumal TT, Singh S. Leishmania donovani 6-phosphogluconolactonase: Crucial for growth and host infection? Microb Pathog 2023; 178:106082. [PMID: 36958644 DOI: 10.1016/j.micpath.2023.106082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 03/14/2023] [Accepted: 03/19/2023] [Indexed: 03/25/2023]
Abstract
The hexose monophosphate shunt is a crucial pathway in a variety of microorganisms owing to its vital metabolic products and intermediates such as NADPH, ribose 5-phosphate etc. The enzyme 6-phosphogluconolactonase catalyses the second step of this pathway, converting 6-phosphogluconolactone to 6-phosphogluconic acid. This enzyme has been known to have a significant involvement in growth, pathogenesis and sensitivity to oxidative stress in bacterial and protozoal pathogens. However, the functional role of kinetoplastid Leishmania donovani 6-phospohogluconolactonase (Ld6PGL) remains unexplored. L. donovani is the second largest parasitic killer and causative organism of life threatening visceral leishmaniasis. To understand its possible functional role in the parasite, the alleles of Ld6PGL were sequentially knocked-out followed by gene complementation. The Ld6PGL mutant cell lines showed decrease in transcriptional and translational expression as well as in the enzyme activity. In case of Ld6PGL null mutants, approximately 2-fold reduction was observed in growth. The null mutants also showed ∼38% decrease in infectivity, which recovered to ∼15% on complementation. Scanning electron microscopy showed a marked decrease in flagellar length in the knockout parasites. When treated with the standard drug miltefosine, the mutant strains had no significant change in the drug sensitivity. However, the Ld6PGL mutants were more susceptible to oxidative stress. Our findings suggest that 6PGL is required for parasite growth and infection but it is not essential.
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Affiliation(s)
- Anindita Paul
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, 160062, Punjab, India
| | - Pradyot Kumar Roy
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, 160062, Punjab, India
| | - Neerupudi Kishore Babu
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, 160062, Punjab, India
| | - Tushar Tukaram Dhumal
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, 160062, Punjab, India
| | - Sushma Singh
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, 160062, Punjab, India.
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Morales-Luna L, Hernández-Ochoa B, Martínez-Rosas V, Navarrete-Vázquez G, Ortega-Cuellar D, Rufino-González Y, González-Valdez A, Arreguin-Espinosa R, Franco-Vásquez AM, Pérez de la Cruz V, Enríquez-Flores S, Martínez-Conde C, Canseco-Ávila LM, Gómez-Chávez F, Gómez-Manzo S. Giardia lamblia G6PD::6PGL Fused Protein Inhibitors Decrease Trophozoite Viability: A New Alternative against Giardiasis. Int J Mol Sci 2022; 23:ijms232214358. [PMID: 36430836 PMCID: PMC9697976 DOI: 10.3390/ijms232214358] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 11/08/2022] [Accepted: 11/14/2022] [Indexed: 11/22/2022] Open
Abstract
Treatments to combat giardiasis have been reported to have several drawbacks, partly due to the drug resistance and toxicity of current antiparasitic agents. These constraints have prompted many researchers to investigate new drugs that act against protozoan parasites. Enzyme inhibition is an important means of regulating pathogen metabolism and has recently been identified as a significant alternative target in the search for new treatments. Glucose-6-phosphate dehydrogenase and 6-phosphogluconolactonase (G6PD::6PGL) is a bifunctional enzyme involved in the pentose phosphate pathway (PPP) in Giardia lamblia (G. lamblia). The G. lamblia enzyme is unusual since, unlike the human enzyme, it is a fused enzyme. Here, we show, through inhibition assays, that an in-house chemical library of 120 compounds and four target compounds, named CNZ-7, CNZ-8, CMC-1, and FLP-2, are potent inhibitors of the G. lamblia G6PD::6PGL fused enzyme. With a constant (k2) of 2.3, 3.2, and 2.8 M−1 s−1, respectively, they provoke alterations in the secondary and tertiary protein structure and global stability. As a novel approach, target compounds show antigiardial activity, with IC50 values of 8.7, 15.2, 15.3, and 24.1 µM in trophozoites from G. lamblia. Moreover, these compounds show selectivity against G. lamblia, since, through counter-screening in Caco-2 and HT29 human cells, they were found to have low toxicity. This finding positions these compounds as a potential and attractive starting point for new antigiardial drugs.
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Affiliation(s)
- Laura Morales-Luna
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico
- Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - Beatriz Hernández-Ochoa
- Laboratorio de Inmunoquímica, Hospital Infantil de México Federico Gómez, Secretaría de Salud, Mexico City 06720, Mexico
| | - Víctor Martínez-Rosas
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico
- Programa de Posgrado en Biomedicina y Biotecnología Molecular, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City 11340, Mexico
| | - Gabriel Navarrete-Vázquez
- Facultad de Farmacia, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Chamilpa, Cuernavaca 62209, Mexico
| | - Daniel Ortega-Cuellar
- Laboratorio de Nutrición Experimental, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico
| | - Yadira Rufino-González
- Laboratorio de Parasitología Experimental, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico
| | - Abigail González-Valdez
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - Roberto Arreguin-Espinosa
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - Adrián Marcelo Franco-Vásquez
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - Verónica Pérez de la Cruz
- Neurobiochemistry and Behavior Laboratory, National Institute of Neurology and Neurosurgery “Manuel Velasco Suárez”, Mexico City 14269, Mexico
| | - Sergio Enríquez-Flores
- Laboratorio de Biomoléculas y Salud Infantil, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico
| | - Carlos Martínez-Conde
- Facultad de Farmacia, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Chamilpa, Cuernavaca 62209, Mexico
| | - Luis Miguel Canseco-Ávila
- Facultad de Ciencias Químicas, Campus IV, Universidad Autónoma de Chiapas, Tapachula City 30700, Mexico
| | - Fernando Gómez-Chávez
- Laboratorio de Enfermedades Osteoarticulares e Inmunológicas, Sección de Estudios de Posgrado e Investigación, Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Mexico City 07320, Mexico
| | - Saúl Gómez-Manzo
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico
- Correspondence: ; Tel.: +52-55-1084-0900 (ext. 1442)
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Xia N, Guo X, Guo Q, Gupta N, Ji N, Shen B, Xiao L, Feng Y. Metabolic flexibilities and vulnerabilities in the pentose phosphate pathway of the zoonotic pathogen Toxoplasma gondii. PLoS Pathog 2022; 18:e1010864. [PMID: 36121870 PMCID: PMC9521846 DOI: 10.1371/journal.ppat.1010864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 09/29/2022] [Accepted: 09/08/2022] [Indexed: 11/18/2022] Open
Abstract
Metabolic pathways underpin the growth and virulence of intracellular parasites and are therefore promising antiparasitic targets. The pentose phosphate pathway (PPP) is vital in most organisms, providing a reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) and ribose sugar for nucleotide synthesis; however, it has not yet been studied in Toxoplasma gondii, a widespread intracellular pathogen and a model protozoan organism. Herein, we show that T. gondii has a functional PPP distributed in the cytoplasm and nucleus of its acutely-infectious tachyzoite stage. We produced eight parasite mutants disrupting seven enzymes of the PPP in T. gondii. Our data show that of the seven PPP proteins, the two glucose-6-phosphate dehydrogenases (TgG6PDH1, TgG6PDH2), one of the two 6-phosphogluconate dehydrogenases (Tg6PGDH1), ribulose-5-phosphate epimerase (TgRuPE) and transaldolase (TgTAL) are dispensable in vitro as well as in vivo, disclosing substantial metabolic plasticity in T. gondii. Among these, TgG6PDH2 plays a vital role in defense against oxidative stress by the pathogen. Further, we show that Tg6PGDH2 and ribulose-5-phosphate isomerase (TgRPI) are critical for tachyzoite growth. The depletion of TgRPI impairs the flux of glucose in central carbon pathways, and causes decreased expression of ribosomal, microneme and rhoptry proteins. In summary, our results demonstrate the physiological need of the PPP in T. gondii while unraveling metabolic flexibility and antiparasitic targets. Metabolic pathways are intimately associated with the survival and replication of parasitic Toxoplasma gondii and thus represent potential targets for antiparasitic strategies. Herein, we focused on the pentose phosphate pathway (PPP) in T. gondii and examined its roles in supporting the growth of this ubiquitous pathogen. We found that TgG6PDH1 and TgG6PDH2 were needed to defend oxidative stress but not for pentose synthesis. We revealed that inactivation of the Tg6PGDH2 and TgRPI severely impaired the asexual reproduction of tachyzoites. We also highlighted the remarkable metabolic plasticity in tachyzoites that enables them to acquire some of the PPP intermediates from multiple routes. This study provides significant insights into the carbon metabolism properties of Toxoplasma parasites, opening avenues for targeting this pathway to develop therapeutic interventions against toxoplasmosis.
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Affiliation(s)
- Ningbo Xia
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Xuefang Guo
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Qinghong Guo
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Nishith Gupta
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani (Hyderabad Campus), Hyderabad, India
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Nuo Ji
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Bang Shen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- * E-mail: (BS); (LX); (YF)
| | - Lihua Xiao
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- * E-mail: (BS); (LX); (YF)
| | - Yaoyu Feng
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- * E-mail: (BS); (LX); (YF)
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Dhumal TT, Kumar R, Paul A, Roy PK, Garg P, Singh S. Molecular explorations of the Leishmania donovani 6-phosphogluconolactonase enzyme, a key player in the pentose phosphate pathway. Biochimie 2022; 202:212-225. [PMID: 36037881 DOI: 10.1016/j.biochi.2022.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 07/12/2022] [Accepted: 08/09/2022] [Indexed: 11/18/2022]
Abstract
The enzymes of the pentose phosphate pathway are vital to survival in kinetoplastids. The second step of the pentose phosphate pathway involves hydrolytic cleavage of 6-phosphogluconolactone to 6-phosphogluconic acid by 6- phosphogluconolactonase (6PGL). In the present study, Leishmania donovani 6PGL (Ld6PGL) was cloned and overexpressed in bacterial expression system. Comparative sequence analysis revealed the conserved sequence motifs, functionally and structurally important residues in 6PGL family. In silico amino acid substitution study and interacting partners of 6PGL were predicted. The Ld6PGL enzyme was found to be active in the assay and in the parasites. Specificity was confirmed by western blot analysis. The ∼30 kDa protein was found to be a dimer in MALDI, glutaraldehyde crosslinking and size exclusion chromatography studies. Kinetic analysis and structural stability studies of Ld6PGL were performed with denaturants and at varied temperature. Computational 3D Structural modelling of Ld6PGL elucidates that it has a similar α/β hydrolase fold structural topology as in other members of 6PGL family. The three loops are found in extended form when the structure is compared with the human 6PGL (Hs6PGL). Further, enzyme substrate binding mode and its mechanism were investigated using the molecular docking and molecular simulation studies. Interesting dynamics action of substrate 6-phosphogluconolactone was observed into active site during MD simulation. Interesting differences were observed between host and parasite enzyme which pointed towards its potential to be explored as an antileishmanial drug target. This study forms the basis for further analysis of the role of Ld6PGL in combating oxidative stress in Leishmania.
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Affiliation(s)
- Tushar Tukaram Dhumal
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, 160062, Punjab, India
| | - Rajender Kumar
- Department of Clinical Microbiology, Umeå University, SE-90185, Umeå, Sweden
| | - Anindita Paul
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, 160062, Punjab, India
| | - Pradyot Kumar Roy
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, 160062, Punjab, India
| | - Prabha Garg
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, 160062, Punjab, India
| | - Sushma Singh
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, 160062, Punjab, India.
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Alencar N, Sola I, Linares M, Juárez-Jiménez J, Pont C, Viayna A, Vílchez D, Sampedro C, Abad P, Pérez-Benavente S, Lameira J, Bautista JM, Muñoz-Torrero D, Luque FJ. First homology model of Plasmodium falciparum glucose-6-phosphate dehydrogenase: Discovery of selective substrate analog-based inhibitors as novel antimalarial agents. Eur J Med Chem 2018; 146:108-122. [PMID: 29407943 DOI: 10.1016/j.ejmech.2018.01.044] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Revised: 12/27/2017] [Accepted: 01/15/2018] [Indexed: 01/07/2023]
Abstract
In Plasmodium falciparum the bifunctional enzyme glucose-6-phosphate dehydrogenase‒6-phosphogluconolactonase (PfG6PD‒6PGL) is involved in the catalysis of the first reaction of the pentose phosphate pathway. Since this enzyme has a key role in parasite development, its unique structure represents a potential target for the discovery of antimalarial drugs. Here we describe the first 3D structural model of the G6PD domain of PfG6PD‒6PGL. Compared to the human enzyme (hG6PD), the 3D model has enabled the identification of a key difference in the substrate-binding site, which involves the replacement of Arg365 in hG6PD by Asp750 in PfG6PD. In a prospective validation of the model, this critical change has been exploited to rationally design a novel family of substrate analog-based inhibitors that can display the necessary selectivity towards PfG6PD. A series of glucose derivatives featuring an α-methoxy group at the anomeric position and different side chains at position 6 bearing distinct basic functionalities has been synthesized, and their PfG6PD and hG6PD inhibitory activities and their toxicity against parasite and mammalian cells have been assessed. Several compounds displayed micromolar affinity (Ki up to 23 μM), favorable selectivity (up to > 26-fold), and low cytotoxicity. Phenotypic assays with P. falciparum cultures revealed high micromolar IC50 values, likely as a result of poor internalization of the compounds in the parasite cell. Overall, these results endorse confidence to the 3D model of PfG6PD, paving the way for the use of target-based drug design approaches in antimalarial drug discovery studies around this promising target.
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Affiliation(s)
- Nelson Alencar
- Department of Nutrition, Food Science and Gastronomy, Faculty of Pharmacy and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Av. Prat de la Riba 171, E-08921 Santa Coloma de Gramenet, Spain
| | - Irene Sola
- Laboratory of Pharmaceutical Chemistry (CSIC Associated Unit), Faculty of Pharmacy and Food Sciences and IBUB, University of Barcelona, Av. Joan XXIII 27-31, E-08028 Barcelona, Spain
| | - María Linares
- Research Institute Hospital 12 de Octubre, Avda. de Cordoba s/n, 28041 Madrid, Spain
| | - Jordi Juárez-Jiménez
- Department of Nutrition, Food Science and Gastronomy, Faculty of Pharmacy and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Av. Prat de la Riba 171, E-08921 Santa Coloma de Gramenet, Spain
| | - Caterina Pont
- Laboratory of Pharmaceutical Chemistry (CSIC Associated Unit), Faculty of Pharmacy and Food Sciences and IBUB, University of Barcelona, Av. Joan XXIII 27-31, E-08028 Barcelona, Spain
| | - Antonio Viayna
- Department of Nutrition, Food Science and Gastronomy, Faculty of Pharmacy and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Av. Prat de la Riba 171, E-08921 Santa Coloma de Gramenet, Spain
| | - David Vílchez
- Department of Nutrition, Food Science and Gastronomy, Faculty of Pharmacy and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Av. Prat de la Riba 171, E-08921 Santa Coloma de Gramenet, Spain
| | - Cristina Sampedro
- Laboratory of Pharmaceutical Chemistry (CSIC Associated Unit), Faculty of Pharmacy and Food Sciences and IBUB, University of Barcelona, Av. Joan XXIII 27-31, E-08028 Barcelona, Spain
| | - Paloma Abad
- Research Institute Hospital 12 de Octubre, Avda. de Cordoba s/n, 28041 Madrid, Spain; Department of Biochemistry and Molecular Biology, Universidad Complutense de Madrid, Facultad de Veterinaria, Ciudad Universitaria, 28040 Madrid, Spain
| | - Susana Pérez-Benavente
- Department of Biochemistry and Molecular Biology, Universidad Complutense de Madrid, Facultad de Veterinaria, Ciudad Universitaria, 28040 Madrid, Spain
| | - Jerónimo Lameira
- Laboratório de Planejamento e Desenvolvimento de Fármacos-LPDF, Instituto de Ciências Exatas e Naturais- ICEN, Universidade Federal do Pará - UFPA, Av. Augusto Correa, Nº 1- Bairro: Guamá, Cep: 66.075-900 Belém-Pará, Brazil
| | - José M Bautista
- Research Institute Hospital 12 de Octubre, Avda. de Cordoba s/n, 28041 Madrid, Spain; Department of Biochemistry and Molecular Biology, Universidad Complutense de Madrid, Facultad de Veterinaria, Ciudad Universitaria, 28040 Madrid, Spain
| | - Diego Muñoz-Torrero
- Laboratory of Pharmaceutical Chemistry (CSIC Associated Unit), Faculty of Pharmacy and Food Sciences and IBUB, University of Barcelona, Av. Joan XXIII 27-31, E-08028 Barcelona, Spain.
| | - F Javier Luque
- Department of Nutrition, Food Science and Gastronomy, Faculty of Pharmacy and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Av. Prat de la Riba 171, E-08921 Santa Coloma de Gramenet, Spain.
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Inhibition of Plasmodium falciparum proliferation in vitro by double-stranded RNA nanoparticle against malaria topoisomerase II. Exp Parasitol 2016; 164:84-90. [DOI: 10.1016/j.exppara.2016.03.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Revised: 03/02/2016] [Accepted: 03/04/2016] [Indexed: 11/21/2022]
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8
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Allen SM, Lim EE, Jortzik E, Preuss J, Chua HH, MacRae JI, Rahlfs S, Haeussler K, Downton MT, McConville MJ, Becker K, Ralph SA. Plasmodium falciparum glucose-6-phosphate dehydrogenase 6-phosphogluconolactonase is a potential drug target. FEBS J 2015. [PMID: 26198663 DOI: 10.1111/febs.13380] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The malarial parasite Plasmodium falciparum is exposed to substantial redox challenges during its complex life cycle. In intraerythrocytic parasites, haemoglobin breakdown is a major source of reactive oxygen species. Deficiencies in human glucose-6-phosphate dehydrogenase, the initial enzyme in the pentose phosphate pathway (PPP), lead to a disturbed redox equilibrium in infected erythrocytes and partial protection against severe malaria. In P. falciparum, the first two reactions of the PPP are catalysed by the bifunctional enzyme glucose-6-phosphate dehydrogenase 6-phosphogluconolactonase (PfGluPho). This enzyme differs structurally from its human counterparts and represents a potential target for drugs. In the present study we used epitope tagging of endogenous PfGluPho to verify that the enzyme localises to the parasite cytosol. Furthermore, attempted double crossover disruption of the PfGluPho gene indicates that the enzyme is essential for the growth of blood stage parasites. As a further step towards targeting PfGluPho pharmacologically, ellagic acid was characterised as a potent PfGluPho inhibitor with an IC50 of 76 nM. Interestingly, pro-oxidative drugs or treatment of the parasites with H2O2 only slightly altered PfGluPho expression or activity under the conditions tested. Furthermore, metabolic profiling suggested that pro-oxidative drugs do not significantly perturb the abundance of PPP intermediates. These data indicate that PfGluPho is essential in asexual parasites, but that the oxidative arm of the PPP is not strongly regulated in response to oxidative challenge.
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Affiliation(s)
- Stacey M Allen
- Department of Biochemistry and Molecular Biology, University of Melbourne, Australia
| | - Erin E Lim
- Department of Biochemistry and Molecular Biology, University of Melbourne, Australia
| | - Esther Jortzik
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, Germany
| | - Janina Preuss
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, Germany
| | - Hwa Huat Chua
- Department of Biochemistry and Molecular Biology, University of Melbourne, Australia
| | - James I MacRae
- Department of Biochemistry and Molecular Biology, University of Melbourne, Australia
| | - Stefan Rahlfs
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, Germany
| | - Kristina Haeussler
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, Germany
| | | | - Malcolm J McConville
- Department of Biochemistry and Molecular Biology, University of Melbourne, Australia
| | - Katja Becker
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, Germany
| | - Stuart A Ralph
- Department of Biochemistry and Molecular Biology, University of Melbourne, Australia
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9
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Gene fusion analysis in the battle against the African endemic sleeping sickness. PLoS One 2013; 8:e68854. [PMID: 23874788 PMCID: PMC3714255 DOI: 10.1371/journal.pone.0068854] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 06/05/2013] [Indexed: 01/15/2023] Open
Abstract
The protozoan Trypanosoma brucei causes African Trypanosomiasis or sleeping sickness in humans, which can be lethal if untreated. Most available pharmacological treatments for the disease have severe side-effects. The purpose of this analysis was to detect novel protein-protein interactions (PPIs), vital for the parasite, which could lead to the development of drugs against this disease to block the specific interactions. In this work, the Domain Fusion Analysis (Rosetta Stone method) was used to identify novel PPIs, by comparing T. brucei to 19 organisms covering all major lineages of the tree of life. Overall, 49 possible protein-protein interactions were detected, and classified based on (a) statistical significance (BLAST e-value, domain length etc.), (b) their involvement in crucial metabolic pathways, and (c) their evolutionary history, particularly focusing on whether a protein pair is split in T. brucei and fused in the human host. We also evaluated fusion events including hypothetical proteins, and suggest a possible molecular function or involvement in a certain biological process. This work has produced valuable results which could be further studied through structural biology or other experimental approaches so as to validate the protein-protein interactions proposed here. The evolutionary analysis of the proteins involved showed that, gene fusion or gene fission events can happen in all organisms, while some protein domains are more prone to fusion and fission events and present complex evolutionary patterns.
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10
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Preuss J, Maloney P, Peddibhotla S, Hedrick MP, Hershberger P, Gosalia P, Milewski M, Li YL, Sugarman E, Hood B, Suyama E, Nguyen K, Vasile S, Sergienko E, Mangravita-Novo A, Vicchiarelli M, McAnally D, Smith LH, Roth GP, Diwan J, Chung TDY, Jortzik E, Rahlfs S, Becker K, Pinkerton AB, Bode L. Discovery of a Plasmodium falciparum glucose-6-phosphate dehydrogenase 6-phosphogluconolactonase inhibitor (R,Z)-N-((1-ethylpyrrolidin-2-yl)methyl)-2-(2-fluorobenzylidene)-3-oxo-3,4-dihydro-2H-benzo[b][1,4]thiazine-6-carboxamide (ML276) that reduces parasite growth in vitro. J Med Chem 2012; 55:7262-72. [PMID: 22813531 DOI: 10.1021/jm300833h] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A high-throughput screen of the NIH's MLSMR collection of ∼340000 compounds was undertaken to identify compounds that inhibit Plasmodium falciparum glucose-6-phosphate dehydrogenase (PfG6PD). PfG6PD is important for proliferating and propagating P. falciparum and differs structurally and mechanistically from the human orthologue. The reaction catalyzed by glucose-6-phosphate dehydrogenase (G6PD) is the first, rate-limiting step in the pentose phosphate pathway (PPP), a key metabolic pathway sustaining anabolic needs in reductive equivalents and synthetic materials in fast-growing cells. In P. falciparum , the bifunctional enzyme glucose-6-phosphate dehydrogenase-6-phosphogluconolactonase (PfGluPho) catalyzes the first two steps of the PPP. Because P. falciparum and infected host red blood cells rely on accelerated glucose flux, they depend on the G6PD activity of PfGluPho. The lead compound identified from this effort, (R,Z)-N-((1-ethylpyrrolidin-2-yl)methyl)-2-(2-fluorobenzylidene)-3-oxo-3,4-dihydro-2H-benzo[b][1,4]thiazine-6-carboxamide, 11 (ML276), is a submicromolar inhibitor of PfG6PD (IC(50) = 889 nM). It is completely selective for the enzyme's human isoform, displays micromolar potency (IC(50) = 2.6 μM) against P. falciparum in culture, and has good drug-like properties, including high solubility and moderate microsomal stability. Studies testing the potential advantage of inhibiting PfG6PD in vivo are in progress.
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Affiliation(s)
- Janina Preuss
- Department of Pediatrics, University of California, San Diego, La Jolla, California 92037, United States
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11
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Preuss J, Jortzik E, Becker K. Glucose-6-phosphate metabolism in Plasmodium falciparum. IUBMB Life 2012; 64:603-11. [PMID: 22639416 DOI: 10.1002/iub.1047] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 04/07/2012] [Indexed: 01/13/2023]
Abstract
Malaria is still one of the most threatening diseases worldwide. The high drug resistance rates of malarial parasites make its eradication difficult and furthermore necessitate the development of new antimalarial drugs. Plasmodium falciparum is responsible for severe malaria and therefore of special interest with regard to drug development. Plasmodium parasites are highly dependent on glucose and very sensitive to oxidative stress; two observations that drew interest to the pentose phosphate pathway (PPP) with its key enzyme glucose-6-phosphate dehydrogenase (G6PD). A central position of the PPP for malaria parasites is supported by the fact that human G6PD deficiency protects to a certain degree from malaria infections. Plasmodium parasites and the human host possess a complete PPP, both of which seem to be important for the parasites. Interestingly, there are major differences between parasite and human G6PD, making the enzyme of Plasmodium a promising target for antimalarial drug design. This review gives an overview of the current state of research on glucose-6-phosphate metabolism in P. falciparum and its impact on malaria infections. Moreover, the unique characteristics of the enzyme G6PD in P. falciparum are discussed, upon which its current status as promising target for drug development is based.
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Affiliation(s)
- Janina Preuss
- Chair of Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University, Giessen, Germany
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12
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Preuss J, Hedrick M, Sergienko E, Pinkerton A, Mangravita-Novo A, Smith L, Marx C, Fischer E, Jortzik E, Rahlfs S, Becker K, Bode L. High-throughput screening for small-molecule inhibitors of plasmodium falciparum glucose-6-phosphate dehydrogenase 6-phosphogluconolactonase. ACTA ACUST UNITED AC 2012; 17:738-51. [PMID: 22496096 DOI: 10.1177/1087057112442382] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Plasmodium falciparum causes severe malaria infections in millions of people every year. The parasite is developing resistance to the most common antimalarial drugs, which creates an urgent need for new therapeutics. A promising and attractive target for antimalarial drug design is the bifunctional enzyme glucose-6-phosphate dehydrogenase-6-phosphogluconolactonase (PfGluPho) of P. falciparum, which catalyzes the key step in the parasites' pentose phosphate pathway. In this study, we describe the development of a high-throughput screening assay to identify small-molecule inhibitors of recombinant PfGluPho. The optimized assay was used to screen three small-molecule compound libraries-namely, LOPAC (Sigma-Aldrich, 1280 compounds), Spectrum (MicroSource Discovery Systems, 1969 compounds), and DIVERSet (ChemBridge, 49 971 compounds). These pilot screens identified 899 compounds that inhibited PfGluPho activity by at least 50%. Selected compounds were further studied to determine IC(50) values in an orthogonal assay, the type of inhibition and reversibility, and effects on P. falciparum growth. Screening results and follow-up studies for selected PfGluPho inhibitors are presented. Our high-throughput screening assay may provide the basis to identify novel and urgently needed antimalarial drugs.
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Affiliation(s)
- Janina Preuss
- Department of Pediatrics, University of California, San Diego, CA, USA
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Glucose-6-phosphate dehydrogenase-6-phosphogluconolactonase: a unique bifunctional enzyme from Plasmodium falciparum. Biochem J 2011; 436:641-50. [PMID: 21443518 DOI: 10.1042/bj20110170] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The survival of malaria parasites in human RBCs (red blood cells) depends on the pentose phosphate pathway, both in Plasmodium falciparum and its human host. G6PD (glucose-6-phosphate dehydrogenase) deficiency, the most common human enzyme deficiency, leads to a lack of NADPH in erythrocytes, and protects from malaria. In P. falciparum, G6PD is combined with the second enzyme of the pentose phosphate pathway to create a unique bifunctional enzyme named GluPho (glucose-6-phosphate dehydrogenase-6-phosphogluconolactonase). In the present paper, we report for the first time the cloning, heterologous overexpression, purification and kinetic characterization of both enzymatic activities of full-length PfGluPho (P. falciparum GluPho), and demonstrate striking structural and functional differences with the human enzymes. Detailed kinetic analyses indicate that PfGluPho functions on the basis of a rapid equilibrium random Bi Bi mechanism, where the binding of the second substrate depends on the first substrate. We furthermore show that PfGluPho is inhibited by S-glutathionylation. The availability of recombinant PfGluPho and the major differences to hG6PD (human G6PD) facilitate studies on PfGluPho as an excellent drug target candidate in the search for new antimalarial drugs.
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14
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Tuteja R, Pradhan A. PfeIF4E and PfeIF4A colocalize and their double-stranded RNA inhibits Plasmodium falciparum proliferation. Commun Integr Biol 2010; 3:611-3. [PMID: 21331256 DOI: 10.4161/cib.3.6.13396] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Accepted: 08/23/2010] [Indexed: 11/19/2022] Open
Abstract
Using bioinformatics and biochemical methods in the recent past we have reported the isolation and characterization of the main components of translation initiation complex eIF4F from malaria parasite Plasmodium falciparum. We reported that eukaryotic initiation factor 4A (eIF4A), eukaryotic initiation factor 4E (eIF4E), eukaryotic initiation factor 4G (eIF4G) and poly (A) binding protein (PABP) are structurally and functionally conserved in this parasite. In the present study we report further characterization of PfeIF4A and PfeIF4E. We report that PfeIF4A and PfeIF4E are co-localized and predominantly localized in the cytoplasm. The parasite cultures treated with co-addition of PfeIF4A and PfeIF4E double stranded RNA showed ∼67% growth inhibition suggesting that inhibition of two components of the same pathway is more effective for inhibiting the proliferation of the malaria parasite Plasmodium falciparum. These observations suggest that PfeIF4A and PfeIF4E are critical for parasite growth and survival.
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Affiliation(s)
- Renu Tuteja
- Malaria Group; International Centre for Genetic Engineering and Biotechnology; Aruna Asaf Ali Marg; New Delhi, India
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15
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Matrajt M. Non-coding RNA in apicomplexan parasites. Mol Biochem Parasitol 2010; 174:1-7. [PMID: 20566348 DOI: 10.1016/j.molbiopara.2010.06.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2009] [Revised: 05/29/2010] [Accepted: 06/01/2010] [Indexed: 11/28/2022]
Abstract
In recent years it has became evident that the transcriptome of most species has little protein-coding capacity and that the abundance of non-coding RNA was previously overlooked. Non-coding RNAs were initially thought to be transcriptional noise, however, a growing number of studies is showing that many of these RNAs have important regulatory functions. Here, we review the progress done in apicomplexan parasites in this rapidly growing field.
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Affiliation(s)
- Mariana Matrajt
- Department of Microbiology and Molecular Genetics, University of Vermont, Stafford Hall, Room 306, 95 Carrigan Drive, Burlington, VT 05405, United States.
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16
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Early transcriptional response to chloroquine of the Plasmodium falciparum antioxidant defence in sensitive and resistant clones. Acta Trop 2010; 114:109-15. [PMID: 20138820 DOI: 10.1016/j.actatropica.2010.01.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Revised: 01/14/2010] [Accepted: 01/28/2010] [Indexed: 12/27/2022]
Abstract
Resistance to chloroquine (CQ) in Plasmodium falciparum has a major impact on malaria control worldwide. To gain insight into early parasite stress response, mRNA expression profiles were determined for a set of 10 antioxidant defence genes in synchronized CQ-sensitive (3D7) and CQ-resistant (Dd2) clones under transient IC50 CQ-exposure (Dd2, 200 nM; 3D7, 14 nM). Upon 2-h CQ challenge, the mRNA upregulation detected was greater in 3D7 (six genes overexpressed at 1/3 of the intraerythrocytic cycle) than in Dd2 clone (three genes responding), providing evidence of an early transcriptional response to CQ-induced oxidative stress which might underlie some of the parasite's metabolic adaptation to the drug.
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17
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Phenotypic and transcriptomic analyses of Plasmodium falciparum protein kinase A catalytic subunit inhibition. Parasitol Res 2009; 105:1691-9. [DOI: 10.1007/s00436-009-1615-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Accepted: 08/24/2009] [Indexed: 10/20/2022]
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Sriwilaijaroen N, Boonma S, Attasart P, Pothikasikorn J, Panyim S, Noonpakdee W. Inhibition of Plasmodium falciparum proliferation in vitro by double-stranded RNA directed against malaria histone deacetylase. Biochem Biophys Res Commun 2009; 381:144-7. [PMID: 19338767 DOI: 10.1016/j.bbrc.2009.01.165] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2009] [Accepted: 01/23/2009] [Indexed: 10/21/2022]
Abstract
Acetylation and deacetylation of histones play important roles in transcription regulation, cell cycle progression and development events. The steady state status of histone acetylation is controlled by a dynamic equilibrium between competing histone acetylase and deacetylase (HDAC). We have used long PfHDAC-1 double-stranded (ds)RNA to interfere with its cognate mRNA expression and determined the effect on malaria parasite growth and development. Chloroquine- and pyrimethamine-resistant Plasmodium falciparum K1 strain was exposed to 1-25 microg of dsRNA/ml of culture for 48 h and growth was determined by [3H]-hypoxanthine incorporation and microscopic examination. Parasite culture treated with 10 microg/ml pfHDAC-1 dsRNA exhibited 47% growth inhibition when compared with either untreated control or culture treated with an unrelated dsRNA. PfHDAC-1 dsRNA specifically blocked maturation of trophozoite to schizont stages and decreased PfHDAC-1 transcript 44% in treated trophozoites. These results indicate the potential of HDAC-1 as a target for development of novel antimalarials.
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Affiliation(s)
- N Sriwilaijaroen
- Faculty of Medicine, Thammasat University (Rangsit Campus), Pathumthani 12120, Thailand
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19
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Kang S, Hong YS. RNA interference in infectious tropical diseases. THE KOREAN JOURNAL OF PARASITOLOGY 2008; 46:1-15. [PMID: 18344671 DOI: 10.3347/kjp.2008.46.1.1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Introduction of double-stranded RNA (dsRNA) into some cells or organisms results in degradation of its homologous mRNA, a process called RNA interference (RNAi). The dsRNAs are processed into short interfering RNAs (siRNAs) that subsequently bind to the RNA-induced silencing complex (RISC), causing degradation of target mRNAs. Because of this sequence-specific ability to silence target genes, RNAi has been extensively used to study gene functions and has the potential to control disease pathogens or vectors. With this promise of RNAi to control pathogens and vectors, this paper reviews the current status of RNAi in protozoans, animal parasitic helminths and disease-transmitting vectors, such as insects. Many pathogens and vectors cause severe parasitic diseases in tropical regions and it is difficult to control once the host has been invaded. Intracellularly, RNAi can be highly effective in impeding parasitic development and proliferation within the host. To fully realize its potential as a means to control tropical diseases, appropriate delivery methods for RNAi should be developed, and possible off-target effects should be minimized for specific gene suppression. RNAi can also be utilized to reduce vector competence to interfere with disease transmission, as genes critical for pathogenesis of tropical diseases are knockdowned via RNAi.
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Affiliation(s)
- Seokyoung Kang
- Department of Tropical Medicine, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA 70112, USA.
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20
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Radfar A, Diez A, Bautista JM. Chloroquine mediates specific proteome oxidative damage across the erythrocytic cycle of resistant Plasmodium falciparum. Free Radic Biol Med 2008; 44:2034-42. [PMID: 18397762 DOI: 10.1016/j.freeradbiomed.2008.03.010] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2008] [Revised: 03/04/2008] [Accepted: 03/11/2008] [Indexed: 12/22/2022]
Abstract
Resistance of Plasmodium falciparum to chloroquine hinders malaria control in endemic areas. Current hypotheses on the action mechanism of chloroquine evoke its ultimate interference with the parasite's oxidative defence systems. Through carbonyl derivatization by 2,4-dinitrophenylhydrazine and proteomics, we compared oxidatively modified proteins across the parasite's intraerythrocytic stages in untreated and transiently IC(50) chloroquine-treated cultures of the chloroquine-resistant P. falciparum strain Dd2. Functional plasmodial protein groups found to be most oxidatively damaged were among those central to the parasite's physiological processes, including protein folding, proteolysis, energy metabolism, signal transduction, and pathogenesis. While an almost constant number of oxidized proteins was detected across the P. falciparum life cycle, chloroquine treatment led to increases in both the extent of protein oxidation and the number of proteins oxidized as the intraerythrocytic cycle progressed to mature stages. Our data provide new insights into early molecular effects produced by chloroquine in the parasite, as well as into the normal protein-oxidation modifications along the parasite cycle. Oxidized proteins involved in the particular parasite drug-response suggest that chloroquine causes specific oxidative stress, sharing common features with eukaryotic cells. Targeting these processes might provide ways of combating chloroquine-resistance and developing new antimalarial drugs.
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Affiliation(s)
- Azar Radfar
- Department of Biochemistry and Molecular Biology IV, Universidad Complutense de Madrid, Facultad de Veterinaria, Ciudad Universitaria, 28040, Madrid, Spain
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Xue X, Zhang Q, Huang Y, Feng L, Pan W. No miRNA were found in Plasmodium and the ones identified in erythrocytes could not be correlated with infection. Malar J 2008; 7:47. [PMID: 18328111 PMCID: PMC2329658 DOI: 10.1186/1475-2875-7-47] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2007] [Accepted: 03/10/2008] [Indexed: 12/14/2022] Open
Abstract
Background The transcriptional regulation of Plasmodium during its complex life cycle requires sequential activation and/or repression of different genetic programmes. MicroRNAs (miRNAs) are a highly conserved class of non-coding RNAs that are important in regulating diverse cellular functions by sequence-specific inhibition of gene expression. What is know about double-stranded RNA-mediated gene silencing (RNAi) and posttranscriptional gene silencing (PTGS) in Plasmodium parasites entice us to speculate whether miRNAs can also function in Plasmodium-infected RBCs. Results Of 132 small RNA sequences, no Plasmodium-specific miRNAs have been found. However, a human miRNA, miR-451, was highly expressed, comprising approximately one third of the total identified miRNAs. Further analysis of miR-451 expression and malaria infection showed no association between the accumulation of miR-451 in Plasmodium falciparum-iRBCs, the life cycle stage of P. falciparum in the erythrocyte, or of P. berghei in mice. Moreover, treatment with an antisense oligonucleotide to miR-451 had no significant effect on the growth of the erythrocytic-stage P. falciparum. Methods Short RNAs from a mixed-stage of P. falciparum-iRBC were separated in a denaturing polyacrylamide gel and cloned into T vectors to create a cDNA library. Individual clones were then sequenced and further analysed by bioinformatics prediction to discover probable miRNAs in P. falciparum-iRBC. The association between miR-451 expression and the parasite were analysed by Northern blotting and antisense oligonucleotide (ASO) of miR-451. Conclusion These results contribute to eliminate the probability of miRNAs in P. falciparum. The absence of miRNA in P. falciparum could be correlated with absence of argonaute/dicer genes. In addition, the miR-451 accumulation in Plasmodium-infected RBCs is independent of parasite infection. Its accumulation might be only the residual of erythroid differentiation or a component to maintain the normal function of mature RBCs.
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Affiliation(s)
- Xiangyang Xue
- Institute for Infectious Diseases and Vaccine Development, Tongji University College of Medicine, 1239 Siping Road, Shanghai 200092, China.
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22
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Siau A, Toure FS, Ouwe-Missi-Oukem-Boyer O, Ciceron L, Mahmoudi N, Vaquero C, Froissard P, Bisvigou U, Bisser S, Coppee JY, Bischoff E, David PH, Mazier D. Whole-transcriptome analysis of Plasmodium falciparum field isolates: identification of new pathogenicity factors. J Infect Dis 2007; 196:1603-12. [PMID: 18008243 DOI: 10.1086/522012] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Accepted: 05/30/2007] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Severe malaria and one of its most important pathogenic processes, cerebral malaria, involves the sequestration of parasitized red blood cells (pRBCs) in brain postcapillary venules. Although the pathogenic mechanisms underlying malaria remain poorly characterized, it has been established that adhesion of pRBCs to endothelial cells (ECs) can result in cell apoptosis, which in turn may lead to disruption of the blood-brain barrier. The nature of the parasite molecules involved in the pathogenesis of severe malaria remains elusive. METHODS Whole-transcriptome profiling of nonapoptogenic versus apoptogenic parasite field isolates obtained from Gabonese children was performed with pan-genomic Plasmodium falciparum DNA microarrays; radiolabeled instead of fluorescent cDNAs were used to improve the sensitivity of signal detection. RESULTS Our methods allowed the identification of 59 genes putatively associated with the induction of EC apoptosis. Silencing of Plasmodium gene expression with specific double-stranded RNA was performed on 8 selected genes; 5 of these, named "Plasmodium apoptosis-linked pathogenicity factors" (PALPFs), were found to be linked to parasite apoptogenicity. Of these genes, 2 might act via parasite cytoadherence. CONCLUSION This is the first attempt to identify genes involved in parasite pathogenic mechanisms against human ECs. The finding of PALPFs illuminates perspectives for novel therapeutic strategies against cerebral complications of malaria.
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Affiliation(s)
- Anthony Siau
- Institut National de la Sante et de la Recherche Medicale U511, Paris 75013, France
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Rathjen T, Nicol C, McConkey G, Dalmay T. Analysis of short RNAs in the malaria parasite and its red blood cell host. FEBS Lett 2006; 580:5185-8. [PMID: 16963026 DOI: 10.1016/j.febslet.2006.08.063] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Revised: 07/14/2006] [Accepted: 08/11/2006] [Indexed: 02/01/2023]
Abstract
RNA interference (RNAi) is an RNA degradation process that involves short, double-stranded RNAs (dsRNA) as sequence specificity factors. The natural function of the RNAi machinery is to generate endogenous short double-stranded RNAs to regulate gene expression. It has been shown that treatment of Plasmodium falciparum, the etiologic agent of malaria, with dsRNA induces degradation of the corresponding microRNA (miRNA), yet typical RNAi-associated genes have not been identifiable in the parasite genome. To clarify this discrepancy we set out to clone short RNAs from P. falciparum-infected red blood cells and from purified parasites. We did not find any short RNA that was not a rRNA or tRNA fragment. Indeed, only known human miRNAs were isolated in parasite preparations indicating that very few if any short RNAs exist in P. falciparum. This suggests a different mechanism than classical RNAi in observations of dsRNA-mediated degradation. Of the human miRNAs identified, the human miRNA mir-451 accumulates at a very high level in both infected and healthy red blood cells. Interestingly, mir-451 was not detectable in a series of immortalised cell lines representing progenitor stages of all major blood lineages, suggesting that mir-451 may play a role in the differentiation of erythroid cells.
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MESH Headings
- Animals
- Cell Differentiation/drug effects
- Cell Differentiation/genetics
- Cloning, Molecular
- Erythrocytes/metabolism
- Erythrocytes/parasitology
- Gene Expression Regulation/drug effects
- Gene Expression Regulation/genetics
- Genome, Protozoan/drug effects
- Genome, Protozoan/genetics
- Humans
- Malaria/genetics
- Malaria/metabolism
- MicroRNAs/genetics
- MicroRNAs/metabolism
- Plasmodium falciparum/genetics
- Plasmodium falciparum/metabolism
- RNA Stability/drug effects
- RNA Stability/genetics
- RNA, Double-Stranded/genetics
- RNA, Double-Stranded/metabolism
- RNA, Double-Stranded/pharmacology
- RNA, Protozoan/genetics
- RNA, Protozoan/metabolism
- RNA, Ribosomal/genetics
- RNA, Ribosomal/metabolism
- RNA, Small Interfering
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
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Affiliation(s)
- Tina Rathjen
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
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