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Khan MM, Zaidi SS, Siyal FJ, Khan SU, Ishrat G, Batool S, Mustapha O, Khan S, Din FU. Statistical optimization of co-loaded rifampicin and pentamidine polymeric nanoparticles for the treatment of cutaneous leishmaniasis. J Drug Deliv Sci Technol 2022. [DOI: 10.1016/j.jddst.2022.104005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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2
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Ali V, Behera S, Nawaz A, Equbal A, Pandey K. Unique thiol metabolism in trypanosomatids: Redox homeostasis and drug resistance. ADVANCES IN PARASITOLOGY 2022; 117:75-155. [PMID: 35878950 DOI: 10.1016/bs.apar.2022.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Trypanosomatids are mainly responsible for heterogeneous parasitic diseases: Leishmaniasis, Sleeping sickness, and Chagas disease and control of these diseases implicates serious challenges due to the emergence of drug resistance. Redox-active biomolecules are the endogenous substances in organisms, which play important role in the regulation of redox homeostasis. The redox-active substances like glutathione, trypanothione, cysteine, cysteine persulfides, etc., and other inorganic intermediates (hydrogen peroxide, nitric oxide) are very useful as defence mechanism. In the present review, the suitability of trypanothione and other essential thiol molecules of trypanosomatids as drug targets are described in Leishmania and Trypanosoma. We have explored the role of tryparedoxin, tryparedoxin peroxidase, ascorbate peroxidase, superoxide dismutase, and glutaredoxins in the anti-oxidant mechanism and drug resistance. Up-regulation of some proteins in trypanothione metabolism helps the parasites in survival against drug pressure (sodium stibogluconate, Amphotericin B, etc.) and oxidative stress. These molecules accept electrons from the reduced trypanothione and donate their electrons to other proteins, and these proteins reduce toxic molecules, neutralize reactive oxygen, or nitrogen species; and help parasites to cope with oxidative stress. Thus, a better understanding of the role of these molecules in drug resistance and redox homeostasis will help to target metabolic pathway proteins to combat Leishmaniasis and trypanosomiases.
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Affiliation(s)
- Vahab Ali
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, ICMR-Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar, India.
| | - Sachidananda Behera
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, ICMR-Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar, India
| | - Afreen Nawaz
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, ICMR-Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar, India
| | - Asif Equbal
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, ICMR-Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar, India; Department of Botany, Araria College, Purnea University, Purnia, Bihar, India
| | - Krishna Pandey
- Department of Clinical Medicine, ICMR-Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar, India
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Bar Routaray C, Bhor R, Bai S, Kadam NS, Jagtap S, Doshi PJ, Sundar S, Sawant S, Kulkarni MJ, Pai K. SWATH-MS based quantitative proteomics analysis to evaluate the antileishmanial effect of Commiphora wightii- Guggul and Amphotericin B on a clinical isolate of Leishmania donovani. J Proteomics 2020; 223:103800. [DOI: 10.1016/j.jprot.2020.103800] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 04/25/2020] [Accepted: 04/27/2020] [Indexed: 12/15/2022]
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Paape D, Prendergast CT, Price HP, Doehl JSP, Smith DF. Genetic validation of Leishmania genes essential for amastigote survival in vivo using N-myristoyltransferase as a model. Parasit Vectors 2020; 13:132. [PMID: 32171322 PMCID: PMC7071782 DOI: 10.1186/s13071-020-3999-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 02/26/2020] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Proving that specific genes are essential for the intracellular viability of Leishmania parasites within macrophages remains a challenge for the identification of suitable targets for drug development. This is especially evident in the absence of a robust inducible expression system or functioning RNAi machinery that works in all Leishmania species. Currently, if a target gene of interest in extracellular parasites can only be deleted from its genomic locus in the presence of ectopic expression from a wild type copy, it is assumed that this gene will also be essential for viability in disease-promoting intracellular parasites. However, functional essentiality must be proven independently in both life-cycle stages for robust validation of the gene of interest as a putative target for chemical intervention. METHODS Here, we have used plasmid shuffle methods in vivo to provide supportive genetic evidence that N-myristoyltransferase (NMT) is essential for Leishmania viability throughout the parasite life-cycle. Following confirmation of NMT essentiality in vector-transmitted promastigotes, a range of mutant parasites were used to infect mice prior to negative selection pressure to test the hypothesis that NMT is also essential for parasite viability in an established infection. RESULTS Ectopically-expressed NMT was only dispensable under negative selection in the presence of another copy. Total parasite burdens in animals subjected to negative selection were comparable to control groups only if an additional NMT copy, not affected by the negative selection, was expressed. CONCLUSIONS NMT is an essential gene in all parasite life-cycle stages, confirming its role as a genetically-validated target for drug development.
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Affiliation(s)
- Daniel Paape
- Centre for Immunology and Infection, Department of Biology, University of York, York, YO10 5DD UK
- Present Address: Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8TA UK
| | - Catriona T. Prendergast
- Centre for Immunology and Infection, Department of Biology, University of York, York, YO10 5DD UK
- Present Address: Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8TA UK
| | - Helen P. Price
- Centre for Immunology and Infection, Department of Biology, University of York, York, YO10 5DD UK
- Present Address: Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Newcastle-under-Lyme, ST5 5BG UK
| | - Johannes S. P. Doehl
- Centre for Immunology and Infection, Department of Biology, University of York, York, YO10 5DD UK
| | - Deborah F. Smith
- Centre for Immunology and Infection, Department of Biology, University of York, York, YO10 5DD UK
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Abstract
AbstractDuring three decades, only about 20 new drugs have been developed for malaria, tuberculosis and all neglected tropical diseases (NTDs). This critical situation was reached because NTDs represent only 10% of health research investments; however, they comprise about 90% of the global disease burden. Computational simulations applied in virtual screening (VS) strategies are very efficient tools to identify pharmacologically active compounds or new indications for drugs already administered for other diseases. One of the advantages of this approach is the low time-consuming and low-budget first stage, which filters for testing experimentally a group of candidate compounds with high chances of binding to the target and present trypanocidal activity. In this work, we review the most common VS strategies that have been used for the identification of new drugs with special emphasis on those applied to trypanosomiasis and leishmaniasis. Computational simulations based on the selected protein targets or their ligands are explained, including the method selection criteria, examples of successful VS campaigns applied to NTDs, a list of validated molecular targets for drug development and repositioned drugs for trypanosomatid-caused diseases. Thereby, here we present the state-of-the-art of VS and drug repurposing to conclude pointing out the future perspectives in the field.
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Eissa MM, Amer EI, Mossallam SF, Gomaa MM, Baddour NM. Miltefosine for Old World cutaneous leishmaniasis: An experimental study on Leishmania major infected mice. ALEXANDRIA JOURNAL OF MEDICINE 2019. [DOI: 10.1016/j.ajme.2012.04.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Affiliation(s)
- Maha M. Eissa
- Department of Medical Parasitology, Faculty of Medicine , Alexandria University, Alexandria, Egypt
| | - Eglal I. Amer
- Department of Medical Parasitology, Faculty of Medicine , Alexandria University, Alexandria, Egypt
| | - Shereen F. Mossallam
- Department of Medical Parasitology, Faculty of Medicine , Alexandria University, Alexandria, Egypt
| | - Maha M. Gomaa
- Department of Medical Parasitology, Faculty of Medicine , Alexandria University, Alexandria, Egypt
| | - Nahed M. Baddour
- Department of Pathology, Faculty of Medicine , Alexandria University, Alexandria, Egypt
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Dar MJ, Din FU, Khan GM. Sodium stibogluconate loaded nano-deformable liposomes for topical treatment of leishmaniasis: macrophage as a target cell. Drug Deliv 2018; 25:1595-1606. [PMID: 30105918 PMCID: PMC6095017 DOI: 10.1080/10717544.2018.1494222] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Topical drug delivery against cutaneous leishmaniasis (CL) signifies an effective alternate for improving the availability and reducing the toxicity associated with the parenteral administration of conventional sodium stibogluconate (SSG) injection. The basic aim of the study was to develop nano-deformable liposomes (NDLs) for the dermal delivery of SSG against CL. NDLs were formulated by a modified thin film hydration method and optimized via Box–Behnken statistical design. The physicochemical properties of SSG-NDLs were established in terms of vesicle size (195.1 nm), polydispersity index (0.158), zeta potential (−32.8 mV), and entrapment efficiency (35.26%). Moreover, deformability index, in vitro release, and macrophage uptake studies were also accomplished. SSG-NDLs were entrapped within Carbopol gel network for the ease of skin application. The ex vivo skin permeation study revealed that SSG-NDLs gel provided 10-fold higher skin retention towards the deeper skin layers, attained without use of classical permeation enhancers. Moreover, in vivo skin irritation and histopathological studies verified safety of the topically applied formulation. Interestingly, the cytotoxic potential of SSG-NDLs (1.3 mg/ml) was higher than plain SSG (1.65 mg/ml). The anti-leishmanial activity on intramacrophage amastigote model of Leishmania tropica showed that IC50 value of the SSG-NDLs was ∼ fourfold lower than the plain drug solution with marked increase in the selectivity index. The in vivo results displayed higher anti-leishmanial activity by efficiently healing lesion and successfully reducing parasite burden. Concisely, the outcomes indicated that the targeted delivery of SSG could be accomplished by using topically applied NDLs for the effective treatment of CL.
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Affiliation(s)
- M Junaid Dar
- a Department of Pharmacy, Faculty of Biological Sciences , Quaid-i-Azam University , Islamabad , Pakistan
| | - Fakhar Ud Din
- a Department of Pharmacy, Faculty of Biological Sciences , Quaid-i-Azam University , Islamabad , Pakistan
| | - Gul Majid Khan
- a Department of Pharmacy, Faculty of Biological Sciences , Quaid-i-Azam University , Islamabad , Pakistan
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8
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Targeting the Pentose Phosphate Pathway: Characterization of a New 6PGL Inhibitor. Biophys J 2018; 115:2114-2126. [PMID: 30467026 DOI: 10.1016/j.bpj.2018.10.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 10/12/2018] [Accepted: 10/17/2018] [Indexed: 12/19/2022] Open
Abstract
Human African trypanosomiasis, or sleeping sickness, is a lethal disease caused by the protozoan parasite Trypanosoma brucei. However, although many efforts have been made to understand the biochemistry of this parasite, drug development has led to treatments that are of limited efficiency and of great toxicity. To develop new drugs, new targets must be identified, and among the several metabolic processes of trypanosomes that have been proposed as drug targets, carbohydrate metabolism (glycolysis and the pentose phosphate pathway (PPP)) appears as a promising one. As far as the PPP is concerned, a limited number of studies are related to the glucose-6-phosphate dehydrogenase. In this work, we have focused on the activity of the second PPP enzyme (6-phospho-gluconolactonase (6PGL)) that transforms 6-phosphogluconolactone into 6-phosphogluconic acid. A lactam analog of the natural substrate has been synthesized, and binding of the ligand to 6PGL has been investigated by NMR titration. The ability of this ligand to inhibit 6PGL has also been demonstrated using ultraviolet experiments, and protein-inhibitor interactions have been investigated through docking calculations and molecular dynamics simulations. In addition, a marginal inhibition of the third enzyme of the PPP (6-phosphogluconate dehydrogenase) was also demonstrated. Our results thus open new prospects for targeting T. brucei.
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9
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Sakthivel S, Habeeb SKM, Raman C. Screening of broad spectrum natural pesticides against conserved target arginine kinase in cotton pests by molecular modeling. J Biomol Struct Dyn 2018; 37:1022-1042. [DOI: 10.1080/07391102.2018.1447514] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Seethalakshmi Sakthivel
- Entomoinformatics Lab, School of Bioengineering, SRM University, Kattankulathur, Tamilnadu 603203, India
- Department of Genetic Engineering, School of Bioengineering, SRM University, Kattankulathur, Tamilnadu 603203, India
| | - S. K. M. Habeeb
- Entomoinformatics Lab, School of Bioengineering, SRM University, Kattankulathur, Tamilnadu 603203, India
- Department of Genetic Engineering, School of Bioengineering, SRM University, Kattankulathur, Tamilnadu 603203, India
| | - Chandrasekar Raman
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA
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Álvarez Touron GI. Bioguided Design of Trypanosomicidal Compounds: A Successful Strategy in Drug Discovery. Methods Mol Biol 2018; 1824:139-163. [PMID: 30039405 DOI: 10.1007/978-1-4939-8630-9_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Drug development is a long and expensive process that takes about 15 years and is mostly carried out by the pharmaceutical industry. In the case of the diseases produced by trypanosomatids, this development is poorly performed by the pharmaceutical industry. As a result the academia is the one that take a leading role with the drug development process. More effective and economic methodologies to obtain safe compounds and with strong trypanosomicidal activity are urgently needed. In this work, a series of methods are described to obtain bioactive molecules with antiparasitic activity and good pharmacological profiles.
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Duncan SM, Jones NG, Mottram JC. Recent advances in Leishmania reverse genetics: Manipulating a manipulative parasite. Mol Biochem Parasitol 2017. [DOI: 10.1016/j.molbiopara.2017.06.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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12
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Hazra S, Ghosh S, Hazra B. Phytochemicals With Antileishmanial Activity. STUDIES IN NATURAL PRODUCTS CHEMISTRY 2017. [DOI: 10.1016/b978-0-444-63931-8.00008-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Increased Abundance of Proteins Involved in Resistance to Oxidative and Nitrosative Stress at the Last Stages of Growth and Development of Leishmania amazonensis Promastigotes Revealed by Proteome Analysis. PLoS One 2016; 11:e0164344. [PMID: 27776144 PMCID: PMC5077082 DOI: 10.1371/journal.pone.0164344] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 09/23/2016] [Indexed: 12/23/2022] Open
Abstract
Leishmania amazonensis is one of the major etiological agents of the neglected, stigmatizing disease termed american cutaneous leishmaniasis (ACL). ACL is a zoonosis and rodents are the main reservoirs. Most cases of ACL are reported in Brazil, Bolivia, Colombia and Peru. The biological cycle of the parasite is digenetic because sand fly vectors transmit the motile promastigote stage to the mammalian host dermis during blood meal intakes. The amastigote stage survives within phagocytes of the mammalian host. The purpose of this study is detection and identification of changes in protein abundance by 2DE/MALDI-TOF/TOF at the main growth phases of L. amazonensis promastigotes in axenic culture and the differentiation process that takes place simultaneously. The average number of proteins detected per gel is 202 and the non-redundant cumulative number is 339. Of those, 63 are differentially abundant throughout growth and simultaneous differentiation of L. amazonensis promastigotes. The main finding is that certain proteins involved in resistance to nitrosative and oxidative stress are more abundant at the last stages of growth and differentiation of cultured L. amazonensis promastigotes. These proteins are the arginase, a light variant of the tryparedoxin peroxidase, the iron superoxide dismutase, the regulatory subunit of the protein kinase A and a light HSP70 variant. These data taken together with the decrease of the stress-inducible protein 1 levels are additional evidence supporting the previously described pre-adaptative hypothesis, which consists of preparation in advance towards the amastigote stage.
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Singh K, Singh KP, Equbal A, Suman SS, Zaidi A, Garg G, Pandey K, Das P, Ali V. Interaction between cysteine synthase and serine O-acetyltransferase proteins and their stage specific expression in Leishmania donovani. Biochimie 2016; 131:29-44. [PMID: 27638321 DOI: 10.1016/j.biochi.2016.09.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 09/05/2016] [Accepted: 09/05/2016] [Indexed: 01/14/2023]
Abstract
Leishmania possess a unique trypanothione redox metabolism with undebated roles in protection from oxidative damage and drug resistance. The biosynthesis of trypanothione depends on l-cysteine bioavailability which is regulated by cysteine biosynthesis pathway. The de novo cysteine biosynthesis pathway is comprised of serine O-acetyltransferase (SAT) and cysteine synthase (CS) enzymes which sequentially mediate two consecutive steps of cysteine biosynthesis, and is absent in mammalian host. However, despite the apparent dependency of redox metabolism on cysteine biosynthesis pathway, the role of SAT and CS in redox homeostasis has been unexplored in Leishmania parasites. Herein, we have characterized CS and SAT to investigate their interaction and relative abundance of these proteins in promastigote vs. amastigote growth stages of L. donovani. CS and SAT genes of L. donovani (LdCS and LdSAT) were cloned, expressed, and fusion proteins purified to homogeneity with affinity column chromatography. Purified LdCS contains PLP as cofactor and showed optimum enzymatic activity at pH 7.5. Enzyme kinetics showed that LdCS catalyses the synthesis of cysteine using O-acetylserine and sulfide with a Km of 15.86 mM and 0.17 mM, respectively. Digitonin fractionation and indirect immunofluorescence microscopy showed that LdCS and LdSAT are localized in the cytoplasm of promastigotes. Size exclusion chromatography, co-purification, pull down and immuno-precipitation assays demonstrated a stable complex formation between LdCS and LdSAT proteins. Furthermore, LdCS and LdSAT proteins expression/activity was upregulated in amastigote growth stage of the parasite. Thus, the stage specific differential expression of LdCS and LdSAT suggests that it may have a role in the redox homeostasis of Leishmania.
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Affiliation(s)
- Kuljit Singh
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna, 800007, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, EPIP Complex, Hajipur, 844102, India
| | - Krishn Pratap Singh
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna, 800007, India
| | - Asif Equbal
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna, 800007, India
| | - Shashi S Suman
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna, 800007, India
| | - Amir Zaidi
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna, 800007, India
| | - Gaurav Garg
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna, 800007, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, EPIP Complex, Hajipur, 844102, India
| | - Krishna Pandey
- Department of Clinical Medicine, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna, 800007, India
| | - Pradeep Das
- Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna, 800007, India
| | - Vahab Ali
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna, 800007, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, EPIP Complex, Hajipur, 844102, India.
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15
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Up-regulation of cytosolic tryparedoxin in Amp B resistant isolates of Leishmania donovani and its interaction with cytosolic tryparedoxin peroxidase. Biochimie 2016; 121:312-25. [DOI: 10.1016/j.biochi.2015.12.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 12/26/2015] [Indexed: 11/18/2022]
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16
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Njogu PM, Guantai EM, Pavadai E, Chibale K. Computer-Aided Drug Discovery Approaches against the Tropical Infectious Diseases Malaria, Tuberculosis, Trypanosomiasis, and Leishmaniasis. ACS Infect Dis 2016; 2:8-31. [PMID: 27622945 DOI: 10.1021/acsinfecdis.5b00093] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Despite the tremendous improvement in overall global health heralded by the adoption of the Millennium Declaration in the year 2000, tropical infections remain a major health problem in the developing world. Recent estimates indicate that the major tropical infectious diseases, namely, malaria, tuberculosis, trypanosomiasis, and leishmaniasis, account for more than 2.2 million deaths and a loss of approximately 85 million disability-adjusted life years annually. The crucial role of chemotherapy in curtailing the deleterious health and economic impacts of these infections has invigorated the search for new drugs against tropical infectious diseases. The research efforts have involved increased application of computational technologies in mainstream drug discovery programs at the hit identification, hit-to-lead, and lead optimization stages. This review highlights various computer-aided drug discovery approaches that have been utilized in efforts to identify novel antimalarial, antitubercular, antitrypanosomal, and antileishmanial agents. The focus is largely on developments over the past 5 years (2010-2014).
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Affiliation(s)
- Peter M. Njogu
- Department of Pharmaceutical Chemistry and ‡Division of Pharmacology, School of Pharmacy, University of Nairobi, P.O. Box 19676-00202, Nairobi, Kenya
- Department of Chemistry, ⊗Institute of Infectious
Disease and Molecular Medicine, and ΘSouth African Medical Research Council Drug
Discovery and Development Research Unit, University of Cape Town, Rondebosch 7701, South Africa
| | - Eric M. Guantai
- Department of Pharmaceutical Chemistry and ‡Division of Pharmacology, School of Pharmacy, University of Nairobi, P.O. Box 19676-00202, Nairobi, Kenya
- Department of Chemistry, ⊗Institute of Infectious
Disease and Molecular Medicine, and ΘSouth African Medical Research Council Drug
Discovery and Development Research Unit, University of Cape Town, Rondebosch 7701, South Africa
| | - Elumalai Pavadai
- Department of Pharmaceutical Chemistry and ‡Division of Pharmacology, School of Pharmacy, University of Nairobi, P.O. Box 19676-00202, Nairobi, Kenya
- Department of Chemistry, ⊗Institute of Infectious
Disease and Molecular Medicine, and ΘSouth African Medical Research Council Drug
Discovery and Development Research Unit, University of Cape Town, Rondebosch 7701, South Africa
| | - Kelly Chibale
- Department of Pharmaceutical Chemistry and ‡Division of Pharmacology, School of Pharmacy, University of Nairobi, P.O. Box 19676-00202, Nairobi, Kenya
- Department of Chemistry, ⊗Institute of Infectious
Disease and Molecular Medicine, and ΘSouth African Medical Research Council Drug
Discovery and Development Research Unit, University of Cape Town, Rondebosch 7701, South Africa
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Dissecting Leishmania infantum Energy Metabolism - A Systems Perspective. PLoS One 2015; 10:e0137976. [PMID: 26367006 PMCID: PMC4569355 DOI: 10.1371/journal.pone.0137976] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 08/24/2015] [Indexed: 01/02/2023] Open
Abstract
Leishmania infantum, causative agent of visceral leishmaniasis in humans, illustrates a complex lifecycle pertaining to two extreme environments, namely, the gut of the sandfly vector and human macrophages. Leishmania is capable of dynamically adapting and tactically switching between these critically hostile situations. The possible metabolic routes ventured by the parasite to achieve this exceptional adaptation to its varying environments are still poorly understood. In this study, we present an extensively reconstructed energy metabolism network of Leishmania infantum as an attempt to identify certain strategic metabolic routes preferred by the parasite to optimize its survival in such dynamic environments. The reconstructed network consists of 142 genes encoding for enzymes performing 237 reactions distributed across five distinct model compartments. We annotated the subcellular locations of different enzymes and their reactions on the basis of strong literature evidence and sequence-based detection of cellular localization signal within a protein sequence. To explore the diverse features of parasite metabolism the metabolic network was implemented and analyzed as a constraint-based model. Using a systems-based approach, we also put forth an extensive set of lethal reaction knockouts; some of which were validated using published data on Leishmania species. Performing a robustness analysis, the model was rigorously validated and tested for the secretion of overflow metabolites specific to Leishmania under varying extracellular oxygen uptake rate. Further, the fate of important non-essential amino acids in L. infantum metabolism was investigated. Stage-specific scenarios of L. infantum energy metabolism were incorporated in the model and key metabolic differences were outlined. Analysis of the model revealed the essentiality of glucose uptake, succinate fermentation, glutamate biosynthesis and an active TCA cycle as driving forces for parasite energy metabolism and its optimal growth. Finally, through our in silico knockout analysis, we could identify possible therapeutic targets that provide experimentally testable hypotheses.
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de Morais CGV, Castro Lima AK, Terra R, dos Santos RF, Da-Silva SAG, Dutra PML. The Dialogue of the Host-Parasite Relationship: Leishmania spp. and Trypanosoma cruzi Infection. BIOMED RESEARCH INTERNATIONAL 2015; 2015:324915. [PMID: 26090399 PMCID: PMC4450238 DOI: 10.1155/2015/324915] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 09/01/2014] [Accepted: 09/02/2014] [Indexed: 01/11/2023]
Abstract
The intracellular protozoa Leishmania spp. and Trypanosoma cruzi and the causative agents of Leishmaniasis and Chagas disease, respectively, belong to the Trypanosomatidae family. Together, these two neglected tropical diseases affect approximately 25 million people worldwide. Whether the host can control the infection or develops disease depends on the complex interaction between parasite and host. Parasite surface and secreted molecules are involved in triggering specific signaling pathways essential for parasite entry and intracellular survival. The recognition of the parasite antigens by host immune cells generates a specific immune response. Leishmania spp. and T. cruzi have a multifaceted repertoire of strategies to evade or subvert the immune system by interfering with a range of signal transduction pathways in host cells, which causes the inhibition of the protective response and contributes to their persistence in the host. The current therapeutic strategies in leishmaniasis and trypanosomiasis are very limited. Efficacy is variable, toxicity is high, and the emergence of resistance is increasingly common. In this review, we discuss the molecular basis of the host-parasite interaction of Leishmania and Trypanosoma cruzi infection and their mechanisms of subverting the immune response and how this knowledge can be used as a tool for the development of new drugs.
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Affiliation(s)
- Carlos Gustavo Vieira de Morais
- Laboratório de Bioquímica de Protozoários e Imunofisiologia do Exercício, Disciplina de Parasitologia, DMIP, FCM, Universidade do Estado do Rio de Janeiro, Avenida Professor Manuel de Abreu 444, Pavilhão Américo Piquet Carneiro, 5° andar, Vila Isabel, 20550-170 Rio de Janeiro, RJ, Brazil
- Programa de Pós Graduação em Microbiologia/FCM/UERJ, Avenida Professor Manuel de Abreu 444, Pavilhão Américo Piquet Carneiro, 3° andar, Vila Isabel, 20550-170 Rio de Janeiro, RJ, Brazil
| | - Ana Karina Castro Lima
- Laboratório de Bioquímica de Protozoários e Imunofisiologia do Exercício, Disciplina de Parasitologia, DMIP, FCM, Universidade do Estado do Rio de Janeiro, Avenida Professor Manuel de Abreu 444, Pavilhão Américo Piquet Carneiro, 5° andar, Vila Isabel, 20550-170 Rio de Janeiro, RJ, Brazil
| | - Rodrigo Terra
- Laboratório de Bioquímica de Protozoários e Imunofisiologia do Exercício, Disciplina de Parasitologia, DMIP, FCM, Universidade do Estado do Rio de Janeiro, Avenida Professor Manuel de Abreu 444, Pavilhão Américo Piquet Carneiro, 5° andar, Vila Isabel, 20550-170 Rio de Janeiro, RJ, Brazil
- Programa de Pós Graduação em Fisiopatologia Clínica e Experimental/FCM/UERJ, Avenida Professor Manuel de Abreu 444, Pavilhão Américo Piquet Carneiro, 5° andar, Vila Isabel, 20550-170 Rio de Janeiro, RJ, Brazil
| | - Rosiane Freire dos Santos
- Programa de Pós Graduação em Microbiologia/FCM/UERJ, Avenida Professor Manuel de Abreu 444, Pavilhão Américo Piquet Carneiro, 3° andar, Vila Isabel, 20550-170 Rio de Janeiro, RJ, Brazil
- Laboratório de Imunofarmacologia Parasitária, Disciplina de Parasitologia, DMIP, FCM, Universidade do Estado do Rio de Janeiro, Avenida Professor Manuel de Abreu 444, Pavilhão Américo Piquet Carneiro, 5° andar, Vila Isabel, 20550-170 Rio de Janeiro, RJ, Brazil
| | - Silvia Amaral Gonçalves Da-Silva
- Laboratório de Imunofarmacologia Parasitária, Disciplina de Parasitologia, DMIP, FCM, Universidade do Estado do Rio de Janeiro, Avenida Professor Manuel de Abreu 444, Pavilhão Américo Piquet Carneiro, 5° andar, Vila Isabel, 20550-170 Rio de Janeiro, RJ, Brazil
| | - Patrícia Maria Lourenço Dutra
- Laboratório de Bioquímica de Protozoários e Imunofisiologia do Exercício, Disciplina de Parasitologia, DMIP, FCM, Universidade do Estado do Rio de Janeiro, Avenida Professor Manuel de Abreu 444, Pavilhão Américo Piquet Carneiro, 5° andar, Vila Isabel, 20550-170 Rio de Janeiro, RJ, Brazil
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Yadav A, Amit A, Chaudhary R, Chandel AS, Mahantesh V, Suman SS, Singh SK, Dikhit MR, Ali V, Rabidas V, Pandey K, Kumar A, Das P, Bimal S. Leishmania donovani: impairment of the cellular immune response against recombinant ornithine decarboxylase protein as a possible evasion strategy of Leishmania in visceral leishmaniasis. Int J Parasitol 2015; 45:33-42. [DOI: 10.1016/j.ijpara.2014.08.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 08/05/2014] [Accepted: 08/07/2014] [Indexed: 01/17/2023]
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Hassan IA, Wang S, Xu L, Yan R, Song X, XiangRui L. Immunological response and protection of mice immunized with plasmid encodingToxoplasma gondiiglycolytic enzyme malate dehydrogenase. Parasite Immunol 2014; 36:674-83. [DOI: 10.1111/pim.12146] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 09/16/2014] [Indexed: 12/31/2022]
Affiliation(s)
- I. A. Hassan
- Key Laboratory of Animal Diseases Diagnosis and Immunology; Ministry of Agriculture; College of Veterinary Medicine; Nanjing Agricultural University; Nanjing Jiangsu China
| | - S. Wang
- Key Laboratory of Animal Diseases Diagnosis and Immunology; Ministry of Agriculture; College of Veterinary Medicine; Nanjing Agricultural University; Nanjing Jiangsu China
| | - L. Xu
- Key Laboratory of Animal Diseases Diagnosis and Immunology; Ministry of Agriculture; College of Veterinary Medicine; Nanjing Agricultural University; Nanjing Jiangsu China
| | - R. Yan
- Key Laboratory of Animal Diseases Diagnosis and Immunology; Ministry of Agriculture; College of Veterinary Medicine; Nanjing Agricultural University; Nanjing Jiangsu China
| | - X. Song
- Key Laboratory of Animal Diseases Diagnosis and Immunology; Ministry of Agriculture; College of Veterinary Medicine; Nanjing Agricultural University; Nanjing Jiangsu China
| | - L. XiangRui
- Key Laboratory of Animal Diseases Diagnosis and Immunology; Ministry of Agriculture; College of Veterinary Medicine; Nanjing Agricultural University; Nanjing Jiangsu China
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Hussain H, Al-Harrasi A, Al-Rawahi A, Green IR, Gibbons S. Fruitful decade for antileishmanial compounds from 2002 to late 2011. Chem Rev 2014; 114:10369-428. [PMID: 25253511 DOI: 10.1021/cr400552x] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Hidayat Hussain
- UoN Chair of Oman's Medicinal Plants and Marine Natural Products, University of Nizwa , P.O. Box 33, Birkat Al Mauz, Nizwa 616, Sultanate of Oman
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Oral azithromycin versus its combination with miltefosine for the treatment of experimental Old World cutaneous leishmaniasis. J Parasit Dis 2014; 40:475-84. [PMID: 27413324 DOI: 10.1007/s12639-014-0529-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 08/12/2014] [Indexed: 01/25/2023] Open
Abstract
Leishmaniasis is one of the neglected infectious diseases included in the World Health Organization's list of the top guns of antimicrobial resistance. Miltefosine is the first and the only available oral effective therapy for leishmaniasis. For fear of its potential resistance, identification of alternative, effective and safe drugs is urgently needed. Therefore, in view of azithromycin promising activity against a number of Leishmania species, this work was carried out to evaluate the efficacy of oral azithromycin alone versus its combination with miltefosine against experimental Old World Cutaneous leishmaniasis thus, can provide another alternative oral therapy or for the first time an oral combination therapy for leishmaniasis. The experiment were carried out on Swiss strain albino mice which were treated either with miltefosine for 20 days, Azithromycin for 20 days or both drugs in combination therapy for shorter duration of 10 days. Efficacy of azithromycin mono and combination therapy with miltefosine was evaluated clinically, parasitologically and by examination of the cutaneous lesions by Transmission Electron Microscopy. The current work demonstrated superior activity of oral azithromycin over oral miltefosine in the treatment of experimentally infected mice with Leishmania major (MHOM/IL/81/FEBNI). Unfortunately, oral combination therapy of azithromycin and miltefosine for short duration though, induced dramatic clinical improvement yet, relapse rapidly developed after cessation of therapy. Oral azithromycin could be a promising oral antileishmanial agent. Further research is recommended to investigate its leishmanicidal activity against other Leishmania species thus; another alternative oral therapy for leishmaniasis can be rapidly available.
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Equbal A, Suman SS, Anwar S, Singh KP, Zaidi A, Sardar AH, Das P, Ali V. Stage-dependent expression and up-regulation of trypanothione synthetase in amphotericin B resistant Leishmania donovani. PLoS One 2014; 9:e97600. [PMID: 24901644 PMCID: PMC4046939 DOI: 10.1371/journal.pone.0097600] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 04/22/2014] [Indexed: 11/27/2022] Open
Abstract
Kinetoplastids differ from other organisms in their ability to conjugate glutathione and spermidine to form trypanothione which is involved in maintaining redox homeostasis and removal of toxic metabolites. It is also involved in drug resistance, antioxidant mechanism, and defense against cellular oxidants. Trypanothione synthetase (TryS) of thiol metabolic pathway is the sole enzyme responsible for the biosynthesis of trypanothione in Leishmania donovani. In this study, TryS gene of L. donovani (LdTryS) was cloned, expressed, and fusion protein purified with affinity column chromatography. The purified protein showed optimum enzymatic activity at pH 8.0–8.5. The TryS amino acids sequences alignment showed that all amino acids involved in catalytic and ligands binding of L. major are conserved in L. donovani. Subcellular localization using digitonin fractionation and immunoblot analysis showed that LdTryS is localized in the cytoplasm. Furthermore, RT-PCR coupled with immunoblot analysis showed that LdTryS is overexpressed in Amp B resistant and stationary phase promastigotes (∼2.0-folds) than in sensitive strain and logarithmic phase, respectively, which suggests its involvement in Amp B resistance. Also, H2O2 treatment upto 150 µM for 8 hrs leads to 2-fold increased expression of LdTryS probably to cope up with oxidative stress generated by H2O2. Therefore, this study demonstrates stage- and Amp B sensitivity-dependent expression of LdTryS in L. donovani and involvement of TryS during oxidative stress to help the parasites survival.
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Affiliation(s)
- Asif Equbal
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, AgamKuan, Patna, India
| | - Shashi Shekhar Suman
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, AgamKuan, Patna, India
| | - Shadab Anwar
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, AgamKuan, Patna, India
| | - Krishn Pratap Singh
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, AgamKuan, Patna, India
| | - Amir Zaidi
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, AgamKuan, Patna, India
| | - Abul Hasan Sardar
- Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences, AgamKuan, Patna, India
| | - Pradeep Das
- Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences, AgamKuan, Patna, India
| | - Vahab Ali
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, AgamKuan, Patna, India
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Bernal FA, Coy-Barrera E. In-silico analyses of sesquiterpene-related compounds on selected Leishmania enzyme-based targets. Molecules 2014; 19:5550-69. [PMID: 24786692 PMCID: PMC6271876 DOI: 10.3390/molecules19055550] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 04/14/2014] [Accepted: 04/22/2014] [Indexed: 01/22/2023] Open
Abstract
A great number of sesquiterpenes are reported in the available literature as good antileishmanial leads. However, their mode of action at the molecular level has not been elucidated. The lack of molecular studies could be considered an impediment for studies seeking to improve sesquiterpene-based drug design. The present in silico study allows us to make important observations about the molecular details of the binding modes of a set of antileishmanial sesquiterpenes against four drug-enzyme targets [pteridine reductase-1 (PTR1), N-myristoyl transferase (NMT), cysteine synthase (CS), trypanothione synthetase (TryS)]. Through molecular docking it was found that two sesquiterpene coumarins are promising leads for the PTR1 and TryS inhibition purposes, and some xanthanolides also exhibited better affinity towards PTR1 and CS binding. In addition, the affinity values were clustered by Principal Component Analysis and drug-like properties were analyzed for the strongest-docking sesquiterpenes. The results are an excellent starting point for future studies of structural optimization of this kind of compounds.
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Affiliation(s)
- Freddy A Bernal
- Laboratorio de Química Bioorgánica, Departamento de Química, Facultad de Ciencias Básicas y Aplicadas, Universidad Militar Nueva Granada, Cundinamarca 250240, AA 49300, Colombia.
| | - Ericsson Coy-Barrera
- Laboratorio de Química Bioorgánica, Departamento de Química, Facultad de Ciencias Básicas y Aplicadas, Universidad Militar Nueva Granada, Cundinamarca 250240, AA 49300, Colombia.
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The double-edged sword in pathogenic trypanosomatids: the pivotal role of mitochondria in oxidative stress and bioenergetics. BIOMED RESEARCH INTERNATIONAL 2014; 2014:614014. [PMID: 24800243 PMCID: PMC3988864 DOI: 10.1155/2014/614014] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 02/17/2014] [Indexed: 11/17/2022]
Abstract
The pathogenic trypanosomatids Trypanosoma brucei, Trypanosoma cruzi, and Leishmania spp. are the causative agents of African trypanosomiasis, Chagas disease, and leishmaniasis, respectively. These diseases are considered to be neglected tropical illnesses that persist under conditions of poverty and are concentrated in impoverished populations in the developing world. Novel efficient and nontoxic drugs are urgently needed as substitutes for the currently limited chemotherapy. Trypanosomatids display a single mitochondrion with several peculiar features, such as the presence of different energetic and antioxidant enzymes and a specific arrangement of mitochondrial DNA (kinetoplast DNA). Due to mitochondrial differences between mammals and trypanosomatids, this organelle is an excellent candidate for drug intervention. Additionally, during trypanosomatids' life cycle, the shape and functional plasticity of their single mitochondrion undergo profound alterations, reflecting adaptation to different environments. In an uncoupling situation, the organelle produces high amounts of reactive oxygen species. However, these species role in parasite biology is still controversial, involving parasite death, cell signalling, or even proliferation. Novel perspectives on trypanosomatid-targeting chemotherapy could be developed based on better comprehension of mitochondrial oxidative regulation processes.
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New chemical scaffolds for human african trypanosomiasis lead discovery from a screen of tyrosine kinase inhibitor drugs. Antimicrob Agents Chemother 2014; 58:2202-10. [PMID: 24468788 DOI: 10.1128/aac.01691-13] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Human African trypanosomiasis (HAT) is caused by the protozoan Trypanosoma brucei. New drugs are needed to treat HAT because of undesirable side effects and difficulties in the administration of the antiquated drugs that are currently used. In human proliferative diseases, protein tyrosine kinase (PTK) inhibitors (PTKIs) have been developed into drugs (e.g., lapatinib and erlotinib) by optimization of a 4-anilinoquinazoline scaffold. Two sets of facts raise a possibility that drugs targeted against human PTKs could be "hits" for antitrypanosomal lead discoveries. First, trypanosome protein kinases bind some drugs, namely, lapatinib, CI-1033, and AEE788. Second, the pan-PTK inhibitor tyrphostin A47 blocks the endocytosis of transferrin and inhibits trypanosome replication. Following up on these concepts, we performed a focused screen of various PTKI drugs as possible antitrypanosomal hits. Lapatinib, CI-1033, erlotinib, axitinib, sunitinib, PKI-166, and AEE788 inhibited the replication of bloodstream T. brucei, with a 50% growth inhibitory concentration (GI50) between 1.3 μM and 2.5 μM. Imatinib had no effect (i.e., GI50>10 μM). To discover leads among the drugs, a mouse model of HAT was used in a proof-of-concept study. Orally administered lapatinib reduced parasitemia, extended the survival of all treated mice, and cured the trypanosomal infection in 25% of the mice. CI-1033 and AEE788 reduced parasitemia and extended the survival of the infected mice. On the strength of these data and noting their oral bioavailabilities, we propose that the 4-anilinoquinazoline and pyrrolopyrimidine scaffolds of lapatinib, CI-1033, and AEE788 are worth optimizing against T. brucei in medicinal chemistry campaigns (i.e., scaffold repurposing) to discover new drugs against HAT.
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Rondon FCM, Bevilaqua CML, Accioly MP, de Morais SM, de Andrade-Júnior HF, de Carvalho CA, Lima JC, Magalhães HCR. In vitro efficacy of Coriandrum sativum, Lippia sidoides and Copaifera reticulata against Leishmania chagasi. ACTA ACUST UNITED AC 2013; 21:185-91. [PMID: 23070424 DOI: 10.1590/s1984-29612012000300002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 05/16/2012] [Indexed: 01/21/2023]
Abstract
The increased incidence of visceral leishmaniasis (VL) in Brazil is due to a lack of effective disease control measures. In addition to that, no effective treatment exists for canine VL in response to synthetic drugs. Thus, the objective of this study was to evaluate the effect of the essential oils of Coriandrum sativum and Lippia sidoides, and oleoresin from Copaifera reticulata, on Leishmania chagasi promastigotes and amastigotes. We also examined the toxicity of these treatments on the murine monocyte cell line RAW 264.7. To determine the IC50 a MTT test (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) was performed on promastigotes, and an in situ ELISA assay was conducted on amastigotes. Here, we demonstrate that oleoresin from C. reticulata was effective against both promastigotes (IC50 of 7.88 µg.mL-1) and amastigotes (IC50 of 0.52 µg.mL-1), and neither of the two treatments differed significantly (p > 0.05) from pentamidine (IC50 of 2.149 µg.mL-1) and amphotericin B (IC50 of 9.754 µg.mL-1). Of the three plant oils tested, only oleoresin showed no toxicity toward monocyte, with 78.45% viability after treatment. Inhibition of promastigote and amastigote growth and the lack of cytotoxicity by C. reticulata demonstrate that oleoresin may be a viable option for analyzing the in vivo therapeutic effects of leishmanicidal plants.
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Heparin modulates the endopeptidase activity of Leishmania mexicana cysteine protease cathepsin L-Like rCPB2.8. PLoS One 2013; 8:e80153. [PMID: 24278253 PMCID: PMC3836952 DOI: 10.1371/journal.pone.0080153] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Accepted: 09/28/2013] [Indexed: 11/19/2022] Open
Abstract
Background Cysteine protease B is considered crucial for the survival and infectivity of the Leishmania in its human host. Several microorganism pathogens bind to the heparin-like glycosaminoglycans chains of proteoglycans at host-cell surface to promote their attachment and internalization. Here, we have investigated the influence of heparin upon Leishmania mexicana cysteine protease rCPB2.8 activity. Methodology/Principal Findings The data analysis revealed that the presence of heparin affects all steps of the enzyme reaction: (i) it decreases 3.5-fold the k1 and 4.0-fold the k−1, (ii) it affects the acyl-enzyme accumulation with pronounced decrease in k2 (2.7-fold), and also decrease in k3 (3.5-fold). The large values of ΔG = 12 kJ/mol for the association and dissociation steps indicate substantial structural strains linked to the formation/dissociation of the ES complex in the presence of heparin, which underscore a conformational change that prevents the diffusion of substrate in the rCPB2.8 active site. Binding to heparin also significantly decreases the α-helix content of the rCPB2.8 and perturbs the intrinsic fluorescence emission of the enzyme. The data strongly suggest that heparin is altering the ionization of catalytic (Cys25)-S−/(His163)-Im+ H ion pair of the rCPB2.8. Moreover, the interaction of heparin with the N-terminal pro-region of rCPB2.8 significantly decreased its inhibitory activity against the mature enzyme. Conclusions/Significance Taken together, depending on their concentration, heparin-like glycosaminoglycans can either stimulate or antagonize the activity of cysteine protease B enzymes during parasite infection, suggesting that this glycoconjugate can anchor parasite cysteine protease at host cell surface.
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de Almeida Nogueira NP, Morgado-Díaz JA, Menna-Barreto RFS, Paes MC, da Silva-López RE. Effects of a marine serine protease inhibitor on viability and morphology of Trypanosoma cruzi, the agent of Chagas disease. Acta Trop 2013; 128:27-35. [PMID: 23770204 DOI: 10.1016/j.actatropica.2013.05.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 04/10/2013] [Accepted: 05/21/2013] [Indexed: 01/04/2023]
Abstract
It has been reported that serine peptidase activities of Trypanosoma cruzi play crucial roles in parasite dissemination and host cell invasion and therefore their inhibition could affect the progress of Chagas disease. The present study investigates the interference of the Stichodactyla helianthus Kunitz-type serine protease inhibitor (ShPI-I), a 55-amino acid peptide, in T. cruzi serine peptidase activities, parasite viability, and parasite morphology. The effect of this peptide was also studied in Leishmania amazonensis promastigotes and it was proved to be a powerful inhibitor of serine proteases activities and the parasite viability. The ultrastructural alterations caused by ShPI-I included vesiculation of the flagellar pocket membrane and the appearance of a cytoplasmic vesicle that resembles an autophagic vacuole. ShPI-I, which showed itself to be an important T. cruzi serine peptidase inhibitor, reduced the parasite viability, in a dose and time dependent manner. The maximum effect of peptide on T. cruzi viability was observed when ShPI-I at 1×10(-5)M was incubated for 24 and 48h which killed completely both metacyclic trypomastigote and epimastigote forms. At 1×10(-6)M ShPI-I, in the same periods of time, reduced parasite viability about 91-95% respectively. Ultrastructural analysis demonstrated the formation of concentric membranar structures especially in the cytosol, involving organelles and small vesicles. Profiles of endoplasmic reticulum were also detected, surrounding cytosolic vesicles that resembled autophagic vacuoles. These results suggest that serine peptidases are important in T. cruzi physiology since the inhibition of their activity killed parasites in vitro as well as inducing important morphological alterations. Protease inhibitors thus appear to have a potential role as anti-trypanosomatidal agents.
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Affiliation(s)
- Natália Pereira de Almeida Nogueira
- Laboratório de Interação de Tripanosomatídeos e Vetores, Departamento de Bioquímica, Instituto de Biologia Roberto Alcântara Gomes, Universidade do Estado do Rio de Janeiro, UERJ, Rio de Janeiro, RJ, Brazil
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Target-based drug discovery for human African trypanosomiasis: selection of molecular target and chemical matter. Parasitology 2013; 141:28-36. [PMID: 23931634 PMCID: PMC3884840 DOI: 10.1017/s0031182013001017] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Target-based approaches for human African trypanosomiasis (HAT) and related parasites can be a valuable route for drug discovery for these diseases. However, care needs to be taken in selection of both the actual drug target and the chemical matter that is developed. In this article, potential criteria to aid target selection are described. Then the physiochemical properties of typical oral drugs are discussed and compared to those of known anti-parasitics.
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31
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Giannese F, Berg M, Van der Veken P, Castagna V, Tornaghi P, Augustyns K, Degano M. Structures of purine nucleosidase from Trypanosoma brucei bound to isozyme-specific trypanocidals and a novel metalorganic inhibitor. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2013; 69:1553-66. [PMID: 23897478 DOI: 10.1107/s0907444913010792] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Accepted: 04/20/2013] [Indexed: 11/11/2022]
Abstract
Sleeping sickness is a deadly disease that primarily affects sub-Saharan Africa and is caused by protozoan parasites of the Trypanosoma genus. Trypanosomes are purine auxotrophs and their uptake pathway has long been appreciated as an attractive target for drug design. Recently, one tight-binding competitive inhibitor of the trypanosomal purine-specific nucleoside hydrolase (IAGNH) showed remarkable trypanocidal activity in a murine model of infection. Here, the enzymatic characterization of T. brucei brucei IAGNH is presented, together with its high-resolution structures in the unliganded form and in complexes with different inhibitors, including the trypanocidal compound UAMC-00363. A description of the crucial contacts that account for the high-affinity inhibition of IAGNH by iminoribitol-based compounds is provided and the molecular mechanism underlying the conformational change necessary for enzymatic catalysis is identified. It is demonstrated for the first time that metalorganic complexes can compete for binding at the active site of nucleoside hydrolase enzymes, mimicking the positively charged transition state of the enzymatic reaction. Moreover, we show that divalent metal ions can act as noncompetitive IAGNH inhibitors, stabilizing a nonproductive conformation of the catalytic loop. These results open a path for rational improvement of the potency and the selectivity of existing compounds and suggest new scaffolds that may be used as blueprints for the design of novel antitrypanosomal compounds.
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Affiliation(s)
- Francesca Giannese
- Biocrystallography Unit, Department of Immunology, Transplantation and Infectious Diseases, Scientific Institute San Raffaele, via Olgettina 58, 20132 Milano, Italy
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In-silico Leishmania target selectivity of antiparasitic terpenoids. Molecules 2013; 18:7761-847. [PMID: 23823876 PMCID: PMC6270436 DOI: 10.3390/molecules18077761] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 06/23/2013] [Accepted: 06/26/2013] [Indexed: 01/21/2023] Open
Abstract
Neglected Tropical Diseases (NTDs), like leishmaniasis, are major causes of mortality in resource-limited countries. The mortality associated with these diseases is largely due to fragile healthcare systems, lack of access to medicines, and resistance by the parasites to the few available drugs. Many antiparasitic plant-derived isoprenoids have been reported, and many of them have good in vitro activity against various forms of Leishmania spp. In this work, potential Leishmania biochemical targets of antiparasitic isoprenoids were studied in silico. Antiparasitic monoterpenoids selectively docked to L. infantum nicotinamidase, L. major uridine diphosphate-glucose pyrophosphorylase and methionyl t-RNA synthetase. The two protein targets selectively targeted by germacranolide sesquiterpenoids were L. major methionyl t-RNA synthetase and dihydroorotate dehydrogenase. Diterpenoids generally favored docking to L. mexicana glycerol-3-phosphate dehydrogenase. Limonoids also showed some selectivity for L. mexicana glycerol-3-phosphate dehydrogenase and L. major dihydroorotate dehydrogenase while withanolides docked more selectively with L. major uridine diphosphate-glucose pyrophosphorylase. The selectivity of the different classes of antiparasitic compounds for the protein targets considered in this work can be explored in fragment- and/or structure-based drug design towards the development of leads for new antileishmanial drugs.
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Crystal structure of Cryptosporidium parvum pyruvate kinase. PLoS One 2012; 7:e46875. [PMID: 23056503 PMCID: PMC3467265 DOI: 10.1371/journal.pone.0046875] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 09/10/2012] [Indexed: 12/24/2022] Open
Abstract
Pyruvate kinase plays a critical role in cellular metabolism of glucose by serving as a major regulator of glycolysis. This tetrameric enzyme is allosterically regulated by different effector molecules, mainly phosphosugars. In response to binding of effector molecules and substrates, significant structural changes have been identified in various pyruvate kinase structures. Pyruvate kinase of Cryptosporidium parvum is exceptional among known enzymes of protozoan origin in that it exhibits no allosteric property in the presence of commonly known effector molecules. The crystal structure of pyruvate kinase from C. parvum has been solved by molecular replacement techniques and refined to 2.5 Å resolution. In the active site a glycerol molecule is located near the γ-phosphate site of ATP, and the protein structure displays a partially closed active site. However, unlike other structures where the active site is closed, the α6' helix in C. parvum pyruvate kinase unwinds and assumes an extended conformation. In the crystal structure a sulfate ion is found at a site that is occupied by a phosphate of the effector molecule in many pyruvate kinase structures. A new feature of the C. parvum pyruvate kinase structure is the presence of a disulfide bond cross-linking the two monomers in the asymmetric unit. The disulfide bond is formed between cysteine residue 26 in the short N-helix of one monomer with cysteine residue 312 in a long helix (residues 303-320) of the second monomer at the interface of these monomers. Both cysteine residues are unique to C. parvum, and the disulfide bond remained intact in a reduced environment. However, the significance of this bond, if any, remains unknown at this time.
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Dihydrofolate reductase as a therapeutic target for infectious diseases: opportunities and challenges. Future Med Chem 2012; 4:1335-65. [DOI: 10.4155/fmc.12.68] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Infectious diseases caused by parasites continue to take a massive toll on human health in the poor regions of the world. Filling the anti-infective drug-discovery pipeline has never been as challenging as it is now. The organisms responsible for these diseases have interesting biology with many potential biochemical targets. Inhibition of metabolic enzymes has been established as an attractive strategy for anti-infectious drug development. In this field, dihydrofolate reductase (DHFR) is an important enzyme in nucleic and amino acid synthesis and an extensively studied drug target over the past 50 years. The challenges for novel DHFR inhibition-based chemotherapeutics for the treatment of infectious diseases are now focused on overcoming the resistance problem as well as cost–effectiveness. Each year, the large number of literature citations attest the continued popularity of DHFR. It becomes truly the ‘enzyme of choice for all seasons and almost all reasons’. Herein, we summarize the opportunities and challenges in developing novel lead based on this target.
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Eissa MM, Amer EI, El Sawy SM. Leishmania major: Activity of tamoxifen against experimental cutaneous leishmaniasis. Exp Parasitol 2011; 128:382-90. [DOI: 10.1016/j.exppara.2011.05.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Revised: 05/11/2011] [Accepted: 05/12/2011] [Indexed: 10/18/2022]
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Gomes MR, Guimarães ACR, de Miranda AB. Specific and nonhomologous isofunctional enzymes of the genetic information processing pathways as potential therapeutical targets for tritryps. Enzyme Res 2011; 2011:543912. [PMID: 21808726 PMCID: PMC3145330 DOI: 10.4061/2011/543912] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2011] [Revised: 03/22/2011] [Accepted: 05/05/2011] [Indexed: 12/03/2022] Open
Abstract
Leishmania major, Trypanosoma brucei, and Trypanosoma cruzi (Tritryps) are unicellular protozoa that cause leishmaniasis, sleeping sickness and Chagas' disease, respectively. Most drugs against them were discovered through the screening of large numbers of compounds against whole parasites. Nonhomologous isofunctional enzymes (NISEs) may present good opportunities for the identification of new putative drug targets because, though sharing the same enzymatic activity, they possess different three-dimensional structures thus allowing the development of molecules against one or other isoform. From public data of the Tritryps' genomes, we reconstructed the Genetic Information Processing Pathways (GIPPs). We then used AnEnPi to look for the presence of these enzymes between Homo sapiens and Tritryps, as well as specific enzymes of the parasites. We identified three candidates (ECs 3.1.11.2 and 6.1.1.-) in these pathways that may be further studied as new therapeutic targets for drug development against these parasites.
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Affiliation(s)
- Monete Rajão Gomes
- Laboratório de Biologia Computacional e Sistemas, Instituto Oswaldo Cruz/FIOCRUZ, 21045-900 Rio de Janeiro, RJ, Brazil
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Merlino A, Otero L, Gambino D, Laura Coitiño E. In search of patterns over physicochemical properties and pharmacological activities for a set of [MCl2(thiosemicarbazone)] complexes (M=Pt/Pd): Support for multiple mechanisms of antichagasic action excluding DNA-bonding in vivo? Eur J Med Chem 2011; 46:2639-51. [DOI: 10.1016/j.ejmech.2011.03.046] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 03/14/2011] [Accepted: 03/22/2011] [Indexed: 01/10/2023]
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Chawla B, Madhubala R. Drug targets in Leishmania. J Parasit Dis 2010; 34:1-13. [PMID: 21526026 DOI: 10.1007/s12639-010-0006-3] [Citation(s) in RCA: 131] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Accepted: 06/22/2010] [Indexed: 02/03/2023] Open
Abstract
Leishmaniasis is a major public health problem and till date there are no effective vaccines available. The control strategy relies solely on chemotherapy of the infected people. However, the present repertoire of drugs is limited and increasing resistance towards them has posed a major concern. The first step in drug discovery is to identify a suitable drug target. The genome sequences of Leishmania major and Leishmania infantum has revealed immense amount of information and has given the opportunity to identify novel drug targets that are unique to these parasites. Utilization of this information in order to come up with a candidate drug molecule requires combining all the technology and using a multi-disciplinary approach, right from characterizing the target protein to high throughput screening of compounds. Leishmania belonging to the order kinetoplastidae emerges from the ancient eukaryotic lineages. They are quite diverse from their mammalian hosts and there are several cellular processes that we are getting to know of, which exist distinctly in these parasites. In this review, we discuss some of the metabolic pathways that are essential and could be used as potential drug targets in Leishmania.
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Affiliation(s)
- Bhavna Chawla
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
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Ommen G, Chrobak M, Clos J. The co-chaperone SGT of Leishmania donovani is essential for the parasite's viability. Cell Stress Chaperones 2010; 15:443-55. [PMID: 19953351 PMCID: PMC3082645 DOI: 10.1007/s12192-009-0160-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Revised: 10/30/2009] [Accepted: 11/11/2009] [Indexed: 10/20/2022] Open
Abstract
Molecular chaperone proteins play a pivotal role in the protozoan parasite Leishmania donovani, controlling cell fate and ensuring intracellular survival. In higher eukaryotes, the so-called co-chaperone proteins are required for client protein recognition and proper function of chaperones, among them the small glutamine-rich tetratricopeptide repeat proteins (SGT) which interact with both HSP70 and HSP90 chaperones. An atypical SGT homolog is found in the L. donovani genome, encoding a protein lacking the C-terminal glutamine-rich region, normally typical for SGT family members. The gene is expressed constitutively during the life cycle and is essential for survival and/or growth of the parasites. LdSGT forms large, stable complexes that also include another putative co-chaperone, HSC70 interacting protein (HIP). The gene product forms cytoplasmic clusters, matching the subcellular distribution of HIP and partly that of the major cytoplasmic chaperones, HSP70 and HSP90, reflecting a direct molecular interaction with both chaperones.
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Affiliation(s)
- Gabi Ommen
- Bernhard Nocht Institute for Tropical Medicine, Bernhard Nocht St. 74, 20359 Hamburg, Germany
| | - Mareike Chrobak
- Bernhard Nocht Institute for Tropical Medicine, Bernhard Nocht St. 74, 20359 Hamburg, Germany
| | - Joachim Clos
- Bernhard Nocht Institute for Tropical Medicine, Bernhard Nocht St. 74, 20359 Hamburg, Germany
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Roberts CW, Henriquez FL. Drug target identification, validation, characterisation and exploitation for treatment of Acanthamoeba (species) infections. Exp Parasitol 2009; 126:91-6. [PMID: 20035751 DOI: 10.1016/j.exppara.2009.11.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2009] [Revised: 11/19/2009] [Accepted: 11/30/2009] [Indexed: 12/15/2022]
Abstract
New more efficacious antimicrobials as required for the treatment of Acanthamoeba infections as those currently available require arduous treatment regimes, are not always effective and are poorly active against the cystic stages. Herein, we review potential drug targets including tubulin, alternative oxidase, amino acid biosynthesis and myosin. In addition, we review the literature for current missing tools and resources for the identification, validation and development of new antimicrobials for this organism. Additional targets should come to light through a concerted genome sequencing effort.
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Affiliation(s)
- Craig W Roberts
- Strathclyde Institute for Pharmacy & Biomedical Sciences, University of Strathclyde, Glasgow G4 0NR, UK
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Cavalli A, Bolognesi ML. Neglected Tropical Diseases: Multi-Target-Directed Ligands in the Search for Novel Lead Candidates against Trypanosoma and Leishmania. J Med Chem 2009; 52:7339-59. [DOI: 10.1021/jm9004835] [Citation(s) in RCA: 172] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Andrea Cavalli
- Department of Pharmaceutical Sciences, Alma Mater Studiorum, University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy
- Department of Drug Discovery and Development, Italian Institute of Technology, Via Morego 30, 16163 Genova, Italy
| | - Maria Laura Bolognesi
- Department of Pharmaceutical Sciences, Alma Mater Studiorum, University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy
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Structural analysis of trypanosomal sirtuin: an insight for selective drug design. Mol Divers 2009; 14:169-78. [DOI: 10.1007/s11030-009-9147-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Accepted: 03/27/2009] [Indexed: 10/27/2022]
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Murta SMF, Vickers TJ, Scott DA, Beverley SM. Methylene tetrahydrofolate dehydrogenase/cyclohydrolase and the synthesis of 10-CHO-THF are essential in Leishmania major. Mol Microbiol 2009; 71:1386-401. [PMID: 19183277 PMCID: PMC2692627 DOI: 10.1111/j.1365-2958.2009.06610.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
10-Formyl tetrahydrofolate (10-CHO-THF) is a key metabolite in C1 carbon metabolism, arising through the action of formate-tetrahydrofolate ligase (FTL) and/or 5,10-methenyltetrahydrofolate cyclohydrolase/5,10-methylene tetrahydrofolate dehydrogenase (DHCH). Leishmania major possesses single DHCH1 and FTL genes encoding exclusively cytosolic proteins, unlike other organisms where isoforms occur in the mitochondrion as well. Recombinant DHCH1 showed typical NADP(+)-dependent methylene tetrahydrofolate DH and 5,10-methenyltetrahydrofolate CH activities, and the DH activity was potently inhibited by a substrate analogue 5,10-CO-THF (K(i) 105 nM), as was Leishmania growth (EC(50) 1.1 microM). Previous studies showed null ftl(-) mutants were normal, raising the possibility that loss of the purine synthetic pathway had rendered 10-CHO-THF dispensable in evolution. We were unable to generate dhch1(-) null mutants by gene replacement, despite using a wide spectrum of nutritional supplements expected to bypass DHCH function. We applied an improved method for testing essential genes in Leishmania, based on segregational loss of episomal complementing genes rather than transfection; analysis of approximately 1400 events without successful loss of DHCH1 again established its requirement. Lastly, we employed 'genetic metabolite complementation' using ectopically expressed FTL as an alternative source of 10-CHO-THF; now dhch1(-) null parasites were readily obtained. These data establish a requirement for 10-CHO-THF metabolism in L. major, and provide genetic and pharmacological validation of DHCH as a target for chemotherapy, in this and potentially other protozoan parasites.
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Affiliation(s)
| | | | | | - Stephen M. Beverley
- Department of Molecular Microbiology, Box 8230, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA
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Antiparasitic chemotherapy: tinkering with the purine salvage pathway. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 625:116-32. [PMID: 18365663 DOI: 10.1007/978-0-387-77570-8_10] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Distinguishable differences between infectine organisms and their respective hosts with respect to metabolism and macromolecular structure provide scopes for detailed characterization of target proteins and/or macromolecules as the focus for the development of selective inhibitors. In order to develop a rational approach to antiparasitic chemotherapy, finding differences in the biochemical pathways of the parasite with respect to the host it infects is therefore of primary importance. Like most parasitic protozoan, the genus Leishmania is an obligate auxotroph of purines and hence for requirement of purine bases depends on its own purine salvage pathways. Among various purine acquisition routes used by the parasite, the pathway involved in assimilation of adenosine nucleotide is unique and differs significantly in the extracellular form of the parasite (promastigotes) from its corresponding intracellular form (amastigotes). Adenosine kinase (AdK) is the gateway enzyme of this pathway and displays stage-specific activity pattern. Therefore, understanding the catalytic mechanism of the enzyme, its structural complexities and mode of its regulation have emerged as one of the major areas of investigation. This review, in general, discusses possible strategies to validate several purine salvage enzymes as targets for chemotherapeutic manipulation with special reference to adenosine kinase of Leishmania donovani. Systemic endotheliosis, commonly known as Kala-azar in India, is caused by the parasitic protozoon Leishmania donovani. The spread of leishmaniases follows the distribution of these vectors in the temperate, tropical and subtropical regions of the world leading to loss of thousands of human lives.' WHO has declared leishmaniasis among one of the six major diseases namely leishmaniasis, malaria, amoebiasis, filariasis, Chagas disease and schistosomiasis in its Special Programme for Research and Training in Tropical Diseases. Strategies for better prophylaxis and urgent therapies must be therefore devised to control this menace among poor and under privileged population. However, the possible availability of antiparasitic vaccines appears remote in near future. Therefore, chemotherapy remains the mainstay for the treatment of most parasitic diseases. Selectivity of an antiparasitic compound must depend upon its mode of specific inhibition of parasite replication leaving host processes unaffected. In principle, these agents are expected to exert their selective actions against growth of the invading organisms by having one or both of the following properties: (i) Selective activation of compounds in question by enzyme (s) from the invading organisms, which are not present in the uninfected cells. (ii) Selective inhibition of vital enzyme(s), which are essential for replication of the parasites. In order to design specific compounds with the above characteristics, it is essential to have a thorough knowledge of the properties of the enzyme(s) and/or macromolecules which are unique to the parasite. Phylogenetic studies suggested that trypanosomatid parasites are relatively early-branching eukaryotic cells and indeed their cellular organization differs considerably from their mammalian hosts counterpart. Various enzymes, metabolites or proteins identified in parasites and known to be absent from or strikingly different in the mammalian hosts were considered as ideal drug targets. Among the various metabolic pathways that are presently being studied for their prospects to be exploited as the target for chemotherapeutic manipulation, the most important are (i) purine salvage (ii) polyamine and thiol metabolism (iii) folate biosynthesis (iv) DNA replication (v) glycolytic and (vi) fatty acid biosynthetic pathways etc. A number of excellent reviews, describing the prospects and efficacies of these pathways, already exist in the literature. Our laboratory is engaged in studying the pathways responsible for synthesis and assimilation ofpurine nucleotides in the parasitic protozoon Leishmania donovani. Therefore, we shall, for the constraint of space, try to restrict the discussion mostly with the purine salvage pathways of various Leishmania parasites with particular reference to the unique features of one of the enzymes of the purine salvage pathway viz AdK and its prospects as the chemotherapeutic target. However, contributions of other workers will also be discussed whenever essential and analogy will be drawn in order to make the reading coherent. The Leishmania genus goes through a dimorphic life cycle. It exists as a promastigote (extracellular form) in the sand fly vector but is converted to an amastigote (intracellular form) upon entry into mammalian macrophages. During this transformation process, the activities of a large number of proteins and/or enzymes have been reported to be stage-specifically altered and hence they could be prospective targets for development of chemotherapeutic regimen based on the exploitable differences of the parasitic proteins from their respective host counterpart.
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da Silva-Lopez RE, Morgado-Díaz JA, dos Santos PT, Giovanni-De-Simone S. Purification and subcellular localization of a secreted 75 kDa Trypanosoma cruzi serine oligopeptidase. Acta Trop 2008; 107:159-67. [PMID: 18599007 DOI: 10.1016/j.actatropica.2008.05.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2007] [Revised: 05/20/2008] [Accepted: 05/22/2008] [Indexed: 11/17/2022]
Abstract
An extracellular serine peptidase was purified 460-fold from Trypanosoma cruzi epimastigotes culture supernatant with (NH(4))(2)SO(4) precipitation followed by affinity chromatography aprotinin-agarose and continuous elution electrophoresis, yielding a total recovery of 65%. The molecular mass of the active enzyme estimated by reducing and non-reducing SDS-PAGE was about 75kDa. The optimal pH and temperature of this glycosylated peptidase were 8.0 and 37 degrees C using alpha-N-rho-tosyl-L-arginine-methyl ester (L-TAME) as substrate. The enzyme did not hydrolyze polypeptide substrates but was active against short peptide substrates containing arginine at the P1 site, in both ester and amide bonds. The peptidase was inhibited by TPCK and TCLK but not by other protease inhibitors suggesting that the enzyme belongs to the serine peptidase class. Interestingly, the enzyme seems to demonstrate some metal dependence since its activity was reduced by 1,10-phenanthroline, calcium and zinc ions. Rabbit anti-T. cruzi extracellular serine peptidase antiserum was used to show that the enzyme was restricted to intracellular structures, including the flagellar pocket, plasma membrane and cytoplasmic vesicles resembling reservosomes. These results suggest that the serine oligopeptidase is secreted into the extracellular environment through the flagellar pocket and the intracellular location could suggest its participation in certain proteolysis events in reservosomes. These findings show that this peptidase is a novel T. cruzi serine oligopeptidase, which differs not only from other peptidases described in the same parasite but also in other species of Trypanosoma.
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Ogbunugafo H, Okochi V, Okpuzor J, Odesanmi O, Ebigwe F. The Butanol Extract of Mitragyna ciliata Root: Potential as a Trypanocide. INT J PHARMACOL 2008. [DOI: 10.3923/ijp.2008.102.107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Jhingran A, Padmanabhan PK, Singh S, Anamika K, Bakre AA, Bhattacharya S, Bhattacharya A, Srinivasan N, Madhubala R. Characterization of the Entamoeba histolytica ornithine decarboxylase-like enzyme. PLoS Negl Trop Dis 2008; 2:e115. [PMID: 18235846 PMCID: PMC2217671 DOI: 10.1371/journal.pntd.0000115] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2007] [Accepted: 10/04/2007] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND The polyamines putrescine, spermidine, and spermine are organic cations that are required for cell growth and differentiation. Ornithine decarboxylase (ODC), the first and rate-limiting enzyme in the polyamine biosynthetic pathway, is a highly regulated enzyme. METHODOLOGY AND RESULTS To use this enzyme as a potential drug target, the gene encoding putative ornithine decarboxylase (ODC)-like sequence was cloned from Entamoeba histolytica, a protozoan parasite causing amoebiasis. DNA sequence analysis revealed an open reading frame (ORF) of approximately 1,242 bp encoding a putative protein of 413 amino acids with a calculated molecular mass of 46 kDa and a predicted isoelectric point of 5.61. The E. histolytica putative ODC-like sequence has 33% sequence identity with human ODC and 36% identity with the Datura stramonium ODC. The ORF is a single-copy gene located on a 1.9-Mb chromosome. The recombinant putative ODC protein (48 kDa) from E. histolytica was heterologously expressed in Escherichia coli. Antiserum against recombinant putative ODC protein detected a band of anticipated size approximately 46 kDa in E. histolytica whole-cell lysate. Difluoromethylornithine (DFMO), an enzyme-activated irreversible inhibitor of ODC, had no effect on the recombinant putative ODC from E. histolytica. Comparative modeling of the three-dimensional structure of E. histolytica putative ODC shows that the putative binding site for DFMO is disrupted by the substitution of three amino acids-aspartate-332, aspartate-361, and tyrosine-323-by histidine-296, phenylalanine-305, and asparagine-334, through which this inhibitor interacts with the protein. Amino acid changes in the pocket of the E. histolytica enzyme resulted in low substrate specificity for ornithine. It is possible that the enzyme has evolved a novel substrate specificity. CONCLUSION To our knowledge this is the first report on the molecular characterization of putative ODC-like sequence from E. histolytica. Computer modeling revealed that three of the critical residues required for binding of DFMO to the ODC enzyme are substituted in E. histolytica, resulting in the likely loss of interactions between the enzyme and DFMO.
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Affiliation(s)
- Anupam Jhingran
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | | | - Sushma Singh
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Krishanpal Anamika
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Abhijeet A. Bakre
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Sudha Bhattacharya
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Alok Bhattacharya
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | | | - Rentala Madhubala
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
- * E-mail:
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Pinney JW, Papp B, Hyland C, Wambua L, Westhead DR, McConkey GA. Metabolic reconstruction and analysis for parasite genomes. Trends Parasitol 2007; 23:548-54. [PMID: 17950669 DOI: 10.1016/j.pt.2007.08.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Revised: 08/20/2007] [Accepted: 08/20/2007] [Indexed: 01/29/2023]
Abstract
With the completion of sequencing projects for several parasite genomes, efforts are ongoing to make sense of this mass of information in terms of the gene products encoded and their interactions in the growth, development and survival of parasites. The emerging science of systems biology aims to explain the complex relationship between genotype and phenotype by using network models. One area in which this approach has been particularly successful is in the modeling of metabolism. With an accurate picture of the set of metabolic reactions encoded in a genome, it is now possible to identify enzymes or transporters that might be viable targets for new drugs. Because these predictions greatly depend on the quality and completeness of the genome annotation, there are substantial efforts in the scientific community to increase the numbers of metabolic enzymes identified. In this review, we discuss the opportunities for using metabolic reconstruction and analysis tools in parasitology research, and their applications to protozoan parasites.
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Affiliation(s)
- John W Pinney
- Faculty of Life Sciences, The University of Manchester, Oxford Road, Manchester, UK
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Human African trypanosomiasis: pharmacological re-engagement with a neglected disease. Br J Pharmacol 2007; 152:1155-71. [PMID: 17618313 DOI: 10.1038/sj.bjp.0707354] [Citation(s) in RCA: 221] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
This review discusses the challenges of chemotherapy for human African trypanosomiasis (HAT). The few drugs registered for use against the disease are unsatisfactory for a number of reasons. HAT has two stages. In stage 1 the parasites proliferate in the haemolymphatic system. In stage 2 they invade the central nervous system and brain provoking progressive neurological dysfunction leading to symptoms that include the disrupted sleep wake patterns that give HAT its more common name of sleeping sickness. Targeting drugs to the central nervous system offers many challenges. However, it is the cost of drug development for diseases like HAT, that afflict exclusively people of the world's poorest populations, that has been the principal barrier to new drug development and has led to them becoming neglected. Here we review drugs currently registered for HAT, and also discuss the few compounds progressing through clinical trials. Finally we report on new initiatives that might allow progress to be made in developing new and satisfactory drugs for this terrible disease.
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