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Ungogo MA, de Koning HP. Drug resistance in animal trypanosomiases: Epidemiology, mechanisms and control strategies. Int J Parasitol Drugs Drug Resist 2024; 25:100533. [PMID: 38555795 PMCID: PMC10990905 DOI: 10.1016/j.ijpddr.2024.100533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 03/13/2024] [Accepted: 03/15/2024] [Indexed: 04/02/2024]
Abstract
Animal trypanosomiasis (AT) is a complex of veterinary diseases known under various names such as nagana, surra, dourine and mal de caderas, depending on the country, the infecting trypanosome species and the host. AT is caused by parasites of the genus Trypanosoma, and the main species infecting domesticated animals are T. brucei brucei, T. b. rhodesiense, T. congolense, T. simiae, T. vivax, T. evansi and T. equiperdum. AT transmission, again depending on species, is through tsetse flies or common Stomoxys and tabanid flies or through copulation. Therefore, the geographical spread of all forms of AT together is not restricted to the habitat of a single vector like the tsetse fly and currently includes almost all of Africa, and most of South America and Asia. The disease is a threat to millions of companion and farm animals in these regions, creating a financial burden in the billions of dollars to developing economies as well as serious impacts on livestock rearing and food production. Despite the scale of these impacts, control of AT is neglected and under-resourced, with diagnosis and treatments being woefully inadequate and not improving for decades. As a result, neither the incidence of the disease, nor the effectiveness of treatment is documented in most endemic countries, although it is clear that there are serious issues of resistance to the few old drugs that are available. In this review we particularly look at the drugs, their application to the various forms of AT, and their mechanisms of action and resistance. We also discuss the spread of veterinary trypanocide resistance and its drivers, and highlight current and future strategies to combat it.
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Affiliation(s)
- Marzuq A Ungogo
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom; School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Harry P de Koning
- School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom.
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Rogers I, Berg K, Ramirez H, Hovel-Miner GA. Fexinidazole induced cytotoxicity is distinct from related anti-trypanosome nitroaromatic drugs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.09.561529. [PMID: 37873123 PMCID: PMC10592674 DOI: 10.1101/2023.10.09.561529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Nitroaromatic drugs are of critical importance for the treatment of trypanosome infections in Africa and the Americas. Fexinidazole recently joined benznidazole and nifurtimox in this family when it was approved as the first oral therapy against Human African trypanosomiasis (HAT). Nitroaromatic prodrugs are bioactivated by the trypanosome-specific type I nitroreductase (NTR) enzyme that renders the compounds trypanocidal. A caveat to the specificity of NTR activation is the potential for drug resistance and cross-resistance that can arise if NTR expression or functionality is altered through mutation. The outcomes of NTR bioactivation of nitroaromatic compounds is variable but can include the formation highly reactive open chain nitriles that can damage biomolecules including DNA. A proposed mechanism of action of nitroaromatic compounds is the formation of reactive oxygen species (ROS) resulting in the formation of trypanocidal levels of DNA damage. Fexinidazole made its way to clinical approval without a significant interrogation of its effects on trypanosome biology and a limited understanding of its mechanism of action. Early reports mentioned fexinidazole potentially affects DNA synthesis but without supporting data. In this study, we evaluated and compared the cytotoxic effects of nifurtimox, benznidazole, and fexinidazole on Trypanosoma brucei using in vitro analyses. Specifically, we sought to differentiate between the proposed effects of nitroaromatics on DNA damage and DNA synthesis. Toward this goal we generated a novel γH2A-based flow cytometry assay that reports DNA damage formation in conjunction with cell cycle progression. Here we report that fexinidazole's cytotoxic outcomes are distinct from the related drugs nifurtimox and benznidazole. Specifically, we show that fexinidazole treatment results in a pronounced defect in DNA synthesis that reduces the population of parasites in S phase. In contrast, treatment with nifurtimox and benznidazole appear accumulate DNA damage early in cell cycle and result in a defective G 2 population. The findings presented here bring us closer to understanding the anti-trypanosomatid mechanisms of action of nitroaromatic compounds, which will promote improved drug design and help combat potential drug resistance in the future. Our findings also highlight DNA synthesis inhibition as a powerful anti-parasitic drug target.
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da Costa KM, Valente RDC, da Fonseca LM, Freire-de-Lima L, Previato JO, Mendonça-Previato L. The History of the ABC Proteins in Human Trypanosomiasis Pathogens. Pathogens 2022; 11:pathogens11090988. [PMID: 36145420 PMCID: PMC9505544 DOI: 10.3390/pathogens11090988] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 08/24/2022] [Accepted: 08/25/2022] [Indexed: 11/16/2022] Open
Abstract
Human trypanosomiasis affects nearly eight million people worldwide, causing great economic and social impact, mainly in endemic areas. T. cruzi and T. brucei are protozoan parasites that present efficient mechanisms of immune system evasion, leading to disease chronification. Currently, there is no vaccine, and chemotherapy is effective only in the absence of severe clinical manifestations. Nevertheless, resistant phenotypes to chemotherapy have been described in protozoan parasites, associated with cross-resistance to other chemically unrelated drugs. Multidrug resistance is multifactorial, involving: (i) drug entry, (ii) activation, (iii) metabolism and (iv) efflux pathways. In this context, ABC transporters, initially discovered in resistant tumor cells, have drawn attention in protozoan parasites, owing to their ability to decrease drug accumulation, thus mitigating their toxic effects. The discovery of these transporters in the Trypanosomatidae family started in the 1990s; however, few members were described and functionally characterized. This review contains a brief history of the main ABC transporters involved in resistance that propelled their investigation in Trypanosoma species, the main efflux modulators, as well as ABC genes described in T. cruzi and T. brucei according to the nomenclature HUGO. We hope to convey the importance that ABC transporters play in parasite physiology and chemotherapy resistance.
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Affiliation(s)
- Kelli Monteiro da Costa
- Laboratório de Glicobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
- Correspondence: (K.M.C.); (L.M.P.)
| | - Raphael do Carmo Valente
- Núcleo de Pesquisa Multidisciplinar em Biologia, Universidade Federal do Rio de Janeiro, Campus Duque de Caxias Prof. Geraldo Cidade, Duque de Caxias 25250-470, Brazil
| | - Leonardo Marques da Fonseca
- Laboratório de Glicobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - Leonardo Freire-de-Lima
- Laboratório de Glicobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - Jose Osvaldo Previato
- Laboratório de Glicobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - Lucia Mendonça-Previato
- Laboratório de Glicobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
- Correspondence: (K.M.C.); (L.M.P.)
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Huang PJ, Huang CY, Li YX, Liu YC, Chu LJ, Yeh YM, Cheng WH, Chen RM, Lee CC, Chen LC, Lin HC, Chiu SF, Lin WN, Lyu PC, Tang P, Huang KY. Dissecting the Transcriptomes of Multiple Metronidazole-Resistant and Sensitive Trichomonas vaginalis Strains Identified Distinct Genes and Pathways Associated with Drug Resistance and Cell Death. Biomedicines 2021; 9:biomedicines9121817. [PMID: 34944632 PMCID: PMC8698965 DOI: 10.3390/biomedicines9121817] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 11/25/2021] [Accepted: 11/30/2021] [Indexed: 12/20/2022] Open
Abstract
Trichomonas vaginalis is the causative agent of trichomoniasis, the most prevalent non-viral sexually transmitted infection worldwide. Metronidazole (MTZ) is the mainstay of anti-trichomonal chemotherapy; however, drug resistance has become an increasingly worrying issue. Additionally, the molecular events of MTZ-induced cell death in T. vaginalis remain elusive. To gain insight into the differential expression of genes related to MTZ resistance and cell death, we conducted RNA-sequencing of three paired MTZ-resistant (MTZ-R) and MTZ-sensitive (MTZ-S) T. vaginalis strains treated with or without MTZ. Comparative transcriptomes analysis identified that several putative drug-resistant genes were exclusively upregulated in different MTZ-R strains, such as ATP-binding cassette (ABC) transporters and multidrug resistance pumps. Additionally, several shared upregulated genes among all the MTZ-R transcriptomes were not previously identified in T. vaginalis, such as 5′-nucleotidase surE and Na+-driven multidrug efflux pump, which are a potential stress response protein and a multidrug and toxic compound extrusion (MATE)-like protein, respectively. Functional enrichment analysis revealed that purine and pyrimidine metabolisms were suppressed in MTZ-S parasites upon drug treatment, whereas the endoplasmic reticulum-associated degradation (ERAD) pathway, proteasome, and ubiquitin-mediated proteolysis were strikingly activated, highlighting the novel pathways responsible for drug-induced stress. Our work presents the most detailed analysis of the transcriptional changes and the regulatory networks associated with MTZ resistance and MTZ-induced signaling, providing insights into MTZ resistance and cell death mechanisms in trichomonads.
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Affiliation(s)
- Po-Jung Huang
- Department of Biomedical Sciences, Chang Gung University, Taoyuan City 333, Taiwan;
- Genomic Medicine Core Laboratory, Chang Gung Memorial Hospital, Linkou, Taoyuan City 333, Taiwan; (Y.-M.Y.); (C.-C.L.)
| | - Ching-Yun Huang
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei City 114, Taiwan; (C.-Y.H.); (S.-F.C.)
- Host-Parasite Interactions Laboratory, National Defense Medical Center, Taipei City 114, Taiwan
| | - Yu-Xuan Li
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan City 333, Taiwan; (Y.-X.L.); (L.-J.C.); (P.T.)
| | - Yi-Chung Liu
- Institute of Bioinformatics and Structural Biology, Department of Life Science, National Tsing Hua University, Hsinchu 300, Taiwan; (Y.-C.L.); (P.-C.L.)
| | - Lichieh-Julie Chu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan City 333, Taiwan; (Y.-X.L.); (L.-J.C.); (P.T.)
- Molecular Medicine Research Center, Chang Gung University, Taoyuan City 333, Taiwan
- Liver Research Center, Chang Gung Memorial Hospital, Linkou, Taoyuan City 333, Taiwan
| | - Yuan-Ming Yeh
- Genomic Medicine Core Laboratory, Chang Gung Memorial Hospital, Linkou, Taoyuan City 333, Taiwan; (Y.-M.Y.); (C.-C.L.)
| | - Wei-Hung Cheng
- Department of Medical Laboratory Science, College of Medicine, I-Shou University, Kaohsiung City 824, Taiwan;
| | - Ruei-Ming Chen
- Division of Clinical Pathology, Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei City 114, Taiwan; (R.-M.C.); (H.-C.L.)
| | - Chi-Ching Lee
- Genomic Medicine Core Laboratory, Chang Gung Memorial Hospital, Linkou, Taoyuan City 333, Taiwan; (Y.-M.Y.); (C.-C.L.)
- Department of Computer Science and Information Engineering, Chang Gung University, Taoyuan City 333, Taiwan
| | - Lih-Chyang Chen
- Department of Medicine, Mackay Medical College, New Taipei City 252, Taiwan;
| | - Hsin-Chung Lin
- Division of Clinical Pathology, Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei City 114, Taiwan; (R.-M.C.); (H.-C.L.)
- Graduate Institute of Pathology and Parasitology, National Defense Medical Center, Taipei City 114, Taiwan
| | - Shu-Fang Chiu
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei City 114, Taiwan; (C.-Y.H.); (S.-F.C.)
- Host-Parasite Interactions Laboratory, National Defense Medical Center, Taipei City 114, Taiwan
- Department of Inspection, Taipei City Hospital, Renai Branch, Taipei City 114, Taiwan
| | - Wei-Ning Lin
- Graduate Institute of Biomedical and Pharmaceutical Science, Fu Jen Catholic University, New Taipei City 242, Taiwan;
| | - Ping-Chiang Lyu
- Institute of Bioinformatics and Structural Biology, Department of Life Science, National Tsing Hua University, Hsinchu 300, Taiwan; (Y.-C.L.); (P.-C.L.)
| | - Petrus Tang
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan City 333, Taiwan; (Y.-X.L.); (L.-J.C.); (P.T.)
| | - Kuo-Yang Huang
- Host-Parasite Interactions Laboratory, National Defense Medical Center, Taipei City 114, Taiwan
- Graduate Institute of Pathology and Parasitology, National Defense Medical Center, Taipei City 114, Taiwan
- Correspondence: ; Tel.: +886-2-87923100 (ext. 18564)
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Steketee PC, Giordani F, Vincent IM, Crouch K, Achcar F, Dickens NJ, Morrison LJ, MacLeod A, Barrett MP. Transcriptional differentiation of Trypanosoma brucei during in vitro acquisition of resistance to acoziborole. PLoS Negl Trop Dis 2021; 15:e0009939. [PMID: 34752454 PMCID: PMC8648117 DOI: 10.1371/journal.pntd.0009939] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 12/06/2021] [Accepted: 10/21/2021] [Indexed: 11/19/2022] Open
Abstract
Subspecies of the protozoan parasite Trypanosoma brucei are the causative agents of Human African Trypanosomiasis (HAT), a debilitating neglected tropical disease prevalent across sub-Saharan Africa. HAT case numbers have steadily decreased since the start of the century, and sustainable elimination of one form of the disease is in sight. However, key to this is the development of novel drugs to combat the disease. Acoziborole is a recently developed benzoxaborole, currently in advanced clinical trials, for treatment of stage 1 and stage 2 HAT. Importantly, acoziborole is orally bioavailable, and curative with one dose. Recent studies have made significant progress in determining the molecular mode of action of acoziborole. However, less is known about the potential mechanisms leading to acoziborole resistance in trypanosomes. In this study, an in vitro-derived acoziborole-resistant cell line was generated and characterised. The AcoR line exhibited significant cross-resistance with the methyltransferase inhibitor sinefungin as well as hypersensitisation to known trypanocides. Interestingly, transcriptomics analysis of AcoR cells indicated the parasites had obtained a procyclic- or stumpy-like transcriptome profile, with upregulation of procyclin surface proteins as well as differential regulation of key metabolic genes known to be expressed in a life cycle-specific manner, even in the absence of major morphological changes. However, no changes were observed in transcripts encoding CPSF3, the recently identified protein target of acoziborole. The results suggest that generation of resistance to this novel compound in vitro can be accompanied by transcriptomic switches resembling a procyclic- or stumpy-type phenotype.
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Affiliation(s)
- Pieter C. Steketee
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, United Kingdom
| | - Federica Giordani
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| | - Isabel M. Vincent
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| | - Kathryn Crouch
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| | - Fiona Achcar
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| | - Nicholas J. Dickens
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| | - Liam J. Morrison
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, United Kingdom
| | - Annette MacLeod
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| | - Michael P. Barrett
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
- Glasgow Polyomics, University of Glasgow, United Kingdom
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Quintana JF, Field MC. Evolution, function and roles in drug sensitivity of trypanosome aquaglyceroporins. Parasitology 2021; 148:1137-1142. [PMID: 33602349 PMCID: PMC8311954 DOI: 10.1017/s0031182021000354] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/10/2021] [Accepted: 02/15/2021] [Indexed: 12/13/2022]
Abstract
Aquaglyceroporins (AQPs) are membrane proteins that function in osmoregulation and the uptake of low molecular weight solutes, in particular glycerol and urea. The AQP family is highly conserved, with two major subfamilies having arisen very early in prokaryote evolution and retained by eukaryotes. A complex evolutionary history indicates multiple lineage-specific expansions, losses and not uncommonly a complete loss. Consequently, the AQP family is highly evolvable and has been associated with significant events in life on Earth. In the African trypanosomes, a role for the AQP2 paralogue, in sensitivity to two chemotherapeutic agents, pentamidine and melarsoprol, is well established, albeit with the mechanisms for cell entry and resistance unclear until very recently. Here, we discuss AQP evolution, structure and mechanisms by which AQPs impact drug sensitivity, suggesting that AQP2 stability is highly sensitive to mutation while serving as the major uptake pathway for pentamidine.
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Affiliation(s)
- Juan F. Quintana
- Wellcome Centre for Integrative Parasitology (WCIP), Institute of Biodiversity, Animal Health and Comparative Medicine (IBAHCM), University of Glasgow, GlasgowG61 1QH, UK
| | - Mark C. Field
- School of Life Sciences, University of Dundee, DundeeDD1 5EH, UK
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 37005Ceske Budejovice, Czech Republic
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Abstract
Trypanothione is the primary thiol redox carrier in Trypanosomatids whose biosynthesis and utilization pathways contain unique enzymes that include suitable drug targets against the human parasites in this family. Overexpression of the rate-limiting enzyme, γ-glutamylcysteine synthetase (GSH1), can increase the intracellular concentration of trypanothione. Melarsoprol directly inhibits trypanothione and has predicted the effects on downstream redox biology, including ROS management and dNTP synthesis that require further investigation. Thus, we hypothesized that melarsoprol treatment would inhibit DNA synthesis, which was tested using BrdU incorporation assays and cell cycle analyses. In addition, we analysed the effects of eflornithine, which interfaces with the trypanothione pathway, fexinidazole, because of the predicted effects on DNA synthesis, and pentamidine as an experimental control. We found that melarsoprol treatment resulted in a cell cycle stall and a complete inhibition of DNA synthesis within 24 h, which were alleviated by GSH1 overexpression. In contrast, the other drugs analysed had more subtle effects on DNA synthesis that were not significantly altered by GSH1 expression. Together these findings implicate DNA synthesis as a therapeutic target that warrants further investigation in the development of antitrypanosomal drugs.
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A Trypanosoma brucei ORFeome-Based Gain-of-Function Library Identifies Genes That Promote Survival during Melarsoprol Treatment. mSphere 2020; 5:5/5/e00769-20. [PMID: 33028684 PMCID: PMC7568655 DOI: 10.1128/msphere.00769-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Trypanosoma brucei is an early branching protozoan parasite that causes human and animal African trypanosomiasis. Forward genetics approaches are powerful tools for uncovering novel aspects of trypanosomatid biology, pathogenesis, and therapeutic approaches against trypanosomiasis. Here, we have generated a T. brucei cloned ORFeome consisting of >90% of the targeted 7,245 genes and used it to make an inducible gain-of-function parasite library broadly applicable to large-scale forward genetic screens. We conducted a proof-of-principle genetic screen to identify genes whose expression promotes survival in melarsoprol, a critical drug of last resort. The 57 genes identified as overrepresented in melarsoprol survivor populations included the gene encoding the rate-limiting enzyme for the biosynthesis of an established drug target (trypanothione), validating the tool. In addition, novel genes associated with gene expression, flagellum localization, and mitochondrion localization were identified, and a subset of those genes increased melarsoprol resistance upon overexpression in culture. These findings offer new insights into trypanosomatid basic biology, implications for drug targets, and direct or indirect drug resistance mechanisms. This study generated a T. brucei ORFeome and gain-of-function parasite library, demonstrated the library's usefulness in forward genetic screening, and identified novel aspects of melarsoprol resistance that will be the subject of future investigations. These powerful genetic tools can be used to broadly advance trypanosomatid research.IMPORTANCE Trypanosomatid parasites threaten the health of more than 1 billion people worldwide. Because their genomes are highly diverged from those of well-established eukaryotes, conservation is not always useful in assigning gene functions. However, it is precisely among the trypanosomatid-specific genes that ideal therapeutic targets might be found. Forward genetics approaches are an effective way to identify novel gene functions. We used an ORFeome approach to clone a large percentage of Trypanosoma brucei genes and generate a gain-of-function parasite library. This library was used in a genetic screen to identify genes that promote resistance to the clinically significant yet highly toxic drug melarsoprol. Hits arising from the screen demonstrated the library's usefulness in identifying known pathways and uncovered novel aspects of resistance mediated by proteins localized to the flagellum and mitochondrion. The powerful new genetic tools generated herein are expected to promote advances in trypanosomatid biology and therapeutic development in the years to come.
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Nuryady MM, Widayanti R, Nurcahyo RW, Fadjrinatha B, Fahrurrozi Z S A. Characterization and phylogenetic analysis of multidrug-resistant protein - encoding genes in Trypanosoma evansi isolated from buffaloes in Ngawi district, Indonesia. Vet World 2019; 12:1573-1577. [PMID: 31849418 PMCID: PMC6868250 DOI: 10.14202/vetworld.2019.1573-1577] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 09/03/2019] [Indexed: 11/16/2022] Open
Abstract
Background and Aim: Excessive use of trypanocidal drugs can lead to cases of drug resistance. Multiple cases of resistance have been widely reported for drugs such as isometamidium chloride and diminazene aceturate. These cases deserve serious attention, especially in Indonesia, where the first case was recorded and where the molecular basis of trypanocidal drug resistance has never been evaluated. This study aimed to analyze the multidrug resistance protein (MRP) gene in Trypanosoma evansi isolates, sampled from Indonesia, by focusing on the phylogenetic relationship between these isolates and other Trypanosoma spp. Materials and Methods: A total of 88 blood samples were drawn from buffaloes in the Ngawi district, Indonesia. Animals infected with T. evansi were detected through the microhematocrit technique and Giemsa blood smear methods. Positive blood samples were used to inoculate in male mice (Mus musculus BALB-C strain) as an animal model for culturing the T. evansi. The genomic DNA of the blood taken from the T. evansi- infected mice was used for polymerase chain reaction amplification, sequencing, and phylogenetic analysis. Results: Two genes were analyzed; the first gene detected for T. evansi corresponded to Trypanosomabrucei with a homology of 99% and the second gene to Trypanosoma brucei gambiense, with a homology of 100%. These two genes of the MRP from T. evansi showed clear similarity to the MRPE and MRPA genes of the T. brucei ssp. Conclusion: The MRP gene is conserved on the subspecies level of T. brucei. Only few point mutations were found between various sequences, which mean that the proteins have the same structure. This is important to treat the parasite with the appropriate drugs in the future.
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Affiliation(s)
- Mohammad Mirza Nuryady
- Department of Biology Education, Faculty of Teacher Training and Education, Universitas Muhammadiyah Malang, Malang, Indonesia
| | - Rini Widayanti
- Department of Biochemistry, Veterinary Medicine Faculty, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Raden Wisnu Nurcahyo
- Department of Parasitology, Veterinary Medicine Faculty, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Brilyantika Fadjrinatha
- Department of Parasitology, Veterinary Medicine Faculty, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Ahmad Fahrurrozi Z S
- Department of Tropical Medicine, Medicine Faculty, Universitas Gadjah Mada, Yogyakarta, Indonesia
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Patino LH, Muskus C, Ramírez JD. Transcriptional responses of Leishmania (Leishmania) amazonensis in the presence of trivalent sodium stibogluconate. Parasit Vectors 2019; 12:348. [PMID: 31300064 PMCID: PMC6626383 DOI: 10.1186/s13071-019-3603-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 07/06/2019] [Indexed: 12/13/2022] Open
Abstract
Background In the last decade, resistance to antimonials has become a serious problem due to the emergence of drug-resistant strains. Therefore, understanding the mechanisms used by Leishmania parasites to survive under drug pressure is essential, particularly for species of medical-veterinary importance such as L. amazonensis. Methods Here, we used RNA-seq technology to analyse transcriptome profiles and identify global changes in gene expression between antimony-resistant and -sensitive L. amazonensis promastigotes. Results A total of 723 differentially expressed genes were identified between resistant and sensitive lines. Comparative transcriptomic analysis revealed that genes encoding proteins involved in metabolism (fatty acids) and stress response, as well as those associated with antimony resistance in other Leishmania species, were upregulated in the antimony-resistant line. Most importantly, we observed upregulation of genes encoding autophagy proteins, suggesting that in the presence of trivalent stibogluconate (SbIII) L. amazonensis can activate these genes either as a survival strategy or to induce cell death, as has been observed in other parasites. Conclusions This work identified global transcriptomic changes in an in vitro-adapted strain in response to SbIII. Our results provide relevant information to continue understanding the mechanism used by parasites of the subgenus Leishmania (L. amazonensis) to generate an antimony-resistant phenotype. Electronic supplementary material The online version of this article (10.1186/s13071-019-3603-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Luz H Patino
- Grupo de Investigaciones Microbiológicas-UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
| | - Carlos Muskus
- Programa de Estudio y Control de Enfermedades Tropicales (PECET), Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia
| | - Juan David Ramírez
- Grupo de Investigaciones Microbiológicas-UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia.
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11
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Pramanik PK, Alam MN, Roy Chowdhury D, Chakraborti T. Drug Resistance in Protozoan Parasites: An Incessant Wrestle for Survival. J Glob Antimicrob Resist 2019; 18:1-11. [PMID: 30685461 DOI: 10.1016/j.jgar.2019.01.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 01/04/2019] [Accepted: 01/15/2019] [Indexed: 11/19/2022] Open
Abstract
Nowadays, drug resistance in parasites is considered to be one of the foremost concerns in health and disease management. It is interconnected worldwide and undermines the health of millions of people, threatening to grow worse. Unfortunately, it does not receive serious attention from every corner of society. Consequently, drug resistance in parasites is gradually complicating and challenging the treatment of parasitic diseases. In this context, we have dedicated ourselves to review the incidence of drug resistance in the protozoan parasites Plasmodium, Leishmania, Trypanosoma, Entamoeba and Toxoplasma gondii. Moreover, understanding the role of ATP-binding cassette (ABC) transporters in drug resistance is essential in the control of parasitic diseases. Therefore, we also focused on the involvement of ABC transporters in drug resistance, which will be a superior approach to find ways for better regulation of diseases caused by parasitic infections.
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Affiliation(s)
- Pijush Kanti Pramanik
- Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741235, West Bengal, India
| | - Md Nur Alam
- Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741235, West Bengal, India
| | - Dibyapriya Roy Chowdhury
- Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741235, West Bengal, India
| | - Tapati Chakraborti
- Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741235, West Bengal, India.
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da Costa KM, Valente RC, Salustiano EJ, Gentile LB, Freire-de-Lima L, Mendonça-Previato L, Previato JO. Functional Characterization of ABCC Proteins from Trypanosoma cruzi and Their Involvement with Thiol Transport. Front Microbiol 2018; 9:205. [PMID: 29491856 PMCID: PMC5817095 DOI: 10.3389/fmicb.2018.00205] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 01/29/2018] [Indexed: 11/13/2022] Open
Abstract
Chagas disease is a neglected disease caused by the protozoan Trypanosoma cruzi and affects 8 million people worldwide. The main chemotherapy is based on benznidazole. The efficacy in the treatment depends on factors such as the parasite strain, which may present different sensitivity to treatment. In this context, the expression of ABC transporters has been related to chemotherapy failure. ABC transporters share a well-conserved ABC domain, responsible for ATP binding and hydrolysis, whose the energy released is coupled to transport of molecules through membranes. The most known ABC transporters are ABCB1 and ABCC1, involved in the multidrug resistance phenotype in cancer, given their participation in cellular detoxification. In T. cruzi, 27 ABC genes were identified in the genome. Nonetheless, only four ABC genes were characterized: ABCA3, involved in vesicular trafficking; ABCG1, overexpressed in strains naturally resistant to benznidazole, and P-glycoprotein 1 and 2, whose participation in drug resistance is controversial. Considering P-glycoprotein genes are related to ABCC subfamily in T. cruzi according to the demonstration using BLASTP alignment, we evaluated both ABCB1-like and ABCC-like activities in epimastigote and trypomastigote forms of the Y strain. The transport activities were evaluated by the efflux of the fluorescent dyes Rhodamine 123 and Carboxyfluorescein in a flow cytometer. Results indicated that there was no ABCB1-like activity in both T. cruzi forms. Conversely, results demonstrated ABCC-like activity in both epimastigote and trypomastigote forms of T. cruzi. This activity was inhibited by ABCC transport modulators (probenecid, indomethacin, and MK-571), by ATP-depleting agents (sodium azide and iodoacetic acid) and by the thiol-depleting agent N-ethylmaleimide. Additionally, the presence of ABCC-like activity was supported by direct inhibition of the thiol-conjugated compound efflux with indomethacin, characteristic of ABCC subfamily members. Taken together, the results provide the first description of native ABCC-like activity in T. cruzi epimastigote and trypomastigote forms, indicating that the study of the biological role for that thiol transporter is crucial to reveal new molecular mechanisms for therapeutic approaches in the Chagas disease.
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Affiliation(s)
- Kelli Monteiro da Costa
- Laboratório de Glicobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Raphael C Valente
- Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Eduardo J Salustiano
- Laboratório de Glicobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luciana B Gentile
- Laboratório de Glicobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Leonardo Freire-de-Lima
- Laboratório de Glicobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lucia Mendonça-Previato
- Laboratório de Glicobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - José O Previato
- Laboratório de Glicobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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Franco J, Scarone L, Comini MA. Drugs and Drug Resistance in African and American Trypanosomiasis. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2018. [DOI: 10.1016/bs.armc.2018.08.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Genomic analysis of Isometamidium Chloride resistance in Trypanosoma congolense. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2017; 7:350-361. [PMID: 29032180 PMCID: PMC5645165 DOI: 10.1016/j.ijpddr.2017.10.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 10/02/2017] [Accepted: 10/05/2017] [Indexed: 12/30/2022]
Abstract
Isometamidium Chloride (ISM) is one of the principal drugs used to counteract Trypanosoma congolense infection in livestock, both as a prophylactic as well as a curative treatment. However, numerous cases of ISM resistance have been reported in different African regions, representing a significant constraint in the battle against Animal African Trypanosomiasis. In order to identify genetic signatures associated with ISM resistance in T. congolense, the sensitive strain MSOROM7 was selected for induction of ISM resistance in a murine host. Administered ISM concentrations in immune-suppressed mice were gradually increased from 0.001 mg/kg to 1 mg/kg, the maximal dose used in livestock. As a result, three independent MSOROM7 lines acquired full resistance to this concentration after five months of induction, and retained this full resistant phenotype following a six months period without drug pressure. In contrast, parasites did not acquire ISM resistance in immune-competent animals, even after more than two years under ISM pressure, suggesting that the development of full ISM resistance is strongly enhanced when the host immune response is compromised. Genomic analyses comparing the ISM resistant lines with the parental sensitive line identified shifts in read depth at heterozygous loci in genes coding for different transporters and transmembrane products, and several of these shifts were also found within natural ISM resistant isolates. These findings suggested that the transport and accumulation of ISM inside the resistant parasites may be modified, which was confirmed by flow cytometry and ex vivo ISM uptake assays that showed a decrease in the accumulation of ISM in the resistant parasites.
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Ulrich K, Finkenzeller C, Merker S, Rojas F, Matthews K, Ruppert T, Krauth-Siegel RL. Stress-Induced Protein S-Glutathionylation and S-Trypanothionylation in African Trypanosomes-A Quantitative Redox Proteome and Thiol Analysis. Antioxid Redox Signal 2017; 27:517-533. [PMID: 28338335 PMCID: PMC5567454 DOI: 10.1089/ars.2016.6947] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
AIMS Trypanosomatids have a unique trypanothione-based thiol redox metabolism. The parasite-specific dithiol is synthesized from glutathione and spermidine, with glutathionylspermidine as intermediate catalyzed by trypanothione synthetase. In this study, we address the oxidative stress response of African trypanosomes with special focus on putative protein S-thiolation. RESULTS Challenging bloodstream Trypanosoma brucei with diamide, H2O2 or hypochlorite results in distinct levels of reversible overall protein S-thiolation. Quantitative proteome analyses reveal 84 proteins oxidized in diamide-stressed parasites. Fourteen of them, including several essential thiol redox proteins and chaperones, are also enriched when glutathione/glutaredoxin serves as a reducing system indicating S-thiolation. In parasites exposed to H2O2, other sets of proteins are modified. Only three proteins are S-thiolated under all stress conditions studied in accordance with a highly specific response. H2O2 causes primarily the formation of free disulfides. In contrast, in diamide-treated cells, glutathione, glutathionylspermidine, and trypanothione are almost completely protein bound. Remarkably, the total level of trypanothione is decreased, whereas those of glutathione and glutathionylspermidine are increased, indicating partial hydrolysis of protein-bound trypanothione. Depletion of trypanothione synthetase exclusively induces protein S-glutathionylation. Total mass analyses of a recombinant peroxidase treated with T(SH)2 and either diamide or hydrogen peroxide verify protein S-trypanothionylation as stable modification. INNOVATION Our data reveal for the first time that trypanosomes employ protein S-thiolation when exposed to exogenous and endogenous oxidative stresses and trypanothione, despite its dithiol character, forms protein-mixed disulfides. CONCLUSION The stress-specific responses shown here emphasize protein S-trypanothionylation and S-glutathionylation as reversible protection mechanism in these parasites. Antioxid. Redox Signal. 27, 517-533.
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Affiliation(s)
- Kathrin Ulrich
- 1 Biochemie-Zentrum der Universität Heidelberg (BZH) , Heidelberg, Germany
| | | | - Sabine Merker
- 2 Zentrum für Molekularbiologie der Universität Heidelberg (ZMBH) , Heidelberg, Germany
| | - Federico Rojas
- 3 Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh , Edinburgh, United Kingdom
| | - Keith Matthews
- 3 Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh , Edinburgh, United Kingdom
| | - Thomas Ruppert
- 2 Zentrum für Molekularbiologie der Universität Heidelberg (ZMBH) , Heidelberg, Germany
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16
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Daunes S, Yardley V, Croft SL, D'Silva C. Antiprotozoal glutathione derivatives with flagellar membrane binding activity against T. brucei rhodesiense. Bioorg Med Chem 2016; 25:1329-1340. [PMID: 28131508 DOI: 10.1016/j.bmc.2016.12.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Revised: 12/05/2016] [Accepted: 12/10/2016] [Indexed: 12/16/2022]
Abstract
A new series of N-substituted S-(2,4-dinitrophenyl)glutathione dibutyl diesters were synthesized to improve in vitro anti-protozoal activity against the pathogenic parasites Trypanosoma brucei rhodesiense, Trypanosoma cruzi and Leishmania donovani. The results obtained indicate that N-substituents enhance the inhibitory properties of glutathione diesters whilst showing reduced toxicity against KB cells as in the cases of compounds 5, 9, 10, 16, 18 and 19. We suggest that the interaction of N-substituted S-(2,4-dinitrophenyl) glutathione dibutyl diesters with T. b. brucei occurs mainly by weak hydrophobic interactions such as London and van der Waals forces. A QSAR study indicated that the inhibitory activity of the peptide is associated negatively with the average number of C atoms, NC and positively to SZX, the ZX shadow a geometric descriptor related to molecular size and orientation of the compound. HPLC-UV studies in conjunction with optical microscopy indicate that the observed selectivity of inhibition of these compounds against bloodstream form T. b. brucei parasites in comparison to L. donovani under the same conditions is due to intracellular uptake via endocytosis in the flagellar pocket.
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Affiliation(s)
- Sylvie Daunes
- School of Chemistry and Environmental Sciences, The Manchester Metropolitan University, Faculty of Science and Engineering, John Dalton Building, Chester Street, Manchester M1 5GD, UK
| | - Vanessa Yardley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Simon L Croft
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Claudius D'Silva
- School of Chemistry and Environmental Sciences, The Manchester Metropolitan University, Faculty of Science and Engineering, John Dalton Building, Chester Street, Manchester M1 5GD, UK; School of Chemistry, Central University of Rajasthan, Bandar Sindari, Jaipur-Ajmer Highway (Rajasthan), India.
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17
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Rahbari M, Diederich K, Becker K, Krauth-Siegel RL, Jortzik E. Detection of thiol-based redox switch processes in parasites - facts and future. Biol Chem 2016; 396:445-63. [PMID: 25741735 DOI: 10.1515/hsz-2014-0279] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 02/23/2015] [Indexed: 12/28/2022]
Abstract
Malaria and African trypanosomiasis are tropical diseases caused by the protozoa Plasmodium and Trypanosoma, respectively. The parasites undergo complex life cycles in the mammalian host and insect vector, during which they are exposed to oxidative and nitrosative challenges induced by the host immune system and endogenous processes. Attacking the parasite's redox metabolism is a target mechanism of several known antiparasitic drugs and a promising approach to novel drug development. Apart from this aspect, oxidation of cysteine residues plays a key role in protein-protein interaction, metabolic responses to redox events, and signaling. Understanding the role and dynamics of reactive oxygen species and thiol switches in regulating cellular redox homeostasis is crucial for both basic and applied biomedical approaches. Numerous techniques have therefore been established to detect redox changes in parasites including biochemical methods, fluorescent dyes, and genetically encoded probes. In this review, we aim to give an insight into the characteristics of redox networks in the pathogens Plasmodium and Trypanosoma, including a comprehensive overview of the consequences of specific deletions of redox-associated genes. Furthermore, we summarize mechanisms and detection methods of thiol switches in both parasites and discuss their specificity and sensitivity.
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18
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Richardson JB, Evans B, Pyana PP, Van Reet N, Sistrom M, Büscher P, Aksoy S, Caccone A. Whole genome sequencing shows sleeping sickness relapse is due to parasite regrowth and not reinfection. Evol Appl 2016; 9:381-93. [PMID: 26834831 PMCID: PMC4721075 DOI: 10.1111/eva.12338] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Accepted: 09/29/2015] [Indexed: 11/27/2022] Open
Abstract
The trypanosome Trypanosoma brucei gambiense (Tbg) is a cause of human African trypanosomiasis (HAT) endemic to many parts of sub-Saharan Africa. The disease is almost invariably fatal if untreated and there is no vaccine, which makes monitoring and managing drug resistance highly relevant. A recent study of HAT cases from the Democratic Republic of the Congo reported a high incidence of relapses in patients treated with melarsoprol. Of the 19 Tbg strains isolated from patients enrolled in this study, four pairs were obtained from the same patient before treatment and after relapse. We used whole genome sequencing to investigate whether these patients were infected with a new strain, or if the original strain had regrown to pathogenic levels. Clustering analysis of 5938 single nucleotide polymorphisms supports the hypothesis of regrowth of the original strain, as we found that strains isolated before and after treatment from the same patient were more similar to each other than to other isolates. We also identified 23 novel genes that could affect melarsoprol sensitivity, representing a promising new set of targets for future functional studies. This work exemplifies the utility of using evolutionary approaches to provide novel insights and tools for disease control.
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Affiliation(s)
- Joshua B Richardson
- Department of Ecology and Evolutionary Biology Yale University New Haven CT USA
| | - Benjamin Evans
- Department of Ecology and Evolutionary Biology Yale University New Haven CT USA
| | - Patient P Pyana
- Department de Parasitologie Institut National de Recherche Biomedicale Kinshasa Gombe Democratic Republic of the Congo
| | - Nick Van Reet
- Department of Biomedical Sciences Institute of Tropical Medicine Antwerp Belgium
| | - Mark Sistrom
- School of Natural Sciences University of California Merced Merced CA USA
| | - Philippe Büscher
- Department of Biomedical Sciences Institute of Tropical Medicine Antwerp Belgium
| | - Serap Aksoy
- Department of Epidemiology and Public Health Yale School of Public Health New Haven CT USA
| | - Adalgisa Caccone
- Department of Ecology and Evolutionary Biology Yale University New Haven CT USA
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Foscolos AS, Papanastasiou I, Foscolos GB, Tsotinis A, Kellici TF, Mavromoustakos T, Taylor MC, Kelly JM. New hydrazones of 5-nitro-2-furaldehyde with adamantanealkanohydrazides: synthesis and in vitro trypanocidal activity. MEDCHEMCOMM 2016. [DOI: 10.1039/c6md00035e] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A range of hydrazones of 5-nitro-2-furaldehyde with adamantane alkanohydrazides was synthesized and their trypanocidal activity was evaluated.
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Affiliation(s)
- Angeliki-Sofia Foscolos
- School of Health Sciences
- Faculty of Pharmacy
- Department of Pharmaceutical Chemistry
- National and Kapodistrian University of Athens
- 15784 Athens
| | - Ioannis Papanastasiou
- School of Health Sciences
- Faculty of Pharmacy
- Department of Pharmaceutical Chemistry
- National and Kapodistrian University of Athens
- 15784 Athens
| | - George B. Foscolos
- School of Health Sciences
- Faculty of Pharmacy
- Department of Pharmaceutical Chemistry
- National and Kapodistrian University of Athens
- 15784 Athens
| | - Andrew Tsotinis
- School of Health Sciences
- Faculty of Pharmacy
- Department of Pharmaceutical Chemistry
- National and Kapodistrian University of Athens
- 15784 Athens
| | - Tahsin F. Kellici
- Faculty of Chemistry
- Department of Organic Chemistry
- University of Athens
- 15771 Athens
- Greece
| | - Thomas Mavromoustakos
- Faculty of Chemistry
- Department of Organic Chemistry
- University of Athens
- 15771 Athens
- Greece
| | - Martin C. Taylor
- Department of Pathogen Molecular Biology
- London School of Hygiene and Tropical Medicine
- London WC1 E7HT
- UK
| | - John M. Kelly
- Department of Pathogen Molecular Biology
- London School of Hygiene and Tropical Medicine
- London WC1 E7HT
- UK
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20
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The emergence of macrocyclic lactone resistance in the canine heartworm, Dirofilaria immitis. Parasitology 2015; 142:1249-59. [PMID: 26040450 DOI: 10.1017/s003118201500061x] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Prevention of heartworm disease caused by Dirofilaria immitis in domestic dogs and cats relies on a single drug class, the macrocyclic lactones (MLs). Recently, it has been demonstrated that ML-resistant D. immitis are circulating in the Mississippi Delta region of the USA, but the prevalence and impact of these resistant parasites remains unknown. We review published studies that demonstrated resistance in D.immitis, along with our current understanding of its mechanisms. Efforts to develop in vitro tests for resistance have not yet yielded a suitable assay, so testing infected animals for microfilariae that persist in the face of ML treatment may be the best current option. Since the vast majority of D. immitis populations continue to be drug-sensitive, protected dogs are likely to be infected with only a few parasites and experience relatively mild disease. In cats, infection with small numbers of worms can cause severe disease and so the clinical consequences of drug resistance may be more severe. Since melarsomine dihydrochloride, the drug used to remove adult worms, is not an ML, the ML-resistance should have no impact on our ability to treat diseased animals. A large refugium of heartworms that are not exposed to drugs exists in unprotected dogs and in wild canids, which may limit the development and spread of resistance alleles.
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Shimogawa MM, Saada EA, Vashisht AA, Barshop WD, Wohlschlegel JA, Hill KL. Cell Surface Proteomics Provides Insight into Stage-Specific Remodeling of the Host-Parasite Interface in Trypanosoma brucei. Mol Cell Proteomics 2015; 14:1977-88. [PMID: 25963835 DOI: 10.1074/mcp.m114.045146] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Indexed: 02/05/2023] Open
Abstract
African trypanosomes are devastating human and animal pathogens transmitted by tsetse flies between mammalian hosts. The trypanosome surface forms a critical host interface that is essential for sensing and adapting to diverse host environments. However, trypanosome surface protein composition and diversity remain largely unknown. Here, we use surface labeling, affinity purification, and proteomic analyses to describe cell surface proteomes from insect-stage and mammalian bloodstream-stage Trypanosoma brucei. The cell surface proteomes contain most previously characterized surface proteins. We additionally identify a substantial number of novel proteins, whose functions are unknown, indicating the parasite surface proteome is larger and more diverse than generally appreciated. We also show stage-specific expression for individual paralogs within several protein families, suggesting that fine-tuned remodeling of the parasite surface allows adaptation to diverse host environments, while still fulfilling universally essential cellular needs. Our surface proteome analyses complement existing transcriptomic, proteomic, and in silico analyses by highlighting proteins that are surface-exposed and thereby provide a major step forward in defining the host-parasite interface.
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Affiliation(s)
- Michelle M Shimogawa
- From the ‡Department of Microbiology, Immunology, and Molecular Genetics, University of California Los Angeles, Los Angeles, California, 90095
| | - Edwin A Saada
- From the ‡Department of Microbiology, Immunology, and Molecular Genetics, University of California Los Angeles, Los Angeles, California, 90095
| | - Ajay A Vashisht
- §Department of Biological Chemistry, University of California Los Angeles, Los Angeles, California 90095
| | - William D Barshop
- §Department of Biological Chemistry, University of California Los Angeles, Los Angeles, California 90095
| | - James A Wohlschlegel
- §Department of Biological Chemistry, University of California Los Angeles, Los Angeles, California 90095; ¶Molecular Biology Institute, University of California Los Angeles, Los Angeles, California 90095
| | - Kent L Hill
- From the ‡Department of Microbiology, Immunology, and Molecular Genetics, University of California Los Angeles, Los Angeles, California, 90095; ¶Molecular Biology Institute, University of California Los Angeles, Los Angeles, California 90095
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22
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Alkhaldi AAM, Creek DJ, Ibrahim H, Kim DH, Quashie NB, Burgess KE, Changtam C, Barrett MP, Suksamrarn A, de Koning HP. Potent trypanocidal curcumin analogs bearing a monoenone linker motif act on trypanosoma brucei by forming an adduct with trypanothione. Mol Pharmacol 2014; 87:451-64. [PMID: 25527638 DOI: 10.1124/mol.114.096016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We have previously reported that curcumin analogs with a C7 linker bearing a C4-C5 olefinic linker with a single keto group at C3 (enone linker) display midnanomolar activity against the bloodstream form of Trypanosoma brucei. However, no clear indication of their mechanism of action or superior antiparasitic activity relative to analogs with the original di-ketone curcumin linker was apparent. To further investigate their utility as antiparasitic agents, we compare the cellular effects of curcumin and the enone linker lead compound 1,7-bis(4-hydroxy-3-methoxyphenyl)hept-4-en-3-one (AS-HK014) here. An AS-HK014-resitant line, trypanosomes adapted to AS-HK014 (TA014), was developed by in vitro exposure to the drug. Metabolomic analysis revealed that exposure to AS-HK014, but not curcumin, rapidly depleted glutathione and trypanothione in the wild-type line, although almost all other metabolites were unchanged relative to control. In TA014 cells, thiol levels were similar to untreated wild-type cells and not significantly depleted by AS-HK014. Adducts of AS-HK014 with both glutathione and trypanothione were identified in AS-HK014-exposed wild-type cells and reproduced by chemical reaction. However, adduct accumulation in sensitive cells was much lower than in resistant cells. TA014 cells did not exhibit any changes in sequence or protein levels of glutathione synthetase and γ-glutamylcysteine synthetase relative to wild-type cells. We conclude that monoenone curcuminoids have a different mode of action than curcumin, rapidly and specifically depleting thiol levels in trypanosomes by forming an adduct. This adduct may ultimately be responsible for the highly potent trypanocidal and antiparasitic activity of the monoenone curcuminoids.
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Affiliation(s)
- Abdulsalam A M Alkhaldi
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (A.A.M.A, D.J.C., H.I., D.-H.K., N.B.Q., K.E.B., M.P.B., H.P.K.); Department of Biology, College of Science, Aljouf University, Skaka, Kingdom of Saudi Arabia (A.A.M.A); Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Australia (D.J.C.); Faculty of Science, Department of Zoology, Sebha University, Libya (H.I.); Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom (D.-H.K.); Centre for Tropical Clinical Pharmacology and Therapeutics, University of Ghana Medical School, Accra, Ghana (N.B.Q.); Division of Physical Science, Faculty of Science and Technology, Huachiew Chalermprakiet University, Samutprakarn, Thailand (C.C.); Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, United Kingdom (M.P.B.); and Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ramkhamhaeng University, Bangkok, Thailand (A.S.)
| | - Darren J Creek
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (A.A.M.A, D.J.C., H.I., D.-H.K., N.B.Q., K.E.B., M.P.B., H.P.K.); Department of Biology, College of Science, Aljouf University, Skaka, Kingdom of Saudi Arabia (A.A.M.A); Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Australia (D.J.C.); Faculty of Science, Department of Zoology, Sebha University, Libya (H.I.); Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom (D.-H.K.); Centre for Tropical Clinical Pharmacology and Therapeutics, University of Ghana Medical School, Accra, Ghana (N.B.Q.); Division of Physical Science, Faculty of Science and Technology, Huachiew Chalermprakiet University, Samutprakarn, Thailand (C.C.); Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, United Kingdom (M.P.B.); and Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ramkhamhaeng University, Bangkok, Thailand (A.S.)
| | - Hasan Ibrahim
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (A.A.M.A, D.J.C., H.I., D.-H.K., N.B.Q., K.E.B., M.P.B., H.P.K.); Department of Biology, College of Science, Aljouf University, Skaka, Kingdom of Saudi Arabia (A.A.M.A); Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Australia (D.J.C.); Faculty of Science, Department of Zoology, Sebha University, Libya (H.I.); Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom (D.-H.K.); Centre for Tropical Clinical Pharmacology and Therapeutics, University of Ghana Medical School, Accra, Ghana (N.B.Q.); Division of Physical Science, Faculty of Science and Technology, Huachiew Chalermprakiet University, Samutprakarn, Thailand (C.C.); Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, United Kingdom (M.P.B.); and Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ramkhamhaeng University, Bangkok, Thailand (A.S.)
| | - Dong-Hyun Kim
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (A.A.M.A, D.J.C., H.I., D.-H.K., N.B.Q., K.E.B., M.P.B., H.P.K.); Department of Biology, College of Science, Aljouf University, Skaka, Kingdom of Saudi Arabia (A.A.M.A); Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Australia (D.J.C.); Faculty of Science, Department of Zoology, Sebha University, Libya (H.I.); Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom (D.-H.K.); Centre for Tropical Clinical Pharmacology and Therapeutics, University of Ghana Medical School, Accra, Ghana (N.B.Q.); Division of Physical Science, Faculty of Science and Technology, Huachiew Chalermprakiet University, Samutprakarn, Thailand (C.C.); Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, United Kingdom (M.P.B.); and Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ramkhamhaeng University, Bangkok, Thailand (A.S.)
| | - Neils B Quashie
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (A.A.M.A, D.J.C., H.I., D.-H.K., N.B.Q., K.E.B., M.P.B., H.P.K.); Department of Biology, College of Science, Aljouf University, Skaka, Kingdom of Saudi Arabia (A.A.M.A); Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Australia (D.J.C.); Faculty of Science, Department of Zoology, Sebha University, Libya (H.I.); Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom (D.-H.K.); Centre for Tropical Clinical Pharmacology and Therapeutics, University of Ghana Medical School, Accra, Ghana (N.B.Q.); Division of Physical Science, Faculty of Science and Technology, Huachiew Chalermprakiet University, Samutprakarn, Thailand (C.C.); Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, United Kingdom (M.P.B.); and Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ramkhamhaeng University, Bangkok, Thailand (A.S.)
| | - Karl E Burgess
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (A.A.M.A, D.J.C., H.I., D.-H.K., N.B.Q., K.E.B., M.P.B., H.P.K.); Department of Biology, College of Science, Aljouf University, Skaka, Kingdom of Saudi Arabia (A.A.M.A); Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Australia (D.J.C.); Faculty of Science, Department of Zoology, Sebha University, Libya (H.I.); Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom (D.-H.K.); Centre for Tropical Clinical Pharmacology and Therapeutics, University of Ghana Medical School, Accra, Ghana (N.B.Q.); Division of Physical Science, Faculty of Science and Technology, Huachiew Chalermprakiet University, Samutprakarn, Thailand (C.C.); Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, United Kingdom (M.P.B.); and Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ramkhamhaeng University, Bangkok, Thailand (A.S.)
| | - Chatchawan Changtam
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (A.A.M.A, D.J.C., H.I., D.-H.K., N.B.Q., K.E.B., M.P.B., H.P.K.); Department of Biology, College of Science, Aljouf University, Skaka, Kingdom of Saudi Arabia (A.A.M.A); Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Australia (D.J.C.); Faculty of Science, Department of Zoology, Sebha University, Libya (H.I.); Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom (D.-H.K.); Centre for Tropical Clinical Pharmacology and Therapeutics, University of Ghana Medical School, Accra, Ghana (N.B.Q.); Division of Physical Science, Faculty of Science and Technology, Huachiew Chalermprakiet University, Samutprakarn, Thailand (C.C.); Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, United Kingdom (M.P.B.); and Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ramkhamhaeng University, Bangkok, Thailand (A.S.)
| | - Michael P Barrett
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (A.A.M.A, D.J.C., H.I., D.-H.K., N.B.Q., K.E.B., M.P.B., H.P.K.); Department of Biology, College of Science, Aljouf University, Skaka, Kingdom of Saudi Arabia (A.A.M.A); Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Australia (D.J.C.); Faculty of Science, Department of Zoology, Sebha University, Libya (H.I.); Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom (D.-H.K.); Centre for Tropical Clinical Pharmacology and Therapeutics, University of Ghana Medical School, Accra, Ghana (N.B.Q.); Division of Physical Science, Faculty of Science and Technology, Huachiew Chalermprakiet University, Samutprakarn, Thailand (C.C.); Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, United Kingdom (M.P.B.); and Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ramkhamhaeng University, Bangkok, Thailand (A.S.)
| | - Apichart Suksamrarn
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (A.A.M.A, D.J.C., H.I., D.-H.K., N.B.Q., K.E.B., M.P.B., H.P.K.); Department of Biology, College of Science, Aljouf University, Skaka, Kingdom of Saudi Arabia (A.A.M.A); Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Australia (D.J.C.); Faculty of Science, Department of Zoology, Sebha University, Libya (H.I.); Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom (D.-H.K.); Centre for Tropical Clinical Pharmacology and Therapeutics, University of Ghana Medical School, Accra, Ghana (N.B.Q.); Division of Physical Science, Faculty of Science and Technology, Huachiew Chalermprakiet University, Samutprakarn, Thailand (C.C.); Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, United Kingdom (M.P.B.); and Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ramkhamhaeng University, Bangkok, Thailand (A.S.)
| | - Harry P de Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom (A.A.M.A, D.J.C., H.I., D.-H.K., N.B.Q., K.E.B., M.P.B., H.P.K.); Department of Biology, College of Science, Aljouf University, Skaka, Kingdom of Saudi Arabia (A.A.M.A); Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Australia (D.J.C.); Faculty of Science, Department of Zoology, Sebha University, Libya (H.I.); Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom (D.-H.K.); Centre for Tropical Clinical Pharmacology and Therapeutics, University of Ghana Medical School, Accra, Ghana (N.B.Q.); Division of Physical Science, Faculty of Science and Technology, Huachiew Chalermprakiet University, Samutprakarn, Thailand (C.C.); Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, United Kingdom (M.P.B.); and Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ramkhamhaeng University, Bangkok, Thailand (A.S.)
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Drug discovery and human African trypanosomiasis: a disease less neglected? Future Med Chem 2014; 5:1801-41. [PMID: 24144414 DOI: 10.4155/fmc.13.162] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Human African trypanosomiasis (HAT) has been neglected for a long time. The most recent drug to treat this disease, eflornithine, was approved by the US FDA in 2000. Current treatments exhibit numerous problematic side effects and are often ineffective against the debilitating CNS resident stage of the disease. Fortunately, several partnerships and initiatives have been formed over the last 20 years in an effort to eradicate HAT, along with a number of other neglected diseases. This has led to an increasing number of foundations and research institutions that are currently working on the development of new drugs for HAT and tools with which to diagnose and treat patients. New biochemical pathways as therapeutic targets are emerging, accompanied by increasing numbers of new antitrypanosomal compound classes. The future looks promising that this collaborative approach will facilitate eagerly awaited breakthroughs in the treatment of HAT.
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24
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Genetic validation of Trypanosoma brucei glutathione synthetase as an essential enzyme. EUKARYOTIC CELL 2014; 13:614-24. [PMID: 24610661 DOI: 10.1128/ec.00015-14] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Human African trypanosomiasis (HAT) is a debilitating and fatal vector-borne disease. Polyamine biosynthesis is the target of one of the key drugs (eflornithine) used for the treatment of late-stage disease, suggesting that the pathway might be exploited for the identification of additional drug targets. The polyamine spermidine is required in trypanosomatid parasites for formation of a unique redox cofactor termed trypanothione, which is formed from the conjugation of glutathione to spermidine. Here we characterize recombinant Trypanosoma brucei glutathione synthetase (TbGS) and show that depletion of TbGS in blood-form parasites using a regulated knockout strategy leads to loss of trypanothione and to cell death as quantified by fluorescence-activated cell sorter (FACS) analysis. These data suggest that >97% depletion of TbGS is required before trypanothione is depleted and cell growth arrest is observed. Exogenous glutathione was able to partially compensate for the loss of TbGS, suggesting that parasites are able to transport intact glutathione. Finally, reduced expression of TbGS leads to increased levels of upstream glutathione biosynthetic enzymes and decreased expression of polyamine biosynthetic enzymes, providing evidence that the cells cross regulate the two branches of the trypanothione biosynthetic pathway to maintain spermidine and trypanothione homeostasis.
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Zimmermann S, Oufir M, Leroux A, Krauth-Siegel RL, Becker K, Kaiser M, Brun R, Hamburger M, Adams M. Cynaropicrin targets the trypanothione redox system in Trypanosoma brucei. Bioorg Med Chem 2013; 21:7202-9. [PMID: 24080104 DOI: 10.1016/j.bmc.2013.08.052] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 08/16/2013] [Accepted: 08/23/2013] [Indexed: 11/19/2022]
Abstract
In mice cynaropicrin (CYN) potently inhibits the proliferation of Trypanosoma brucei-the causative agent of Human African Trypanosomiasis-by a so far unknown mechanism. We hypothesized that CYNs α,β-unsaturated methylene moieties act as Michael acceptors for glutathione (GSH) and trypanothione (T(SH)2), the main low molecular mass thiols essential for unique redox metabolism of these parasites. The analysis of this putative mechanism and the effects of CYN on enzymes of the T(SH)2 redox metabolism including trypanothione reductase, trypanothione synthetase, glutathione-S-transferase, and ornithine decarboxylase are shown. A two step extraction protocol with subsequent UPLC-MS/MS analysis was established to quantify intra-cellular CYN, T(SH)2, GSH, as well as GS-CYN and T(S-CYN)2 adducts in intact T. b. rhodesiense cells. Within minutes of exposure to CYN, the cellular GSH and T(SH)2 pools were entirely depleted, and the parasites entered an apoptotic stage and died. CYN also showed inhibition of the ornithine decarboxylase similar to the positive control eflornithine. Significant interactions with the other enzymes involved in the T(SH)2 redox metabolism were not observed. Alongside many other biological activities sesquiterpene lactones including CYN have shown antitrypanosomal effects, which have been postulated to be linked to formation of Michael adducts with cellular nucleophiles. Here the interaction of CYN with biological thiols in a cellular system in general, and with trypanosomal T(SH)2 redox metabolism in particular, thus offering a molecular explanation for the antitrypanosomal activity is demonstrated. At the same time, the study provides a novel extraction and analysis protocol for components of the trypanosomal thiol metabolism.
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Affiliation(s)
- Stefanie Zimmermann
- Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland; Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
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26
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Alibu VP, Daunes S, D’Silva C. N-Benzyloxycarbonyl-S-(2,4-dinitrophenyl)glutathione dibutyl diester is inhibitory to melarsoprol resistant cell lines overexpressing the T. bruceiMRPA transporter. Bioorg Med Chem Lett 2013; 23:4351-3. [DOI: 10.1016/j.bmcl.2013.05.086] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 05/23/2013] [Accepted: 05/28/2013] [Indexed: 11/27/2022]
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Leroux AE, Haanstra JR, Bakker BM, Krauth-Siegel RL. Dissecting the catalytic mechanism of Trypanosoma brucei trypanothione synthetase by kinetic analysis and computational modeling. J Biol Chem 2013; 288:23751-64. [PMID: 23814051 PMCID: PMC3745322 DOI: 10.1074/jbc.m113.483289] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
In pathogenic trypanosomes, trypanothione synthetase (TryS) catalyzes the synthesis of both glutathionylspermidine (Gsp) and trypanothione (bis(glutathionyl)spermidine (T(SH)2)). Here we present a thorough kinetic analysis of Trypanosoma brucei TryS in a newly developed phosphate buffer system at pH 7.0 and 37 °C, mimicking the physiological environment of the enzyme in the cytosol of bloodstream parasites. Under these conditions, TryS displays Km values for GSH, ATP, spermidine, and Gsp of 34, 18, 687, and 32 μm, respectively, as well as Ki values for GSH and T(SH)2 of 1 mm and 360 μm, respectively. As Gsp hydrolysis has a Km value of 5.6 mm, the in vivo amidase activity is probably negligible. To obtain deeper insight in the molecular mechanism of TryS, we have formulated alternative kinetic models, with elementary reaction steps represented by linear kinetic equations. The model parameters were fitted to the extensive matrix of steady-state data obtained for different substrate/product combinations under the in vivo-like conditions. The best model describes the full kinetic profile and is able to predict time course data that were not used for fitting. This system's biology approach to enzyme kinetics led us to conclude that (i) TryS follows a ter-reactant mechanism, (ii) the intermediate Gsp dissociates from the enzyme between the two catalytic steps, and (iii) T(SH)2 inhibits the enzyme by remaining bound at its product site and, as does the inhibitory GSH, by binding to the activated enzyme complex. The newly detected concerted substrate and product inhibition suggests that TryS activity is tightly regulated.
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Affiliation(s)
- Alejandro E Leroux
- Biochemie-Zentrum der Universität Heidelberg, D-69120 Heidelberg, Germany
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28
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Abstract
The trypanosomes cause two neglected tropical diseases, Chagas disease in the Americas and African trypanosomiasis in sub-Saharan Africa. Over recent years a raft of molecular tools have been developed enabling the genetic dissection of many aspects of trypanosome biology, including the mechanisms underlying resistance to some of the current clinical and veterinary drugs. This has led to the identification and characterization of key resistance determinants, including transporters for the anti-Trypanosoma brucei drugs, melarsoprol, pentamidine and eflornithine, and the activator of nifurtimox-benznidazole, the anti-Trypanosoma cruzi drugs. More recently, advances in sequencing technology, combined with the development of RNA interference libraries in the clinically relevant bloodstream form of T. brucei have led to an exponential increase in the number of proteins known to interact either directly or indirectly with the anti-trypanosomal drugs. In this review, we discuss these findings and the technological developments that are set to further revolutionise our understanding of drug-trypanosome interactions. The new knowledge gained should inform the development of novel interventions against the devastating diseases caused by these parasites.
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Baker N, de Koning HP, Mäser P, Horn D. Drug resistance in African trypanosomiasis: the melarsoprol and pentamidine story. Trends Parasitol 2013; 29:110-8. [PMID: 23375541 PMCID: PMC3831158 DOI: 10.1016/j.pt.2012.12.005] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 12/16/2012] [Accepted: 12/17/2012] [Indexed: 01/07/2023]
Abstract
Melarsoprol and pentamidine represent the two main classes of drugs, the arsenicals and diamidines, historically used to treat the diseases caused by African trypanosomes: sleeping sickness in humans and Nagana in livestock. Cross-resistance to these drugs was first observed over 60 years ago and remains the only example of cross-resistance among sleeping sickness therapies. A Trypanosoma brucei adenosine transporter is well known for its role in the uptake of both drugs. More recently, aquaglyceroporin 2 (AQP2) loss of function was linked to melarsoprol-pentamidine cross-resistance. AQP2, a channel that appears to facilitate drug accumulation, may also be linked to clinical cases of resistance. Here, we review these findings and consider some new questions as well as future prospects for tackling the devastating diseases caused by these parasites.
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Affiliation(s)
- Nicola Baker
- London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Harry P. de Koning
- University of Glasgow, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow, G12 8TA, Scotland
| | - Pascal Mäser
- Swiss Tropical and Public Health Institute, Socinstr. 57, 4051 Basel, Switzerland
- University of Basel, Petersplatz 1, 4003 Basel, Switzerland
| | - David Horn
- London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
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The promiscuous binding of pharmaceutical drugs and their transporter-mediated uptake into cells: what we (need to) know and how we can do so. Drug Discov Today 2012. [PMID: 23207804 DOI: 10.1016/j.drudis.2012.11.008] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A recent paper in this journal sought to counter evidence for the role of transport proteins in effecting drug uptake into cells, and questions that transporters can recognize drug molecules in addition to their endogenous substrates. However, there is abundant evidence that both drugs and proteins are highly promiscuous. Most proteins bind to many drugs and most drugs bind to multiple proteins (on average more than six), including transporters (mutations in these can determine resistance); most drugs are known to recognise at least one transporter. In this response, we alert readers to the relevant evidence that exists or is required. This needs to be acquired in cells that contain the relevant proteins, and we highlight an experimental system for simultaneous genome-wide assessment of carrier-mediated uptake in a eukaryotic cell (yeast).
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Abstract
SIGNIFICANCE Parasitic infections continue to be a major problem for global human health. Vaccines are practically not available and chemotherapy is highly unsatisfactory. One approach toward a novel antiparasitic drug development is to unravel pathways that may be suited as future targets. Parasitic organisms show a remarkable diversity with respect to the nature and functions of their main low-molecular-mass antioxidants and many of them developed pathways that do not have a counterpart in their mammalian hosts. RECENT ADVANCES Work of the last years disclosed the individual antioxidants employed by parasites and their distinct pathways. Entamoeba, Trichomonas, and Giardia directly use cysteine as main low-molecular-mass thiol but have divergent cysteine metabolisms. Malarial parasites rely exclusively on cysteine uptake and generate glutathione (GSH) as main free thiol as do metazoan parasites. Trypanosomes and Leishmania have a unique trypanothione-based thiol metabolism but employ individual mechanisms for their cysteine supply. In addition, some trypanosomatids synthesize ovothiol A and/or ascorbate. Various essential parasite enzymes such as trypanothione synthetase and trypanothione reductase in Trypanosomatids and the Schistosoma thioredoxin GSH reductase are currently intensively explored as drug target molecules. CRITICAL ISSUES Essentiality is a prerequisite but not a sufficient property of an enzyme to become a suited drug target. The availability of an appropriate in vivo screening system and many other factors are equally important. FUTURE DIRECTIONS The current organism-wide RNA-interference and proteome analyses are supposed to reveal many more interesting candidates for future drug development approaches directed against the parasite antioxidant defense systems.
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Aquaglyceroporin 2 controls susceptibility to melarsoprol and pentamidine in African trypanosomes. Proc Natl Acad Sci U S A 2012; 109:10996-1001. [PMID: 22711816 DOI: 10.1073/pnas.1202885109] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
African trypanosomes cause sleeping sickness in humans, a disease that is typically fatal without chemotherapy. Unfortunately, drug resistance is common and melarsoprol-resistant trypanosomes often display cross-resistance to pentamidine. Although melarsoprol/pentamidine cross-resistance (MPXR) has been an area of intense interest for several decades, our understanding of the underlying mechanisms remains incomplete. Recently, a locus encoding two closely related aquaglyceroporins, AQP2 and AQP3, was linked to MPXR in a high-throughput loss-of-function screen. Here, we show that AQP2 has an unconventional "selectivity filter." AQP2-specific gene knockout generated MPXR trypanosomes but did not affect resistance to a lipophilic arsenical, whereas recombinant AQP2 reversed MPXR in cells lacking native AQP2 and AQP3. AQP2 was also shown to be disrupted in a laboratory-selected MPXR strain. Both AQP2 and AQP3 gained access to the surface plasma membrane in insect life-cycle-stage trypanosomes but, remarkably, AQP2 was specifically restricted to the flagellar pocket in the bloodstream stage. We conclude that the unconventional aquaglyceroporin, AQP2, renders cells sensitive to both melarsoprol and pentamidine and that loss of AQP2 function could explain cases of innate and acquired MPXR.
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Abstract
The ABC (ATP-binding cassette) protein superfamily is a ubiquitous and functionally versatile family of proteins that is conserved from archaea to humans. In eukaryotes, most of these proteins are implicated in the transport of a variety of molecules across cellular membranes, whereas the remaining ones are involved in biological processes unrelated to transport. The biological functions of several ABC proteins have been described in clinically important parasites and nematode worms and include vesicular trafficking, phospholipid movement, translation and drug resistance. This chapter reviews our current understanding of the role of ABC proteins in drug resistance and treatment failure in apicomplexan, trypanosomatid and amitochondriate parasites of medical relevance as well as in helminths.
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Jacobs RT, Nare B, Phillips MA. State of the art in African trypanosome drug discovery. Curr Top Med Chem 2011; 11:1255-74. [PMID: 21401507 PMCID: PMC3101707 DOI: 10.2174/156802611795429167] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Accepted: 11/25/2010] [Indexed: 11/22/2022]
Abstract
African sleeping sickness is endemic in sub-Saharan Africa where the WHO estimates that 60 million people are at risk for the disease. Human African trypanosomiasis (HAT) is 100% fatal if untreated and the current drug therapies have significant limitations due to toxicity and difficult treatment regimes. No new chemical agents have been approved since eflornithine in 1990. The pentamidine analog DB289, which was in late stage clinical trials for the treatment of early stage HAT recently failed due to toxicity issues. A new protocol for the treatment of late-stage T. brucei gambiense that uses combination nifurtomox/eflornithine (NECT) was recently shown to have better safety and efficacy than eflornithine alone, while being easier to administer. This breakthrough represents the only new therapy for HAT since the approval of eflornithine. A number of research programs are on going to exploit the unusual biochemical pathways in the parasite to identify new targets for target based drug discovery programs. HTS efforts are also underway to discover new chemical entities through whole organism screening approaches. A number of inhibitors with anti-trypanosomal activity have been identified by both approaches, but none of the programs are yet at the stage of identifying a preclinical candidate. This dire situation underscores the need for continued effort to identify new chemical agents for the treatment of HAT.
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Affiliation(s)
- Robert T. Jacobs
- SCYNEXIS, Inc., Research Triangle Park, North Carolina 27709-2878
| | - Bakela Nare
- SCYNEXIS, Inc., Research Triangle Park, North Carolina 27709-2878
| | - Margaret A. Phillips
- Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, 6001 Forest Park Rd, Dallas, Texas 75390-9041
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35
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Immunobiology of African trypanosomes: need of alternative interventions. J Biomed Biotechnol 2010; 2010:389153. [PMID: 20182644 PMCID: PMC2826769 DOI: 10.1155/2010/389153] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Revised: 10/29/2009] [Accepted: 12/23/2009] [Indexed: 02/08/2023] Open
Abstract
Trypanosomiasis is one of the major parasitic diseases for which control is still far from reality. The vaccination approaches by using dominant surface proteins have not been successful, mainly due to antigenic variation of the parasite surface coat. On the other hand, the chemotherapeutic drugs in current use for the treatment of this disease are toxic and problems of resistance are increasing (see Kennedy (2004) and Legros et al. (2002)). Therefore, alternative approaches in both treatment and vaccination against trypanosomiasis are needed at this time. To be able to design and develop such alternatives, the biology of this parasite and the host response against the pathogen need to be studied. These two aspects of this disease with few examples of alternative approaches are discussed here.
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Cuervo P, Domont GB, De Jesus JB. Proteomics of trypanosomatids of human medical importance. J Proteomics 2010; 73:845-67. [PMID: 20056176 DOI: 10.1016/j.jprot.2009.12.012] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2009] [Accepted: 12/18/2009] [Indexed: 12/31/2022]
Abstract
Leishmania spp., Trypanosoma cruzi, and Trypanosoma brucei are protozoan parasites that cause a spectrum of fatal human diseases around the world. Recent completion of the genomic sequencing of these parasites has enormous relevance to the study of their biology and the pathogenesis of the diseases they cause because it opens the door to high-throughput proteomic technologies. This review encompasses studies using diverse proteomic approaches with these organisms to describe and catalogue global protein profiles, reveal changes in protein expression during development, elucidate the subcellular localisation of gene products, and evaluate host-parasite interactions.
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Affiliation(s)
- Patricia Cuervo
- Laboratorio de Pesquisa em Leishmaniose, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
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Abstract
The protozoan parasitesTrypanosoma bruceiandTrypanosoma cruziare the causative agents of African trypanosomiasis and Chagas disease, respectively. These are debilitating infections that exert a considerable health burden on some of the poorest people on the planet. Treatment of trypanosome infections is dependent on a small number of drugs that have limited efficacy and can cause severe side effects. Here, we review the properties of these drugs and describe new findings on their modes of action and the mechanisms by which resistance can arise. We further outline how a greater understanding of parasite biology is being exploited in the search for novel chemotherapeutic agents. This effort is being facilitated by new research networks that involve academic and biotechnology/pharmaceutical organisations, supported by public–private partnerships, and are bringing a new dynamism and purpose to the search for trypanocidal agents.
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Comini MA, Dirdjaja N, Kaschel M, Krauth-Siegel RL. Preparative enzymatic synthesis of trypanothione and trypanothione analogues. Int J Parasitol 2009; 39:1059-62. [PMID: 19477177 DOI: 10.1016/j.ijpara.2009.05.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Revised: 05/12/2009] [Accepted: 05/13/2009] [Indexed: 10/20/2022]
Abstract
Trypanosomatids, the causative agents of several tropical diseases, have a unique thiol metabolism based on trypanothione [bis(glutathionyl)spermidine]. Enzymes of the pathway are attractive drug target molecules but the availability of trypanothione remains an obstacle. Here, we present a convenient method for the production of trypanothione and trypanothione disulfide in >200mg quantities using a mutant of Crithidia fasciculata trypanothione synthetase in which Cys59 has been replaced by an alanine residue. The reagent costs less than 1% of the commercial price of trypanothione disulfide. The protocol also allows the synthesis of related glutathione conjugates. It will greatly facilitate the thorough analysis of this parasite's metabolism and drug screening approaches against trypanothione-dependent enzymes.
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Affiliation(s)
- Marcelo A Comini
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 504, 69120 Heidelberg, Germany
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39
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Sauvage V, Aubert D, Escotte-Binet S, Villena I. The role of ATP-binding cassette (ABC) proteins in protozoan parasites. Mol Biochem Parasitol 2009; 167:81-94. [PMID: 19464325 DOI: 10.1016/j.molbiopara.2009.05.005] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2009] [Revised: 05/11/2009] [Accepted: 05/12/2009] [Indexed: 10/20/2022]
Abstract
The ATP-binding cassette (ABC) superfamily is one of the largest protein families with representatives in all kingdoms of life. Members of this superfamily are involved in a wide variety of transport processes with substrates ranging from small ions to relatively large polypeptides and polysaccharides, but also in cellular processes such as DNA repair, translation or regulation of gene expression. For many years, the role of ABC proteins was mainly investigated for their implication in drug resistance. However, recent studies focused rather on their physiological functions for the parasite. In this review, we present an overview of ABC proteins in major protozoan parasites including Leishmania, Trypanosoma, Plasmodium, Toxoplasma, Cryptosporidium and Entamoeba species. We will also discuss the role of characterized ABC transporters in the biology of the parasite and in drug resistance.
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Affiliation(s)
- Virginie Sauvage
- Laboratoire de Parasitologie-Mycologie, EA 3800, IFR 53, UFR Médecine, Université de Reims Champagne-Ardenne, 51 rue Cognacq-Jay, 51095 Reims Cedex, France
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40
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González-Pons M, Szeto AC, González-Méndez R, Serrano AE. Identification and bioinformatic characterization of a multidrug resistance associated protein (ABCC) gene in Plasmodium berghei. Malar J 2009; 8:1. [PMID: 19118502 PMCID: PMC2630995 DOI: 10.1186/1475-2875-8-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2008] [Accepted: 01/02/2009] [Indexed: 11/25/2022] Open
Abstract
Background The ATP-binding cassette (ABC) superfamily is one of the largest evolutionarily conserved families of proteins. ABC proteins play key roles in cellular detoxification of endobiotics and xenobiotics. Overexpression of certain ABC proteins, among them the multidrug resistance associated protein (MRP), contributes to drug resistance in organisms ranging from human neoplastic cells to parasitic protozoa. In the present study, the Plasmodium berghei mrp gene (pbmrp) was partially characterized and the predicted protein was classified using bioinformatics in order to explore its putative involvement in drug resistance. Methods The pbmrp gene from the P. berghei drug sensitive, N clone, was sequenced using a PCR strategy. Classification and domain organization of pbMRP were determined with bioinformatics. The Plasmodium spp. MRPs were aligned and analysed to study their conserved motifs and organization. Gene copy number and organization were determined via Southern blot analysis in both N clone and the chloroquine selected line, RC. Chromosomal Southern blots and RNase protection assays were employed to determine the chromosomal location and expression levels of pbmrp in blood stages. Results The pbmrp gene is a single copy, intronless gene with a predicted open reading frame spanning 5820 nucleotides. Bioinformatic analyses show that this protein has distinctive features characteristic of the ABCC sub-family. Multiple sequence alignments reveal a high degree of conservation in the nucleotide binding and transmembrane domains within the MRPs from the Plasmodium spp. analysed. Expression of pbmrp was detected in asexual blood stages. Gene organization, copy number and mRNA expression was similar in both lines studied. A chromosomal translocation was observed in the chloroquine selected RC line, from chromosome 13/14 to chromosome 8, when compared to the drug sensitive N clone. Conclusion In this study, the pbmrp gene was sequenced and classified as a member of the ABCC sub-family. Multiple sequence alignments reveal that this gene is homologous to the Plasmodium y. yoelii and Plasmodium knowlesi mrp, and the Plasmodium vivax and Plasmodium falciparum mrp2 genes. There were no differences in gene organization, copy number, or mRNA expression between N clone and the RC line, but a chromosomal translocation of pbmrp from chromosome 13/14 to chromosome 8 was detected in RC.
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Affiliation(s)
- María González-Pons
- Department of Microbiology, University of Puerto Rico School of Medicine, PO Box 365067, San Juan, PR 00936-5067, USA.
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Metabolic control analysis: a tool for designing strategies to manipulate metabolic pathways. J Biomed Biotechnol 2008; 2008:597913. [PMID: 18629230 PMCID: PMC2447884 DOI: 10.1155/2008/597913] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Revised: 01/16/2008] [Accepted: 03/26/2008] [Indexed: 02/06/2023] Open
Abstract
The traditional experimental approaches used for changing the flux or the concentration of a particular metabolite of a metabolic pathway have been mostly based on the inhibition or over-expression of the presumed rate-limiting step. However, the attempts to manipulate a metabolic pathway by following such approach have proved to be unsuccessful. Metabolic Control Analysis (MCA) establishes how to determine, quantitatively, the degree of control that a given enzyme exerts on flux and on the concentration of metabolites, thus substituting the intuitive, qualitative concept of rate limiting step. Moreover, MCA helps to understand (i) the underlying mechanisms by which a given enzyme exerts high or low control and (ii) why the control of the pathway is shared by several pathway enzymes and transporters. By applying MCA it is possible to identify the steps that should be modified to achieve a successful alteration of flux or metabolite concentration in pathways of biotechnological (e.g., large scale metabolite production) or clinical relevance (e.g., drug therapy). The different MCA experimental approaches developed for the determination of the flux-control distribution in several pathways are described. Full understanding of the pathway properties when is working under a variety of conditions can help to attain a successful manipulation of flux and metabolite concentration.
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Ever-increasing complexities of diamidine and arsenical crossresistance in African trypanosomes. Trends Parasitol 2008; 24:345-9. [DOI: 10.1016/j.pt.2008.04.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Revised: 04/08/2008] [Accepted: 04/08/2008] [Indexed: 10/21/2022]
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Krauth-Siegel RL, Comini MA. Redox control in trypanosomatids, parasitic protozoa with trypanothione-based thiol metabolism. Biochim Biophys Acta Gen Subj 2008; 1780:1236-48. [PMID: 18395526 DOI: 10.1016/j.bbagen.2008.03.006] [Citation(s) in RCA: 291] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Revised: 02/26/2008] [Accepted: 03/11/2008] [Indexed: 01/09/2023]
Abstract
Trypanosomes and leishmania, the causative agents of several tropical diseases, possess a unique redox metabolism which is based on trypanothione. The bis(glutathionyl)spermidine is the central thiol that delivers electrons for the synthesis of DNA precursors, the detoxification of hydroperoxides and other trypanothione-dependent pathways. Many of the reactions are mediated by tryparedoxin, a distant member of the thioredoxin protein family. Trypanothione is kept reduced by the parasite-specific flavoenzyme trypanothione reductase. Since glutathione reductases and thioredoxin reductases are missing, the reaction catalyzed by trypanothione reductase represents the only connection between the NADPH- and the thiol-based redox metabolisms. Thus, cellular thiol redox homeostasis is maintained by the biosynthesis and reduction of trypanothione. Nearly all proteins of the parasite-specific trypanothione metabolism have proved to be essential.
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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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Comini MA, Krauth-Siegel RL, Flohé L. Depletion of the thioredoxin homologue tryparedoxin impairs antioxidative defence in African trypanosomes. Biochem J 2007; 402:43-9. [PMID: 17040206 PMCID: PMC1783994 DOI: 10.1042/bj20061341] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In trypanosomes, the thioredoxin-type protein TXN (tryparedoxin) is a multi-purpose oxidoreductase that is involved in the detoxification of hydroperoxides, the synthesis of DNA precursors and the replication of the kinetoplastid DNA. African trypanosomes possess two isoforms that are localized in the cytosol and in the mitochondrion of the parasites respectively. Here we report on the biological significance of the cTXN (cytosolic TXN) of Trypanosoma brucei for hydroperoxide detoxification. Depending on the growth phase, the concentration of the protein is 3-7-fold higher in the parasite form infecting mammals (50-100 microM) than in the form hosted by the tsetse fly (7-34 microM). Depletion of the mRNA in bloodstream trypanosomes by RNA interference revealed the indispensability of the protein. Proliferation and viability of cultured trypanosomes were impaired when TXN was lowered to 1 muM for more than 48 h. Although the levels of glutathione, glutathionylspermidine and trypanothione were increased 2-3.5-fold, the sensitivity against exogenously generated H2O2 was significantly enhanced. The results prove the essential role of the cTXN and its pivotal function in the parasite defence against oxidative stress.
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Affiliation(s)
- Marcelo A Comini
- Centre of Biochemistry, Heidelberg University, Im Neuenheimer Feld 504, D-69120, Heidelberg, Germany.
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Melchers J, Dirdjaja N, Ruppert T, Krauth-Siegel RL. Glutathionylation of Trypanosomal Thiol Redox Proteins. J Biol Chem 2007; 282:8678-94. [PMID: 17242409 DOI: 10.1074/jbc.m608140200] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Trypanosomatids, the causative agents of several tropical diseases, lack glutathione reductase and thioredoxin reductase but have a trypanothione reductase instead. The main low molecular weight thiols are trypanothione (N(1),N(8)-bis-(glutathionyl)spermidine) and glutathionyl-spermidine, but the parasites also contain free glutathione. To elucidate whether trypanosomes employ S-thiolation for regulatory or protection purposes, six recombinant parasite thiol redox proteins were studied by ESI-MS and MALDI-TOF-MS for their ability to form mixed disulfides with glutathione or glutathionylspermidine. Trypanosoma brucei mono-Cys-glutaredoxin 1 is specifically thiolated at Cys(181). Thiolation of this residue induced formation of an intramolecular disulfide bridge with the putative active site Cys(104). This contrasts with mono-Cys-glutaredoxins from other sources that have been reported to be glutathionylated at the active site cysteine. Both disulfide forms of the T. brucei protein were reduced by tryparedoxin and trypanothione, whereas glutathione cleaved only the protein disulfide. In the glutathione peroxidase-type tryparedoxin peroxidase III of T. brucei, either Cys(47) or Cys(95) became glutathionylated but not both residues in the same protein molecule. T. brucei thioredoxin contains a third cysteine (Cys(68)) in addition to the redox active dithiol/disulfide. Treatment of the reduced protein with GSSG caused glutathionylation of Cys(68), which did not affect its capacity to catalyze reduction of insulin disulfide. Reduced T. brucei tryparedoxin possesses only the redox active Cys(32)-Cys(35) couple, which upon reaction with GSSG formed a disulfide. Also glyoxalase II and Trypanosoma cruzi trypanothione reductase were not sensitive to thiolation at physiological GSSG concentrations.
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Bridges DJ, Gould MK, Nerima B, Mäser P, Burchmore RJS, de Koning HP. Loss of the high-affinity pentamidine transporter is responsible for high levels of cross-resistance between arsenical and diamidine drugs in African trypanosomes. Mol Pharmacol 2007; 71:1098-108. [PMID: 17234896 DOI: 10.1124/mol.106.031351] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Treatment of many infectious diseases is under threat from drug resistance. Understanding the mechanisms of resistance is as high a priority as the development of new drugs. We have investigated the basis for cross-resistance between the diamidine and melaminophenyl arsenical classes of drugs in African trypanosomes. We induced high levels of pentamidine resistance in a line without the tbat1 gene that encodes the P2 transporter previously implicated in drug uptake. We isolated independent clones that displayed very considerable cross-resistance with melarsen oxide but not phenylarsine oxide and reduced uptake of [(3)H]pentamidine. In particular, the high-affinity pentamidine transport (HAPT1) activity was absent in the pentamidine-adapted lines, whereas the low affinity pentamidine transport (LAPT1) activity was unchanged. The parental tbat1(-/-) line was sensitive to lysis by melarsen oxide, and this process was inhibited by low concentrations of pentamidine, indicating the involvement of HAPT1. This pentamidine-inhibitable lysis was absent in the adapted line KO-B48. Likewise, uptake of the fluorescent diamidine 4',6-diamidino-2-phenylindole dihydrochloride was much delayed in live KO-B48 cells and insensitive to competition with up to 10 muM pentamidine. No overexpression of the Trypanosoma brucei brucei ATP-binding cassette transporter TbMRPA could be detected in KO-B48. We also show that a laboratory line of Trypanosoma brucei gambiense, adapted to high levels of resistance for the melaminophenyl arsenical drug melarsamine hydrochloride (Cymelarsan), had similarly lost TbAT1 and HAPT1 activity while retaining LAPT1 activity. It seems therefore that selection for resistance to either pentamidine or arsenical drugs can result in a similar phenotype of reduced drug accumulation, explaining the occurrence of cross-resistance.
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Affiliation(s)
- Daniel J Bridges
- Institute of Biomedical and Life Sciences, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow G12 8TA, United Kingdom
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48
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Abstract
Trypanosomes and Leishmania, the causative agents of severe tropical diseases, employ 2-Cys-peroxiredoxins together with cysteine-homologues of glutathione peroxidases and ascorbate-dependent peroxidases for the detoxification of hydroperoxides. All three types of peroxidases gain their reducing equivalents from the parasite-specific dithiol trypanothione [bis(glutathionyl)spermidine]. Based on their primary structure and cellular localization, the trypanosomatid 2-Cys-peroxiredoxins are subdivided into two families that occur in the mitochondrion and cytosol of the parasites. In Trypanosoma brucei, the cytosolic 2-Cys-peroxiredoxin, as well as the glutathione peroxidase-type enzyme, is essential for cell viability. Despite overlapping substrate specificities and subcellular localizations, the two types of peroxidases can obviously not substitute for each other which suggests distinct cell-physiological roles.
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Barrett MP, Gilbert IH. Targeting of toxic compounds to the trypanosome's interior. ADVANCES IN PARASITOLOGY 2006; 63:125-83. [PMID: 17134653 DOI: 10.1016/s0065-308x(06)63002-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Drugs can be targeted into African trypanosomes by exploiting carrier proteins at the surface of these parasites. This has been clearly demonstrated in the case of the melamine-based arsenical and the diamidine classes of drug that are already in use in the treatment of human African trypanosomiasis. These drugs can enter via an aminopurine transporter, termed P2, encoded by the TbAT1 gene. Other toxic compounds have also been designed to enter via this transporter. Some of these compounds enter almost exclusively through the P2 transporter, and hence loss of the P2 transporter leads to significant resistance to these particular compounds. It now appears, however, that some diamidines and melaminophenylarsenicals may also be taken up by other routes (of yet unknown function). These too may be exploited to target new drugs into trypanosomes. Additional purine nucleoside and nucleobase transporters have also been subverted to deliver toxic agents to trypanosomes. Glucose and amino acid transporters too have been investigated with a view to manipulating them to carry toxins into Trypanosoma brucei, and recent work has demonstrated that aquaglyceroporins may also have considerable potential for drug-targeting. Transporters, including those that carry lipids and vitamins such as folate and other pterins also deserve more attention in this regard. Some drugs, for example suramin, appear to enter via routes other than plasma-membrane-mediated transport. Receptor-mediated endocytosis has been proposed as a possible way in for suramin. Endocytosis also appears to be crucial in targeting natural trypanocides, such as trypanosome lytic factor (TLF) (apolipoprotein L1), into trypanosomes and this offers an alternative means of selectively targeting toxins to the trypanosome's interior. Other compounds may be induced to enter by increasing their capacity to diffuse over cell membranes; in this case depending exclusively on selective activity within the cell rather than selective uptake to impart selective toxicity. This review outlines studies that have aimed to exploit trypanosome nutrient uptake routes to selectively carry toxins into these parasites.
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Affiliation(s)
- Michael P Barrett
- Division of Infection & Immunity, Institute of Biomedical and Life Sciences, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow G12 8QQ, UK
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50
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Lüscher A, Nerima B, Mäser P. Combined contribution of TbAT1 and TbMRPA to drug resistance in Trypanosoma brucei. Mol Biochem Parasitol 2006; 150:364-6. [PMID: 16935360 DOI: 10.1016/j.molbiopara.2006.07.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2006] [Revised: 07/18/2006] [Accepted: 07/20/2006] [Indexed: 11/26/2022]
Affiliation(s)
- Alexandra Lüscher
- University of Bern, Institute of Cell Biology, Baltzerstrasse 4, 3012 Bern, Switzerland
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