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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] [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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Okello I, Nzalawahe J, Mafie E, Eastwood G. Seasonal variation in tsetse fly apparent density and Trypanosoma spp. infection rate and occurrence of drug-resistant trypanosomes in Lambwe, Kenya. Parasitol Res 2023; 123:46. [PMID: 38095710 DOI: 10.1007/s00436-023-08081-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 11/29/2023] [Indexed: 12/18/2023]
Abstract
Tsetse flies are major arthropod vectors of trypanosomes that cause debilitating African animal trypanosomiasis. The emergence of drug-resistant trypanosomes is a common problem in sub-Saharan Africa. This study aimed to identify tsetse flies' seasonal variation in apparent densities and their infection rates and the occurrence of drug-resistant trypanosomes. Tsetse flies were collected from Lambwe, Kenya, during May and September 2021. Genomic DNA was extracted from them, and the ITS1 gene was amplified to detect Trypanosoma infection with subsequent species determination. Transporter genes DMT, E6M6, TbAT/P2, and TcoAde2 were targeted to detect polymorphisms associated with drug-resistance, using sequencing and comparison to drug-sensitive trypanosome species referenced in Genbank. A total of 498 tsetse flies and 29 non-tsetse flies were collected. The apparent density of flies was higher in wet season 6.2 fly per trap per density (FTD) than in the dry season 2.3 FTD (P = 0.001), with n = 386 and n = 141 flies caught in each season, respectively. Male tsetse flies (n = 311) were more numerous than females (n = 187) (P = 0.001). Non-tsetse flies included Tabanids and Stomoxys spp. Overall, Trypanosoma infection rate in tsetse was 5% (25/498) whereby Trypanosoma vivax was 4% (11/25), Trypanosoma congolense 36% (9/25), and Trypanosoma brucei 20% (5/25) (P = 0.186 for the distribution of the species), with infections being higher in females (P = 0.019) and during the wet season (P < 0.001). Numerous polymorphisms and insertions associated with drug resistance were detected in DMT and E6M6 genes in two T. congolense isolates while some isolates lacked these genes. T. brucei lacked TbAT/P2 genes. TcoAde2 sequences in three T. congolense isolates were related to those observed in trypanosomes from cattle blood in our previous study, supporting tsetse fly involvement in transmission in the region. We report Trypanosoma associated with trypanocidal drug-resistance in tsetse flies from Lambwe, Kenya. Female tsetse flies harbored more Trypanosoma infections than males. Tsetse transmission of trypanosomes is common in Lambwe. Risk of trypanosome infection would seem higher in the wet season, when tsetse flies and Trypanosoma infections are more prevalent than during the dry season. More efforts to control animal trypanosome vectors in the region are needed, with particular focus on wet seasons.
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Affiliation(s)
- Ivy Okello
- Department of Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Chuo Kikuu, P.O. Box 3019, Morogoro, Tanzania.
- Africa Centre of Excellence for Infectious Diseases of Humans and Animals in Eastern and Southern Africa, SACIDS Foundation for One Health, P.O. Box 3297, Morogoro, Tanzania.
- Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA.
| | - Jahashi Nzalawahe
- Department of Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Chuo Kikuu, P.O. Box 3019, Morogoro, Tanzania
| | - Eliakunda Mafie
- Department of Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Chuo Kikuu, P.O. Box 3019, Morogoro, Tanzania
| | - Gillian Eastwood
- Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA
- The Global Change Center at Virginia Tech, Blacksburg, VA, 24061, USA
- Center for Emerging, Zoonotic, and Arthropod-borne Pathogens (CeZAP), Virginia Tech, Blacksburg, VA, USA
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Ungogo MA, Aldfer MM, Natto MJ, Zhuang H, Chisholm R, Walsh K, McGee M, Ilbeigi K, Asseri JI, Burchmore RJS, Caljon G, Van Calenbergh S, De Koning HP. Cloning and Characterization of Trypanosoma congolense and T. vivax Nucleoside Transporters Reveal the Potential of P1-Type Carriers for the Discovery of Broad-Spectrum Nucleoside-Based Therapeutics against Animal African Trypanosomiasis. Int J Mol Sci 2023; 24:ijms24043144. [PMID: 36834557 PMCID: PMC9960827 DOI: 10.3390/ijms24043144] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 02/01/2023] [Accepted: 02/02/2023] [Indexed: 02/09/2023] Open
Abstract
African Animal Trypanosomiasis (AAT), caused predominantly by Trypanosoma brucei brucei, T. vivax and T. congolense, is a fatal livestock disease throughout Sub-Saharan Africa. Treatment options are very limited and threatened by resistance. Tubercidin (7-deazaadenosine) analogs have shown activity against individual parasites but viable chemotherapy must be active against all three species. Divergence in sensitivity to nucleoside antimetabolites could be caused by differences in nucleoside transporters. Having previously characterized the T. brucei nucleoside carriers, we here report the functional expression and characterization of the main adenosine transporters of T. vivax (TvxNT3) and T. congolense (TcoAT1/NT10), in a Leishmania mexicana cell line ('SUPKO') lacking adenosine uptake. Both carriers were similar to the T. brucei P1-type transporters and bind adenosine mostly through interactions with N3, N7 and 3'-OH. Expression of TvxNT3 and TcoAT1 sensitized SUPKO cells to various 7-substituted tubercidins and other nucleoside analogs although tubercidin itself is a poor substrate for P1-type transporters. Individual nucleoside EC50s were similar for T. b. brucei, T. congolense, T. evansi and T. equiperdum but correlated less well with T. vivax. However, multiple nucleosides including 7-halogentubercidines displayed pEC50>7 for all species and, based on transporter and anti-parasite SAR analyses, we conclude that nucleoside chemotherapy for AAT is viable.
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Affiliation(s)
- Marzuq A. Ungogo
- School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
- Department of Veterinary Pharmacology and Toxicology, Ahmadu Bello University, Zaria 810107, Kaduna State, Nigeria
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian EH25 9RG, UK
| | - Mustafa M. Aldfer
- School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
| | - Manal J. Natto
- School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
| | - Hainan Zhuang
- School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
| | - Robyn Chisholm
- School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
| | - Katy Walsh
- School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
| | - MarieClaire McGee
- School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
| | - Kayhan Ilbeigi
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, B-2610 Wilrijk, Belgium
| | - Jamal Ibrahim Asseri
- School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
| | - Richard J. S. Burchmore
- School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
| | - Guy Caljon
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, B-2610 Wilrijk, Belgium
| | - Serge Van Calenbergh
- Laboratory for Medicinal Chemistry (Campus Heymans), Ghent University, B-9000 Gent, Belgium
| | - Harry P. De Koning
- School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
- Correspondence:
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The Trypanosoma cruzi TcrNT2 Nucleoside Transporter Is a Conduit for the Uptake of 5-F-2'-Deoxyuridine and Tubercidin Analogues. Molecules 2022; 27:molecules27228045. [PMID: 36432150 PMCID: PMC9693223 DOI: 10.3390/molecules27228045] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 11/14/2022] [Accepted: 11/17/2022] [Indexed: 11/22/2022] Open
Abstract
Among the scarce validated drug targets against Chagas disease (CD), caused by Trypanosoma cruzi, the parasite's nucleoside salvage system has recently attracted considerable attention. Although the trypanocidal activity of tubercidin (7-deazapurine) has long been known, the identification of a class of 7-substituted tubercidin analogs with potent in vitro and in vivo activity and much-enhanced selectivity has made nucleoside analogs among the most promising lead compounds against CD. Here, we investigate the recently identified TcrNT2 nucleoside transporter and its potential role in antimetabolite chemotherapy. TcrNT2, expressed in a Leishmania mexicana cell line lacking the NT1 nucleoside transporter locus, displayed very high selectivity and affinity for thymidine with a Km of 0.26 ± 0.05 µM. The selectivity was explained by interactions of 2-oxo, 4-oxo, 5-Me, 3'-hydroxy and 5'-hydroxy with the transporter binding pocket, whereas a hydroxy group at the 2' position was deleterious to binding. This made 5-halogenated 2'-deoxyuridine analogues good substrates but 5-F-2'-deoxyuridine displayed disappointing activity against T. cruzi trypomastigotes. By comparing the EC50 values of tubercidin and its 7-substituted analogues against L. mexicana Cas9, Cas9ΔNT1 and Cas9ΔNT1+TcrNT2 it was shown that TcrNT2 can take up tubercidin and, at a minimum, a subset of the analogs.
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Kasozi KI, MacLeod ET, Welburn SC. Systematic Review and Meta-Analysis on Human African Trypanocide Resistance. Pathogens 2022; 11:pathogens11101100. [PMID: 36297157 PMCID: PMC9612373 DOI: 10.3390/pathogens11101100] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 09/14/2022] [Accepted: 09/20/2022] [Indexed: 11/16/2022] Open
Abstract
Background Human African trypanocide resistance (HATr) is a challenge for the eradication of Human African Trypansomiaisis (HAT) following the widespread emergence of increased monotherapy drug treatment failures against Trypanosoma brucei gambiense and T. b. rhodesiense that are associated with changes in pathogen receptors. Methods: Electronic searches of 12 databases and 3 Google search websites for human African trypanocide resistance were performed using a keyword search criterion applied to both laboratory and clinical studies. Fifty-one publications were identified and included in this study using the PRISMA checklist. Data were analyzed using RevMan and random effect sizes were computed for the statistics at the 95% confidence interval. Results: Pentamidine/melarsoprol/nifurtimox cross-resistance is associated with loss of the T. brucei adenosine transporter 1/purine 2 gene (TbAT1/P2), aquaglyceroporins (TbAQP) 2 and 3, followed by the high affinity pentamidine melarsoprol transporter (HAPT) 1. In addition, the loss of the amino acid transporter (AAT) 6 is associated with eflornithine resistance. Nifurtimox/eflornithine combination therapy resistance is associated with AAT6 and nitroreductase loss, and high resistance and parasite regrowth is responsible for treatment relapse. In clinical studies, the TbAT1 proportion of total random effects was 68% (95% CI: 38.0−91.6); I2 = 96.99% (95% CI: 94.6−98.3). Treatment failure rates were highest with melarsoprol followed by eflornithine at 41.49% (95% CI: 24.94−59.09) and 6.56% (3.06−11.25) respectively. HATr-resistant phenotypes used in most laboratory experiments demonstrated significantly higher pentamidine resistance than other trypanocides. Conclusion: The emergence of drug resistance across the spectrum of trypanocidal agents that are used to treat HAT is a major threat to the global WHO target to eliminate HAT by 2030. T. brucei strains were largely resistant to diamidines and the use of high trypanocide concentrations in clinical studies have proved fatal in humans. Studies to develop novel chemotherapeutical agents and identify alternative protein targets could help to reduce the emergence and spread of HATr.
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Affiliation(s)
- Keneth Iceland Kasozi
- Infection Medicine, Deanery of Biomedical Sciences, Edinburgh Medical School, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh EH8 9JZ, UK
- School of Medicine, Kabale University, Kabale P.O. Box 317, Uganda
- Correspondence: (K.I.K.); (S.C.W.)
| | - Ewan Thomas MacLeod
- Infection Medicine, Deanery of Biomedical Sciences, Edinburgh Medical School, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh EH8 9JZ, UK
| | - Susan Christina Welburn
- Infection Medicine, Deanery of Biomedical Sciences, Edinburgh Medical School, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh EH8 9JZ, UK
- Zhejiang University-University of Edinburgh Joint Institute, Zhejiang University, International Campus, 718 East Haizhou Road, Haining 314400, China
- Correspondence: (K.I.K.); (S.C.W.)
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Nucleoside Transport and Nucleobase Uptake Null Mutants in Leishmania mexicana for the Routine Expression and Characterization of Purine and Pyrimidine Transporters. Int J Mol Sci 2022; 23:ijms23158139. [PMID: 35897714 PMCID: PMC9331716 DOI: 10.3390/ijms23158139] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/05/2022] [Accepted: 07/20/2022] [Indexed: 12/02/2022] Open
Abstract
The study of transporters is highly challenging, as they cannot be isolated or studied in suspension, requiring a cellular or vesicular system, and, when mediated by more than one carrier, difficult to interpret. Nucleoside analogues are important drug candidates, and all protozoan pathogens express multiple equilibrative nucleoside transporter (ENT) genes. We have therefore developed a system for the routine expression of nucleoside transporters, using CRISPR/cas9 to delete both copies of all three nucleoside transporters from Leishmania mexicana (ΔNT1.1/1.2/2 (SUPKO)). SUPKO grew at the same rate as the parental strain and displayed no apparent deficiencies, owing to the cells’ ability to synthesize pyrimidines, and the expression of the LmexNT3 purine nucleobase transporter. Nucleoside transport was barely measurable in SUPKO, but reintroduction of L. mexicana NT1.1, NT1.2, and NT2 restored uptake. Thus, SUPKO provides an ideal null background for the expression and characterization of single ENT transporter genes in isolation. Similarly, an LmexNT3-KO strain provides a null background for transport of purine nucleobases and was used for the functional characterization of T. cruzi NB2, which was determined to be adenine-specific. A 5-fluorouracil-resistant strain (Lmex5FURes) displayed null transport for uracil and 5FU, and was used to express the Aspergillus nidulans uracil transporter FurD.
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Kasozi KI, MacLeod ET, Ntulume I, Welburn SC. An Update on African Trypanocide Pharmaceutics and Resistance. Front Vet Sci 2022; 9:828111. [PMID: 35356785 PMCID: PMC8959112 DOI: 10.3389/fvets.2022.828111] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 01/12/2022] [Indexed: 12/22/2022] Open
Abstract
African trypanosomiasis is associated with Trypanosoma evansi, T. vivax, T. congolense, and T. brucei pathogens in African animal trypanosomiasis (AAT) while T. b gambiense and T. b rhodesiense are responsible for chronic and acute human African trypanosomiasis (HAT), respectively. Suramin sodium suppresses ATP generation during the glycolytic pathway and is ineffective against T. vivax and T. congolense infections. Resistance to suramin is associated with pathogen altered transport proteins. Melarsoprol binds irreversibly with pyruvate kinase protein sulfhydryl groups and neutralizes enzymes which interrupts the trypanosome ATP generation. Melarsoprol resistance is associated with the adenine-adenosine transporter, P2, due to point mutations within this transporter. Eflornithine is used in combination with nifurtimox. Resistance to eflornithine is caused by the deletion or mutation of TbAAT6 gene which encodes the transmembrane amino acid transporter that delivers eflornithine into the cell, thus loss of transporter protein results in eflornithine resistance. Nifurtimox alone is regarded as a poor trypanocide, however, it is effective in melarsoprol-resistant gHAT patients. Resistance is associated with loss of a single copy of the genes encoding for nitroreductase enzymes. Fexinidazole is recommended for first-stage and non-severe second-stage illnesses in gHAT and resistance is associated with trypanosome bacterial nitroreductases which reduce fexinidazole. In AAT, quinapyramine sulfate interferes with DNA synthesis and suppression of cytoplasmic ribosomal activity in the mitochondria. Quinapyramine sulfate resistance is due to variations in the potential of the parasite's mitochondrial membrane. Pentamidines create cross-links between two adenines at 4–5 pairs apart in adenine-thymine-rich portions of Trypanosoma DNA. It also suppresses type II topoisomerase in the mitochondria of Trypanosoma parasites. Pentamidine resistance is due to loss of mitochondria transport proteins P2 and HAPT1. Diamidines are most effective against Trypanosome brucei group and act via the P2/TbAT1 transporters. Diminazene aceturate resistance is due to mutations that alter the activity of P2, TeDR40 (T. b. evansi). Isometamidium chloride is primarily employed in the early stages of trypanosomiasis and resistance is associated with diminazene resistance. Phenanthridine (homidium bromide, also known as ethidium bromide) acts by a breakdown of the kinetoplast network and homidium resistance is comparable to isometamidium. In humans, the development of resistance and adverse side effects against monotherapies has led to the adoption of nifurtimox-eflornithine combination therapy. Current efforts to develop new prodrug combinations of nifurtimox and eflornithine and nitroimidazole fexinidazole as well as benzoxaborole SCYX-7158 (AN5568) for HAT are in progress while little comparable progress has been done for the development of novel therapies to address trypanocide resistance in AAT.
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Affiliation(s)
- Keneth Iceland Kasozi
- Infection Medicine, Deanery of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
- School of Medicine, Kabale University, Kabale, Uganda
- *Correspondence: Keneth Iceland Kasozi ;
| | - Ewan Thomas MacLeod
- Infection Medicine, Deanery of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
| | - Ibrahim Ntulume
- School of Biosecurity Biotechnical and Laboratory Sciences, College of Medicine and Veterinary Medicine, Makerere University, Kampala, Uganda
| | - Susan Christina Welburn
- Infection Medicine, Deanery of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
- Zhejiang University-University of Edinburgh Joint Institute, Zhejiang University, Hangzhou, China
- Susan Christina Welburn
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Differences in Transporters Rather than Drug Targets Are the Principal Determinants of the Different Innate Sensitivities of Trypanosoma congolense and Trypanozoon Subgenus Trypanosomes to Diamidines and Melaminophenyl Arsenicals. Int J Mol Sci 2022; 23:ijms23052844. [PMID: 35269985 PMCID: PMC8911344 DOI: 10.3390/ijms23052844] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/02/2022] [Accepted: 03/03/2022] [Indexed: 12/24/2022] Open
Abstract
The animal trypanosomiases are infections in a wide range of (domesticated) animals with any species of African trypanosome, such as Trypanosoma brucei, T. evansi, T. congolense, T. equiperdum and T. vivax. Symptoms differ between host and infective species and stage of infection and are treated with a small set of decades-old trypanocides. A complication is that not all trypanosome species are equally sensitive to all drugs and the reasons are at best partially understood. Here, we investigate whether drug transporters, mostly identified in T. b. brucei, determine the different drug sensitivities. We report that homologues of the aminopurine transporter TbAT1 and the aquaporin TbAQP2 are absent in T. congolense, while their introduction greatly sensitises this species to diamidine (pentamidine, diminazene) and melaminophenyl (melarsomine) drugs. Accumulation of these drugs in the transgenic lines was much more rapid. T. congolense is also inherently less sensitive to suramin than T. brucei, despite accumulating it faster. Expression of a proposed suramin transporter, located in T. brucei lysosomes, in T. congolense, did not alter its suramin sensitivity. We conclude that for several of the most important classes of trypanocides the presence of specific transporters, rather than drug targets, is the determining factor of drug efficacy.
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Natto MJ, Miyamoto Y, Munday JC, AlSiari TA, Al-Salabi MI, Quashie NB, Eze AA, Eckmann L, De Koning HP. Comprehensive characterization of purine and pyrimidine transport activities in Trichomonas vaginalis and functional cloning of a trichomonad nucleoside transporter. Mol Microbiol 2021; 116:1489-1511. [PMID: 34738285 PMCID: PMC8688338 DOI: 10.1111/mmi.14840] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 10/30/2021] [Accepted: 10/30/2021] [Indexed: 11/30/2022]
Abstract
Trichomoniasis is a common and widespread sexually-transmitted infection, caused by the protozoan parasite Trichomonas vaginalis. T. vaginalis lacks the biosynthetic pathways for purines and pyrimidines, making nucleoside metabolism a drug target. Here we report the first comprehensive investigation into purine and pyrimidine uptake by T. vaginalis. Multiple carriers were identified and characterized with regard to substrate selectivity and affinity. For nucleobases, a high-affinity adenine transporter, a possible guanine transporter and a low affinity uracil transporter were found. Nucleoside transporters included two high affinity adenosine/guanosine/uridine/cytidine transporters distinguished by different affinities to inosine, a lower affinity adenosine transporter, and a thymidine transporter. Nine Equilibrative Nucleoside Transporter (ENT) genes were identified in the T. vaginalis genome. All were expressed equally in metronidazole-resistant and -sensitive strains. Only TvagENT2 was significantly upregulated in the presence of extracellular purines; expression was not affected by co-culture with human cervical epithelial cells. All TvagENTs were cloned and separately expressed in Trypanosoma brucei. We identified the main broad specificity nucleoside carrier, with high affinity for uridine and cytidine as well as purine nucleosides including inosine, as TvagENT3. The in-depth characterization of purine and pyrimidine transporters provides a critical foundation for the development of new anti-trichomonal nucleoside analogues.
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Affiliation(s)
- Manal J. Natto
- Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Yukiko Miyamoto
- Department of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | - Jane C. Munday
- Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Tahani A. AlSiari
- Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Mohammed I. Al-Salabi
- Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Neils B. Quashie
- Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- Centre for Tropical Clinical Pharmacology and Therapeutics, University of Ghana Medical School, University of Ghana
| | - Anthonius A. Eze
- Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- Current affiliation: Department of Medical Biochemistry, Faculty of Basic Medical Sciences, College of Medicine, University of Nigeria, Enugu Campus, Enugu, Nigeria
| | - Lars Eckmann
- Department of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | - Harry P. De Koning
- Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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Carruthers LV, Munday JC, Ebiloma GU, Steketee P, Jayaraman S, Campagnaro GD, Ungogo MA, Lemgruber L, Donachie AM, Rowan TG, Peter R, Morrison LJ, Barrett MP, De Koning HP. Diminazene resistance in Trypanosoma congolense is not caused by reduced transport capacity but associated with reduced mitochondrial membrane potential. Mol Microbiol 2021; 116:564-588. [PMID: 33932053 DOI: 10.1111/mmi.14733] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 04/14/2021] [Accepted: 04/27/2021] [Indexed: 01/27/2023]
Abstract
Trypanosoma congolense is a principal agent causing livestock trypanosomiasis in Africa, costing developing economies billions of dollars and undermining food security. Only the diamidine diminazene and the phenanthridine isometamidium are regularly used, and resistance is widespread but poorly understood. We induced stable diminazene resistance in T. congolense strain IL3000 in vitro. There was no cross-resistance with the phenanthridine drugs, melaminophenyl arsenicals, oxaborole trypanocides, or with diamidine trypanocides, except the close analogs DB829 and DB75. Fluorescence microscopy showed that accumulation of DB75 was inhibited by folate. Uptake of [3 H]-diminazene was slow with low affinity and partly but reciprocally inhibited by folate and by competing diamidines. Expression of T. congolense folate transporters in diminazene-resistant Trypanosoma brucei brucei significantly sensitized the cells to diminazene and DB829, but not to oxaborole AN7973. However, [3 H]-diminazene transport studies, whole-genome sequencing, and RNA-seq found no major changes in diminazene uptake, folate transporter sequence, or expression. Instead, all resistant clones displayed a moderate reduction in the mitochondrial membrane potential Ψm. We conclude that diminazene uptake in T. congolense proceed via multiple low affinity mechanisms including folate transporters; while resistance is associated with a reduction in Ψm it is unclear whether this is the primary cause of the resistance.
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Affiliation(s)
- Lauren V Carruthers
- Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Jane C Munday
- Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Godwin U Ebiloma
- Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.,School of Health and Life Sciences, Teesside University, Middlesbrough, UK
| | - Pieter Steketee
- Roslin Institute, Royal (Dick) School of Veterinary Sciences, University of Edinburgh, Edinburgh, UK
| | - Siddharth Jayaraman
- Roslin Institute, Royal (Dick) School of Veterinary Sciences, University of Edinburgh, Edinburgh, UK
| | - Gustavo D Campagnaro
- Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Marzuq A Ungogo
- Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Leandro Lemgruber
- Glasgow Imaging Facility, Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Anne-Marie Donachie
- Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Tim G Rowan
- Global Alliance for Livestock Veterinary Medicine, Pentlands Science Park, Edinburgh, UK
| | - Rose Peter
- Global Alliance for Livestock Veterinary Medicine, Pentlands Science Park, Edinburgh, UK
| | - Liam J Morrison
- Roslin Institute, Royal (Dick) School of Veterinary Sciences, University of Edinburgh, Edinburgh, UK
| | - Michael P Barrett
- Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.,Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Harry P De Koning
- Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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11
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Hulpia F, Campagnaro GD, Alzahrani KJ, Alfayez IA, Ungogo MA, Mabille D, Maes L, de Koning HP, Caljon G, Van Calenbergh S. Structure-Activity Relationship Exploration of 3'-Deoxy-7-deazapurine Nucleoside Analogues as Anti- Trypanosoma brucei Agents. ACS Infect Dis 2020; 6:2045-2056. [PMID: 32568511 DOI: 10.1021/acsinfecdis.0c00105] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Human African trypanosomiasis is a neglected tropical disease caused by Trypanosoma brucei parasites. These protists are unable to produce the purine ring, making them vulnerable to the effects of purine nucleoside analogues. Starting from 3'-deoxytubercidin (5), a lead compound with activity against central-nervous-stage human African trypanosomiasis, we investigate the structure-activity relationships of the purine and ribofuranose rings. The purine ring tolerated only modifications at C7, while from the many alterations of the 3'-deoxyribofuranosyl moiety only the arabino analogue 48 showed pronounced antitrypanosomal activity. Profiling of the most potent analogues against resistant T. brucei strains (resistant to pentamidine, diminazene, and isometamidium) showed reduced dependence on uptake mediated by the P2 aminopurine transporter relative to 5. The introduction of a 7-substituent confers up to 10-fold increased affinity for the P1 nucleoside transporter while generally retaining high affinity for P2. Four of the most promising analogues were found to be metabolically stable, earmarking them as suitable backup analogues for lead 5.
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Affiliation(s)
- Fabian Hulpia
- Laboratory for Medicinal Chemistry (Campus Heymans), Ghent University, Ottergemsesteenweg 460, B-9000 Gent, Belgium
| | - Gustavo D. Campagnaro
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, United Kingdom
| | - Khalid J. Alzahrani
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, United Kingdom
- Department of Clinical Laboratory, College of Applied Medical Sciences, Taif University, Taif 21974, Saudi Arabia
| | - Ibrahim A. Alfayez
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, United Kingdom
| | - Marzuq A. Ungogo
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, United Kingdom
- Department of Veterinary Pharmacology and Toxicology, Ahmadu Bello University, 810211 Zaria, Kaduna State, Nigeria
| | - Dorien Mabille
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Universiteitsplein 1 (S7), B-2610 Wilrijk, Belgium
| | - Louis Maes
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Universiteitsplein 1 (S7), B-2610 Wilrijk, Belgium
| | - Harry P. de Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, United Kingdom
| | - Guy Caljon
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Universiteitsplein 1 (S7), B-2610 Wilrijk, Belgium
| | - Serge Van Calenbergh
- Laboratory for Medicinal Chemistry (Campus Heymans), Ghent University, Ottergemsesteenweg 460, B-9000 Gent, Belgium
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12
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Alghamdi AH, Munday JC, Campagnaro GD, Gurvic D, Svensson F, Okpara CE, Kumar A, Quintana J, Martin Abril ME, Milić P, Watson L, Paape D, Settimo L, Dimitriou A, Wielinska J, Smart G, Anderson LF, Woodley CM, Kelly SPY, Ibrahim HM, Hulpia F, Al-Salabi MI, Eze AA, Sprenger T, Teka IA, Gudin S, Weyand S, Field M, Dardonville C, Tidwell RR, Carrington M, O'Neill P, Boykin DW, Zachariae U, De Koning HP. Positively selected modifications in the pore of TbAQP2 allow pentamidine to enter Trypanosoma brucei. eLife 2020; 9:56416. [PMID: 32762841 PMCID: PMC7473772 DOI: 10.7554/elife.56416] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 08/06/2020] [Indexed: 11/25/2022] Open
Abstract
Mutations in the Trypanosoma brucei aquaporin AQP2 are associated with resistance to pentamidine and melarsoprol. We show that TbAQP2 but not TbAQP3 was positively selected for increased pore size from a common ancestor aquaporin. We demonstrate that TbAQP2’s unique architecture permits pentamidine permeation through its central pore and show how specific mutations in highly conserved motifs affect drug permeation. Introduction of key TbAQP2 amino acids into TbAQP3 renders the latter permeable to pentamidine. Molecular dynamics demonstrates that permeation by dicationic pentamidine is energetically favourable in TbAQP2, driven by the membrane potential, although aquaporins are normally strictly impermeable for ionic species. We also identify the structural determinants that make pentamidine a permeant although most other diamidine drugs are excluded. Our results have wide-ranging implications for optimising antitrypanosomal drugs and averting cross-resistance. Moreover, these new insights in aquaporin permeation may allow the pharmacological exploitation of other members of this ubiquitous gene family. African sleeping sickness is a potentially deadly illness caused by the parasite Trypanosoma brucei. The disease is treatable, but many of the current treatments are old and are becoming increasingly ineffective. For instance, resistance is growing against pentamidine, a drug used in the early stages in the disease, as well as against melarsoprol, which is deployed when the infection has progressed to the brain. Usually, cases resistant to pentamidine are also resistant to melarsoprol, but it is still unclear why, as the drugs are chemically unrelated. Studies have shown that changes in a water channel called aquaglyceroporin 2 (TbAQP2) contribute to drug resistance in African sleeping sickness; this suggests that it plays a role in allowing drugs to kill the parasite. This molecular ‘drain pipe’ extends through the surface of T. brucei, and should allow only water and a molecule called glycerol in and out of the cell. In particular, the channel should be too narrow to allow pentamidine or melarsoprol to pass through. One possibility is that, in T. brucei, the TbAQP2 channel is abnormally wide compared to other members of its family. Alternatively, pentamidine and melarsoprol may only bind to TbAQP2, and then ‘hitch a ride’ when the protein is taken into the parasite as part of the natural cycle of surface protein replacement. Alghamdi et al. aimed to tease out these hypotheses. Computer models of the structure of the protein were paired with engineered changes in the key areas of the channel to show that, in T. brucei, TbAQP2 provides a much broader gateway into the cell than observed for similar proteins. In addition, genetic analysis showed that this version of TbAQP2 has been actively selected for during the evolution process of T. brucei. This suggests that the parasite somehow benefits from this wider aquaglyceroporin variant. This is a new resistance mechanism, and it is possible that aquaglyceroporins are also larger than expected in other infectious microbes. The work by Alghamdi et al. therefore provides insight into how other germs may become resistant to drugs.
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Affiliation(s)
- Ali H Alghamdi
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Jane C Munday
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | | | - Dominik Gurvic
- Computational Biology Centre for Translational and Interdisciplinary Research, University of Dundee, Dundee, United Kingdom
| | - Fredrik Svensson
- IOTA Pharmaceuticals Ltd, St Johns Innovation Centre, Cambridge, United Kingdom
| | - Chinyere E Okpara
- Department of Chemistry, University of Liverpool, Liverpool, United Kingdom
| | - Arvind Kumar
- Chemistry Department, Georgia State University, Atlanta, United States
| | - Juan Quintana
- School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | | | - Patrik Milić
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Laura Watson
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Daniel Paape
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Luca Settimo
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Anna Dimitriou
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Joanna Wielinska
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Graeme Smart
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Laura F Anderson
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | | | - Siu Pui Ying Kelly
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Hasan Ms Ibrahim
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Fabian Hulpia
- Laboratory for Medicinal Chemistry, University of Ghent, Ghent, Belgium
| | - Mohammed I Al-Salabi
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Anthonius A Eze
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Teresa Sprenger
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Ibrahim A Teka
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Simon Gudin
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Simone Weyand
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Mark Field
- School of Life Sciences, University of Dundee, Dundee, United Kingdom.,Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic
| | | | - Richard R Tidwell
- Department of Pathology and Lab Medicine, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Paul O'Neill
- Department of Chemistry, University of Liverpool, Liverpool, United Kingdom
| | - David W Boykin
- Chemistry Department, Georgia State University, Atlanta, United States
| | - Ulrich Zachariae
- Computational Biology Centre for Translational and Interdisciplinary Research, University of Dundee, Dundee, United Kingdom
| | - Harry P De Koning
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
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13
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Campagnaro GD, de Koning HP. Purine and pyrimidine transporters of pathogenic protozoa - conduits for therapeutic agents. Med Res Rev 2020; 40:1679-1714. [PMID: 32144812 DOI: 10.1002/med.21667] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/12/2020] [Accepted: 02/18/2020] [Indexed: 02/06/2023]
Abstract
Purines and pyrimidines are essential nutrients for any cell. Most organisms are able to synthesize their own purines and pyrimidines, but this ability was lost in protozoans that adapted to parasitism, leading to a great diversification in transporter activities in these organisms, especially for the acquisition of amino acids and nucleosides from their hosts throughout their life cycles. Many of these transporters have been shown to have sufficiently different substrate affinities from mammalian transporters, making them good carriers for therapeutic agents. In this review, we summarize the knowledge obtained on purine and pyrimidine activities identified in protozoan parasites to date and discuss their importance for the survival of these parasites and as drug carriers, as well as the perspectives of developments in the field.
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Affiliation(s)
- Gustavo D Campagnaro
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, 120 University Place, Glasgow, UK
| | - Harry P de Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, 120 University Place, Glasgow, UK
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14
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P De Koning H. The Drugs of Sleeping Sickness: Their Mechanisms of Action and Resistance, and a Brief History. Trop Med Infect Dis 2020; 5:E14. [PMID: 31963784 PMCID: PMC7157662 DOI: 10.3390/tropicalmed5010014] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 01/15/2020] [Accepted: 01/16/2020] [Indexed: 12/17/2022] Open
Abstract
With the incidence of sleeping sickness in decline and genuine progress being made towards the WHO goal of eliminating sleeping sickness as a major public health concern, this is a good moment to evaluate the drugs that 'got the job done': their development, their limitations and the resistance that the parasites developed against them. This retrospective looks back on the remarkable story of chemotherapy against trypanosomiasis, a story that goes back to the very origins and conception of chemotherapy in the first years of the 20 century and is still not finished today.
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Affiliation(s)
- Harry P De Koning
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK
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15
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Hulpia F, Bouton J, Campagnaro GD, Alfayez IA, Mabille D, Maes L, de Koning HP, Caljon G, Van Calenbergh S. C6-O-alkylated 7-deazainosine nucleoside analogues: Discovery of potent and selective anti-sleeping sickness agents. Eur J Med Chem 2020; 188:112018. [PMID: 31931339 DOI: 10.1016/j.ejmech.2019.112018] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 12/27/2019] [Accepted: 12/27/2019] [Indexed: 01/02/2023]
Abstract
African trypanosomiasis, a deadly infectious disease caused by the protozoan Trypanosoma brucei spp., is spread to new hosts by bites of infected tsetse flies. Currently approved therapies all have their specific drawbacks, prompting a search for novel therapeutic agents. T. brucei lacks the enzymes necessary to forge the purine ring from amino acid precursors, rendering them dependent on the uptake and interconversion of host purines. This dependency renders analogues of purines and corresponding nucleosides an interesting source of potential anti-T. brucei agents. In this study, we synthesized and evaluated a series of 7-substituted 7-deazainosine derivatives and found that 6-O-alkylated analogues in particular showed highly promising in vitro activity with EC50 values in the mid-nanomolar range. SAR investigation of the O-alkyl chain showed that antitrypanosomal activity increased, and also cytotoxicity, with alkyl chain length, at least in the linear alkyl chain series. However, this could be attenuated by introducing a terminal branch point, resulting in the highly potent and selective analogues, 36, 37 and 38. No resistance related to transporter-mediated uptake could be identified, earmarking several of these analogues for further in vivo follow-up studies.
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Affiliation(s)
- Fabian Hulpia
- Laboratory for Medicinal Chemistry (Campus Heymans), Ghent University, Ottergemsesteenweg 460, B-9000, Gent, Belgium
| | - Jakob Bouton
- Laboratory for Medicinal Chemistry (Campus Heymans), Ghent University, Ottergemsesteenweg 460, B-9000, Gent, Belgium
| | - Gustavo D Campagnaro
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, United Kingdom
| | - Ibrahim A Alfayez
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, United Kingdom
| | - Dorien Mabille
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Universiteitsplein 1 (S7), B-2610, Wilrijk, Belgium
| | - Louis Maes
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Universiteitsplein 1 (S7), B-2610, Wilrijk, Belgium
| | - Harry P de Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, United Kingdom
| | - Guy Caljon
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Universiteitsplein 1 (S7), B-2610, Wilrijk, Belgium
| | - Serge Van Calenbergh
- Laboratory for Medicinal Chemistry (Campus Heymans), Ghent University, Ottergemsesteenweg 460, B-9000, Gent, Belgium.
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16
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Hulpia F, Mabille D, Campagnaro GD, Schumann G, Maes L, Roditi I, Hofer A, de Koning HP, Caljon G, Van Calenbergh S. Combining tubercidin and cordycepin scaffolds results in highly active candidates to treat late-stage sleeping sickness. Nat Commun 2019; 10:5564. [PMID: 31804484 PMCID: PMC6895180 DOI: 10.1038/s41467-019-13522-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 11/13/2019] [Indexed: 12/29/2022] Open
Abstract
African trypanosomiasis is a disease caused by Trypanosoma brucei parasites with limited treatment options. Trypanosoma is unable to synthesize purines de novo and relies solely on their uptake and interconversion from the host, constituting purine nucleoside analogues a potential source of antitrypanosomal agents. Here we combine structural elements from known trypanocidal nucleoside analogues to develop a series of 3’-deoxy-7-deazaadenosine nucleosides, and investigate their effects against African trypanosomes. 3’-Deoxytubercidin is a highly potent trypanocide in vitro and displays curative activity in animal models of acute and CNS-stage disease, even at low doses and oral administration. Whole-genome RNAi screening reveals that the P2 nucleoside transporter and adenosine kinase are involved in the uptake and activation, respectively, of this analogue. This is confirmed by P1 and P2 transporter assays and nucleotide pool analysis. 3’-Deoxytubercidin is a promising lead to treat late-stage sleeping sickness. Trypanosoma brucei relies on uptake and conversion of purines from the host, which constitutes a potential drug target. Here, Hulpia et al. combine structural elements from known trypanocidal nucleoside analogues and develop a potent trypanocide with curative activity in animal models of acute and late stage sleeping sickness.
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Affiliation(s)
- Fabian Hulpia
- Laboratory for Medicinal Chemistry (Campus Heymans), Ghent University, Ottergemsesteenweg 460, 9000, Gent, Belgium
| | - Dorien Mabille
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Gustavo D Campagnaro
- College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK
| | - Gabriela Schumann
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, 3012, Bern, Switzerland
| | - Louis Maes
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Isabel Roditi
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, 3012, Bern, Switzerland
| | - Anders Hofer
- Department of Medical Biochemistry and Biophysics, Umeå University, 901 87, Umeå, Sweden
| | - Harry P de Koning
- College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK
| | - Guy Caljon
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Serge Van Calenbergh
- Laboratory for Medicinal Chemistry (Campus Heymans), Ghent University, Ottergemsesteenweg 460, 9000, Gent, Belgium.
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17
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Zhang L, Jiang Y, Pang X, Hua P, Gao X, Li Q, Li Z. Simultaneous Optimization of Ultrasound-Assisted Extraction for Flavonoids and Antioxidant Activity of Angelica keiskei Using Response Surface Methodology (RSM). Molecules 2019; 24:E3461. [PMID: 31554203 PMCID: PMC6804174 DOI: 10.3390/molecules24193461] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/06/2019] [Accepted: 09/18/2019] [Indexed: 02/02/2023] Open
Abstract
Angelica keiskei Koidzumi (A. keiskei), as a Japanese edible herbal plant, enjoys a variety of biological activities due to the presence of numerous active compounds, especially flavonoids. This study aims for the optimization of ultrasound-assisted extraction (UAE) for flavonoids in A. keiskei and their antioxidant activity by using the response surface methodology (RSM). Single-factor experiments and a four-factor three-level Box-Behnken design (BBD) were performed to explore the effects of the following parameters on flavonoid extraction and antioxidant activity evaluation: ultrasonic temperature (X1), ultrasonic time (X2), ethanol concentration (X3) and liquid-solid ratio (X4). The optimum conditions of the combination of total flavonoid content (TFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity (DPPH-RSC) and ferric-reducing antioxidant power (FRAP) were as follows: X1 = 80 °C, X2 = 4 min, X3 = 78%, X4 = 35 mL/g, respectively. The experimental results provide a theoretical basis for the extensive utilization of A. keiskei and flavonoids extraction from A. keiskei as a potential source of antioxidants.
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Affiliation(s)
- Lei Zhang
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, China.
- Institute of Angelica keiskei Health Industry Technology, Qingdao University, Qingdao 266071, China.
| | - Yuhuan Jiang
- Institute of Angelica keiskei Health Industry Technology, Qingdao University, Qingdao 266071, China.
- Institute of Advanced Cross-Field Science, College of Life Sciences, Qingdao University, Qingdao 266071, China.
| | - Xuening Pang
- Institute of Angelica keiskei Health Industry Technology, Qingdao University, Qingdao 266071, China.
- Institute of Advanced Cross-Field Science, College of Life Sciences, Qingdao University, Qingdao 266071, China.
| | - Puyue Hua
- Institute of Angelica keiskei Health Industry Technology, Qingdao University, Qingdao 266071, China.
- Institute of Advanced Cross-Field Science, College of Life Sciences, Qingdao University, Qingdao 266071, China.
| | - Xiang Gao
- Institute of Angelica keiskei Health Industry Technology, Qingdao University, Qingdao 266071, China.
- Institute of Advanced Cross-Field Science, College of Life Sciences, Qingdao University, Qingdao 266071, China.
| | - Qun Li
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, China.
- Institute of Angelica keiskei Health Industry Technology, Qingdao University, Qingdao 266071, China.
| | - Zichao Li
- Institute of Angelica keiskei Health Industry Technology, Qingdao University, Qingdao 266071, China.
- Institute of Advanced Cross-Field Science, College of Life Sciences, Qingdao University, Qingdao 266071, China.
- Qingdao Balanson Biotech Co., Ltd., Qingdao 266071, China.
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18
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Khandazhinskaya AL, Matyugina ES, Solyev PN, Wilkinson M, Buckheit KW, Buckheit RW, Chernousova LN, Smirnova TG, Andreevskaya SN, Alzahrani KJ, Natto MJ, Kochetkov SN, de Koning HP, Seley-Radtke KL. Investigation of 5'-Norcarbocyclic Nucleoside Analogues as Antiprotozoal and Antibacterial Agents. Molecules 2019; 24:E3433. [PMID: 31546633 PMCID: PMC6804079 DOI: 10.3390/molecules24193433] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 09/16/2019] [Accepted: 09/19/2019] [Indexed: 11/17/2022] Open
Abstract
Carbocyclic nucleosides have long played a role in antiviral, antiparasitic, and antibacterial therapies. Recent results from our laboratories from two structurally related scaffolds have shown promising activity against both Mycobacterium tuberculosis and several parasitic strains. As a result, a small structure activity relationship study was designed to further probe their activity and potential. Their synthesis and the results of the subsequent biological activity are reported herein.
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Affiliation(s)
- Anastasia L. Khandazhinskaya
- Engelhardt Institute of Molecular Biology of the Russian Academy of Sciences, 32 Vavilov St., Moscow 119991, Russia; (E.S.M.); (P.N.S.); (S.N.K.)
| | - Elena S. Matyugina
- Engelhardt Institute of Molecular Biology of the Russian Academy of Sciences, 32 Vavilov St., Moscow 119991, Russia; (E.S.M.); (P.N.S.); (S.N.K.)
| | - Pavel N. Solyev
- Engelhardt Institute of Molecular Biology of the Russian Academy of Sciences, 32 Vavilov St., Moscow 119991, Russia; (E.S.M.); (P.N.S.); (S.N.K.)
| | - Maggie Wilkinson
- ImQuest BioSciences, 7340 Executive Way Suite R, Frederick, MD 21704, USA; (M.W.); (K.W.B.)
| | - Karen W. Buckheit
- ImQuest BioSciences, 7340 Executive Way Suite R, Frederick, MD 21704, USA; (M.W.); (K.W.B.)
| | - Robert W. Buckheit
- ImQuest BioSciences, 7340 Executive Way Suite R, Frederick, MD 21704, USA; (M.W.); (K.W.B.)
| | - Larisa N. Chernousova
- Central Tuberculosis Research Institute, 2 Yauzskaya Alley, Moscow 107564, Russia; (L.N.C.); (T.G.S.); (S.N.A.)
| | - Tatiana G. Smirnova
- Central Tuberculosis Research Institute, 2 Yauzskaya Alley, Moscow 107564, Russia; (L.N.C.); (T.G.S.); (S.N.A.)
| | - Sofya N. Andreevskaya
- Central Tuberculosis Research Institute, 2 Yauzskaya Alley, Moscow 107564, Russia; (L.N.C.); (T.G.S.); (S.N.A.)
| | - Khalid J. Alzahrani
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, UK; (K.J.A.); (M.J.N.); (H.P.d.K.)
- Department of Clinical Laboratory, College of Applied Medical Sciences, Taif University, Taif 21974, Saudi Arabia
| | - Manal J. Natto
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, UK; (K.J.A.); (M.J.N.); (H.P.d.K.)
| | - Sergey N. Kochetkov
- Engelhardt Institute of Molecular Biology of the Russian Academy of Sciences, 32 Vavilov St., Moscow 119991, Russia; (E.S.M.); (P.N.S.); (S.N.K.)
| | - Harry P. de Koning
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, UK; (K.J.A.); (M.J.N.); (H.P.d.K.)
| | - Katherine L. Seley-Radtke
- Department of Chemistry & Biochemistry, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
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Terán D, Doleželová E, Keough DT, Hocková D, Zíková A, Guddat LW. Crystal structures of Trypanosoma brucei hypoxanthine - guanine - xanthine phosphoribosyltransferase in complex with IMP, GMP and XMP. FEBS J 2019; 286:4721-4736. [PMID: 31287615 DOI: 10.1111/febs.14987] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 04/16/2019] [Accepted: 07/06/2019] [Indexed: 11/27/2022]
Abstract
The 6-oxopurine phosphoribosyltransferases (PRTs) are drug targets for the treatment of parasitic diseases. This is due to the fact that parasites are auxotrophic for the 6-oxopurine bases relying on salvage enzymes for the synthesis of their 6-oxopurine nucleoside monophosphates. In Trypanosoma brucei, the parasite that is the aetiological agent for sleeping sickness, there are three 6-oxopurine PRT isoforms. Two are specific for hypoxanthine and guanine, whilst the third, characterized here, uses all three naturally occurring bases with similar efficiency. Here, we have determined crystal structures for TbrHGXPRT in complex with GMP, XMP and IMP to investigate the structural basis for substrate specificity. The results show that Y201 and E208, not commonly observed within the purine binding pocket of 6-oxopurine PRTs, contribute to the versatility of this enzyme. The structures further show that a nearby water can act as an adaptor to facilitate the binding of XMP and GMP. When GMP binds, a water can accept a proton from the 2-amino group but when XMP binds, the equivalent water can donate its proton to the 2-oxo group. However, when IMP is bound, no water molecule is observed at that location. DATABASE: Coordinates and structure factors were submitted to the Protein Data Bank and have accession codes of 6MXB, 6MXC, 6MXD and 6MXG for the TbrHGXPRT.XMP complex, TbrHGXPRT.GMP complex, TbrHGXPRT.IMP complex, and TbrHGPRT.XMP complex, respectively.
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Affiliation(s)
- David Terán
- The School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Eva Doleželová
- Biology Centre CAS, Institute of Parasitology, České Budějovice, Czech Republic.,Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Dianne T Keough
- The School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Dana Hocková
- The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 6, Czech Republic
| | - Alena Zíková
- Biology Centre CAS, Institute of Parasitology, České Budějovice, Czech Republic.,Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Luke W Guddat
- The School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
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20
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Chatanga E, Mosssad E, Abdo Abubaker H, Amin Alnour S, Katakura K, Nakao R, Salim B. Evidence of multiple point mutations in Theileria annulata cytochrome b gene incriminated in buparvaquone treatment failure. Acta Trop 2019; 191:128-132. [PMID: 30599177 DOI: 10.1016/j.actatropica.2018.12.041] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 12/28/2018] [Accepted: 12/28/2018] [Indexed: 10/27/2022]
Abstract
Drug resistance is one of the emerging and re-emerging epidemics affecting both veterinary and public health sectors. Buparvaquone provides the most satisfactory means in the treatment of bovine tropical theileriosis. However, recently there has been widespread reports of development of resistance of Theileria annulata to buparvaquone. To investigate the situation in Sudan where bovine tropical theileriosis is endemic, fifty blood samples from T. annulata-positive cattle. were used for DNA extraction, PCR and cytochrome b gene nucleotide sequencing. Analysis of the two buparvaquone binding site regions Q01 (130-148) and Q02 (244-266), revealed three non- synonymous mutations at codon 146; alanine (GCT) to threonine (ACT) within the Q01 region across all 50 isolates and the other mutation at codon 129; serine (AGC) to glycine (GGC) in 18 isolates which is very close to the Q01 binding site. However, we documented another mutation at position 227; valine (GTG) to methionine (ATG) close to the close to the Q02 binding site, in three isolates with mutation at codon 129. We concluded that this study has provided evidence of point mutations in the cytochrome b gene of T. annulata that might be associated with buparvaquone treatment failure in Sudan.
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21
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Revisiting tubercidin against kinetoplastid parasites: Aromatic substitutions at position 7 improve activity and reduce toxicity. Eur J Med Chem 2019; 164:689-705. [DOI: 10.1016/j.ejmech.2018.12.050] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 11/09/2018] [Accepted: 12/20/2018] [Indexed: 02/05/2023]
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22
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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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23
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Nnadi CO, Ebiloma GU, Black JA, Nwodo NJ, Lemgruber L, Schmidt TJ, de Koning HP. Potent Antitrypanosomal Activities of 3-Aminosteroids against African Trypanosomes: Investigation of Cellular Effects and of Cross-Resistance with Existing Drugs. Molecules 2019; 24:E268. [PMID: 30642032 PMCID: PMC6359104 DOI: 10.3390/molecules24020268] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 01/07/2019] [Accepted: 01/08/2019] [Indexed: 11/16/2022] Open
Abstract
Treatment of animal African trypanosomiasis (AAT) requires urgent need for safe, potent and affordable drugs and this has necessitated this study. We investigated the trypanocidal activities and mode of action of selected 3-aminosteroids against Trypanosoma brucei brucei. The in vitro activity of selected compounds of this series against T. congolense (Savannah-type, IL3000), T. b. brucei (bloodstream trypomastigote, Lister strain 427 wild-type (427WT)) and various multi-drug resistant cell lines was assessed using a resazurin-based cell viability assay. Studies on mode of antitrypanosomal activity of some selected 3-aminosteroids against Tbb 427WT were also carried out. The tested compounds mostly showed moderate-to-low in vitro activities and low selectivity to mammalian cells. Interestingly, a certain aminosteroid, holarrhetine (10, IC50 = 0.045 ± 0.03 µM), was 2 times more potent against T. congolense than the standard veterinary drug, diminazene aceturate, and 10 times more potent than the control trypanocide, pentamidine, and displayed an excellent in vitro selectivity index of 2130 over L6 myoblasts. All multi-drug resistant strains of T. b. brucei tested were not significantly cross-resistant with the purified compounds. The growth pattern of Tbb 427WT on long and limited exposure time revealed gradual but irrecoverable growth arrest at ≥ IC50 concentrations of 3-aminosteroids. Trypanocidal action was not associated with membrane permeabilization of trypanosome cells but instead with mitochondrial membrane depolarization, reduced adenosine triphosphate (ATP) levels and G₂/M cell cycle arrest which appear to be the result of mitochondrial accumulation of the aminosteroids. These findings provided insights for further development of this new and promising class of trypanocide against African trypanosomes.
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Affiliation(s)
- Charles O Nnadi
- Institute of Pharmaceutical Biology and Phytochemistry (IPBP), University of Münster, Pharma Campus Corrensstraße 48, D-48149 Münster, Germany.
- Department of Pharmaceutical and Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Nigeria Nsukka, Enugu 410001, Nigeria.
| | - Godwin U Ebiloma
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK.
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto 606-8585, Japan.
| | - Jennifer A Black
- The Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK.
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14049-900, Brazil.
| | - Ngozi J Nwodo
- Department of Pharmaceutical and Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Nigeria Nsukka, Enugu 410001, Nigeria.
| | - Leandro Lemgruber
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK.
| | - Thomas J Schmidt
- Institute of Pharmaceutical Biology and Phytochemistry (IPBP), University of Münster, Pharma Campus Corrensstraße 48, D-48149 Münster, Germany.
| | - Harry P de Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK.
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Landfear SM. Protean permeases: Diverse roles for membrane transport proteins in kinetoplastid protozoa. Mol Biochem Parasitol 2018; 227:39-46. [PMID: 30590069 DOI: 10.1016/j.molbiopara.2018.12.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 12/13/2018] [Accepted: 12/19/2018] [Indexed: 11/26/2022]
Abstract
Kinetoplastid parasites such as Trypanosoma brucei, Trypanosoma cruzi, and Leishmania species rely upon their insect and vertebrate hosts to provide a plethora of nutrients throughout their life cycles. Nutrients and ions critical for parasite survival are taken up across the parasite plasma membrane by transporters and channels, polytopic membrane proteins that provide substrate-specific pores across the hydrophobic barrier. However, transporters and channels serve a wide range of biological functions beyond uptake of nutrients. This article highlights the diversity of activities that these integral membrane proteins serve and underscores the emerging complexity of their functions.
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Affiliation(s)
- Scott M Landfear
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, 97239, USA.
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25
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Campagnaro GD, de Freitas Nascimento J, Girard RB, Silber AM, de Koning HP. Cloning and characterisation of the Equilibrative Nucleoside Transporter family of Trypanosoma cruzi: ultra-high affinity and selectivity to survive in the intracellular niche. Biochim Biophys Acta Gen Subj 2018; 1862:2750-2763. [DOI: 10.1016/j.bbagen.2018.08.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 08/22/2018] [Accepted: 08/23/2018] [Indexed: 12/27/2022]
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26
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Melarsoprol Resistance in African Trypanosomiasis. Trends Parasitol 2018; 34:481-492. [DOI: 10.1016/j.pt.2018.04.002] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/03/2018] [Accepted: 04/04/2018] [Indexed: 01/06/2023]
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27
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Campagnaro GD, Alzahrani KJ, Munday JC, De Koning HP. Trypanosoma brucei bloodstream forms express highly specific and separate transporters for adenine and hypoxanthine; evidence for a new protozoan purine transporter family? Mol Biochem Parasitol 2018; 220:46-56. [DOI: 10.1016/j.molbiopara.2018.01.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 01/10/2018] [Accepted: 01/19/2018] [Indexed: 10/18/2022]
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28
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Drug resistance in protozoan parasites. Emerg Top Life Sci 2017; 1:627-632. [PMID: 33525852 PMCID: PMC7289004 DOI: 10.1042/etls20170113] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 11/04/2017] [Accepted: 11/10/2017] [Indexed: 01/08/2023]
Abstract
As with all other anti-infectives (antibiotics, anti-viral drugs, and anthelminthics), the limited arsenal of anti-protozoal drugs is being depleted by a combination of two factors: increasing drug resistance and the failure to replace old and often shamefully inadequate drugs, including those compromised by (cross)-resistance, through the development of new anti-parasitics. Both factors are equally to blame: a leaking bathtub may have plenty of water if the tap is left open; if not, it will soon be empty. Here, I will reflect on the factors that contribute to the drug resistance emergency that is unfolding around us, specifically resistance in protozoan parasites.
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29
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Alzahrani KJH, Ali JAM, Eze AA, Looi WL, Tagoe DNA, Creek DJ, Barrett MP, de Koning HP. Functional and genetic evidence that nucleoside transport is highly conserved in Leishmania species: Implications for pyrimidine-based chemotherapy. Int J Parasitol Drugs Drug Resist 2017; 7:206-226. [PMID: 28453984 PMCID: PMC5407577 DOI: 10.1016/j.ijpddr.2017.04.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 04/14/2017] [Accepted: 04/18/2017] [Indexed: 11/28/2022]
Abstract
Leishmania pyrimidine salvage is replete with opportunities for therapeutic intervention with enzyme inhibitors or antimetabolites. Their uptake into cells depends upon specific transporters; therefore it is essential to establish whether various Leishmania species possess similar pyrimidine transporters capable of drug uptake. Here, we report a comprehensive characterization of pyrimidine transport in L. major and L. mexicana. In both species, two transporters for uridine/adenosine were detected, one of which also transported uracil and the antimetabolites 5-fluoruracil (5-FU) and 5F,2'deoxyuridine (5F,2'dUrd), and was designated uridine-uracil transporter 1 (UUT1); the other transporter mediated uptake of adenosine, uridine, 5F,2'dUrd and thymidine and was designated Nucleoside Transporter 1 (NT1). To verify the reported L. donovani model of two NT1-like genes encoding uridine/adenosine transporters, and an NT2 gene encoding an inosine transporter, we cloned the corresponding L. major and L. mexicana genes, expressing each in T. brucei. Consistent with the L. donovani reports, the NT1-like genes of either species mediated the adenosine-sensitive uptake of [3H]-uridine but not of [3H]-inosine. Conversely, the NT2-like genes mediated uptake of [3H]-inosine but not [3H]-uridine. Among pyrimidine antimetabolites tested, 5-FU and 5F,2'dUrd were the most effective antileishmanials; resistance to both analogs was induced in L. major and L. mexicana. In each case it was found that the resistant cells had lost the transport capacity for the inducing drug. Metabolomics analysis found that the mechanism of action of 5-FU and 5F-2'dUrd was similar in both Leishmania species, with major changes in deoxynucleotide metabolism. We conclude that the pyrimidine salvage system is highly conserved in Leishmania species - essential information for the development of pyrimidine-based chemotherapy.
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Affiliation(s)
- Khalid J H Alzahrani
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom; Department of Clinical Laboratory, College of Applied Medical Sciences, Taif University, Taif, Saudi Arabia
| | - Juma A M Ali
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom; Al Jabal Al Gharbi University, Gharyan, Libya
| | - Anthonius A Eze
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom; Department of Medical Biochemistry, College of Medicine, University of Nigeria, Enugu Campus, Enugu, Nigeria
| | - Wan Limm Looi
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Daniel N A Tagoe
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom; Wellcome Trust Centre for Molecular Parasitology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Darren J Creek
- Department of Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Michael P Barrett
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom; Wellcome Trust Centre for Molecular Parasitology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Harry P de Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom.
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30
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Evaluation of the antiprotozoan properties of 5′-norcarbocyclic pyrimidine nucleosides. Bioorg Med Chem Lett 2017; 27:3081-3086. [DOI: 10.1016/j.bmcl.2017.05.052] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 05/15/2017] [Accepted: 05/16/2017] [Indexed: 12/11/2022]
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31
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9-(2'-Deoxy-2'-Fluoro-β-d-Arabinofuranosyl) Adenine Is a Potent Antitrypanosomal Adenosine Analogue That Circumvents Transport-Related Drug Resistance. Antimicrob Agents Chemother 2017; 61:AAC.02719-16. [PMID: 28373184 PMCID: PMC5444181 DOI: 10.1128/aac.02719-16] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 03/27/2017] [Indexed: 01/25/2023] Open
Abstract
Current chemotherapy against African sleeping sickness, a disease caused by the protozoan parasite Trypanosoma brucei, is limited by toxicity, inefficacy, and drug resistance. Nucleoside analogues have been successfully used to cure T. brucei-infected mice, but they have the limitation of mainly being taken up by the P2 nucleoside transporter, which, when mutated, is a common cause of multidrug resistance in T. brucei We report here that adenine arabinoside (Ara-A) and the newly tested drug 9-(2'-deoxy-2'-fluoro-β-d-arabinofuranosyl) adenine (FANA-A) are instead taken up by the P1 nucleoside transporter, which is not associated with drug resistance. Like Ara-A, FANA-A was found to be resistant to cleavage by methylthioadenosine phosphorylase, an enzyme that protects T. brucei against the antitrypanosomal effects of deoxyadenosine. Another important factor behind the selectivity of nucleoside analogues is how well they are phosphorylated within the cell. We found that the T. brucei adenosine kinase had a higher catalytic efficiency with FANA-A than the mammalian enzyme, and T. brucei cells treated with FANA-A accumulated high levels of FANA-A triphosphate, which even surpassed the level of ATP and led to cell cycle arrest, inhibition of DNA synthesis, and the accumulation of DNA breaks. FANA-A inhibited nucleic acid biosynthesis and parasite proliferation with 50% effective concentrations (EC50s) in the low nanomolar range, whereas mammalian cell proliferation was inhibited in the micromolar range. Both Ara-A and FANA-A, in combination with deoxycoformycin, cured T. brucei-infected mice, but FANA-A did so at a dose 100 times lower than that of Ara-A.
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Sekhar GN, Georgian AR, Sanderson L, Vizcay-Barrena G, Brown RC, Muresan P, Fleck RA, Thomas SA. Organic cation transporter 1 (OCT1) is involved in pentamidine transport at the human and mouse blood-brain barrier (BBB). PLoS One 2017; 12:e0173474. [PMID: 28362799 PMCID: PMC5376088 DOI: 10.1371/journal.pone.0173474] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 02/21/2017] [Indexed: 02/02/2023] Open
Abstract
Pentamidine is an effective trypanocidal drug used against stage 1 Human African Trypanosomiasis (HAT). At the blood-brain barrier (BBB), it accumulates inside the endothelial cells but has limited entry into the brain. This study examined transporters involved in pentamidine transport at the human and mouse BBB using hCMEC/D3 and bEnd.3 cell lines, respectively. Results revealed that both cell lines expressed the organic cation transporters (OCT1, OCT2 and OCT3), however, P-gp was only expressed in hCMEC/D3 cells. Polarised expression of OCT1 was also observed. Functional assays found that ATP depletion significantly increased [3H]pentamidine accumulation in hCMEC/D3 cells (***p<0.001) but not in bEnd.3 cells. Incubation with unlabelled pentamidine significantly decreased accumulation in hCMEC/D3 and bEnd.3 cells after 120 minutes (***p<0.001). Treating both cell lines with haloperidol and amantadine also decreased [3H]pentamidine accumulation significantly (***p<0.001 and **p<0.01 respectively). However, prazosin treatment decreased [3H]pentamidine accumulation only in hCMEC/D3 cells (*p<0.05), and not bEnd.3 cells. Furthermore, the presence of OCTN, MATE, PMAT, ENT or CNT inhibitors/substrates had no significant effect on the accumulation of [3H]pentamidine in both cell lines. From the data, we conclude that pentamidine interacts with multiple transporters, is taken into brain endothelial cells by OCT1 transporter and is extruded into the blood by ATP-dependent mechanisms. These interactions along with the predominant presence of OCT1 in the luminal membrane of the BBB contribute to the limited entry of pentamidine into the brain. This information is of key importance to the development of pentamidine based combination therapies which could be used to treat CNS stage HAT by improving CNS delivery, efficacy against trypanosomes and safety profile of pentamidine.
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Affiliation(s)
- Gayathri N. Sekhar
- King’s College London, Institute of Pharmaceutical Science, Waterloo, London United Kingdom
| | - Ana R. Georgian
- King’s College London, Institute of Pharmaceutical Science, Waterloo, London United Kingdom
| | - Lisa Sanderson
- King’s College London, Institute of Pharmaceutical Science, Waterloo, London United Kingdom
| | - Gema Vizcay-Barrena
- King’s College London, Centre for Ultrastructural Imaging, King’s College London, London Bridge United Kingdom
| | - Rachel C. Brown
- King’s College London, Institute of Pharmaceutical Science, Waterloo, London United Kingdom
| | - Paula Muresan
- King’s College London, Institute of Pharmaceutical Science, Waterloo, London United Kingdom
| | - Roland A. Fleck
- King’s College London, Centre for Ultrastructural Imaging, King’s College London, London Bridge United Kingdom
| | - Sarah A. Thomas
- King’s College London, Institute of Pharmaceutical Science, Waterloo, London United Kingdom
- * E-mail:
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Abstract
Pathogenic animal trypanosomes affecting livestock have represented a major constraint to agricultural development in Africa for centuries, and their negative economic impact is increasing in South America and Asia. Chemotherapy and chemoprophylaxis represent the main means of control. However, research into new trypanocides has remained inadequate for decades, leading to a situation where the few compounds available are losing efficacy due to the emergence of drug-resistant parasites. In this review, we provide a comprehensive overview of the current options available for the treatment and prophylaxis of the animal trypanosomiases, with a special focus on the problem of resistance. The key issues surrounding the main economically important animal trypanosome species and the diseases they cause are also presented. As new investment becomes available to develop improved tools to control the animal trypanosomiases, we stress that efforts should be directed towards a better understanding of the biology of the relevant parasite species and strains, to identify new drug targets and interrogate resistance mechanisms.
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Zoltner M, Horn D, de Koning HP, Field MC. Exploiting the Achilles' heel of membrane trafficking in trypanosomes. Curr Opin Microbiol 2016; 34:97-103. [PMID: 27614711 PMCID: PMC5176092 DOI: 10.1016/j.mib.2016.08.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 08/16/2016] [Accepted: 08/24/2016] [Indexed: 11/25/2022]
Abstract
Pathogenic protozoa are evolutionarily highly divergent from their metazoan hosts, reflected in many aspects of their biology. One particularly important parasite taxon is the trypanosomatids. Multiple transmission modes, distinct life cycles and exploitation of many host species attests to great prowess as parasites, and adaptability for efficient, chronic infection. Genome sequencing has begun uncovering how trypanosomatids are well suited to parasitism, and recent genetic screening and cell biology are revealing new aspects of how to control these organisms and prevent disease. Importantly, several lines of evidence suggest that membrane transport processes are central for the sensitivity towards several frontline drugs.
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Affiliation(s)
- Martin Zoltner
- School of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - David Horn
- School of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Harry P de Koning
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, Scotland, UK
| | - Mark C Field
- School of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK.
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Graf FE, Ludin P, Arquint C, Schmidt RS, Schaub N, Kunz Renggli C, Munday JC, Krezdorn J, Baker N, Horn D, Balmer O, Caccone A, de Koning HP, Mäser P. Comparative genomics of drug resistance in Trypanosoma brucei rhodesiense. Cell Mol Life Sci 2016; 73:3387-400. [PMID: 26973180 PMCID: PMC4967103 DOI: 10.1007/s00018-016-2173-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 03/01/2016] [Indexed: 12/02/2022]
Abstract
Trypanosoma brucei rhodesiense is one of the causative agents of human sleeping sickness, a fatal disease that is transmitted by tsetse flies and restricted to Sub-Saharan Africa. Here we investigate two independent lines of T. b. rhodesiense that have been selected with the drugs melarsoprol and pentamidine over the course of 2 years, until they exhibited stable cross-resistance to an unprecedented degree. We apply comparative genomics and transcriptomics to identify the underlying mutations. Only few mutations have become fixed during selection. Three genes were affected by mutations in both lines: the aminopurine transporter AT1, the aquaporin AQP2, and the RNA-binding protein UBP1. The melarsoprol-selected line carried a large deletion including the adenosine transporter gene AT1, whereas the pentamidine-selected line carried a heterozygous point mutation in AT1, G430R, which rendered the transporter non-functional. Both resistant lines had lost AQP2, and both lines carried the same point mutation, R131L, in the RNA-binding motif of UBP1. The finding that concomitant deletion of the known resistance genes AT1 and AQP2 in T. b. brucei failed to phenocopy the high levels of resistance of the T. b. rhodesiense mutants indicated a possible role of UBP1 in melarsoprol-pentamidine cross-resistance. However, homozygous in situ expression of UBP1-Leu(131) in T. b. brucei did not affect the sensitivity to melarsoprol or pentamidine.
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Affiliation(s)
- Fabrice E Graf
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland
- University of Basel, 4000, Basel, Switzerland
| | - Philipp Ludin
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland
- University of Basel, 4000, Basel, Switzerland
| | - Christian Arquint
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland
- University of Basel, 4000, Basel, Switzerland
| | - Remo S Schmidt
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland
- University of Basel, 4000, Basel, Switzerland
| | - Nadia Schaub
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland
- University of Basel, 4000, Basel, Switzerland
| | - Christina Kunz Renggli
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland
- University of Basel, 4000, Basel, Switzerland
| | - Jane C Munday
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK
| | - Jessica Krezdorn
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK
| | - Nicola Baker
- Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
- The University of Kent, Canterbury, Kent, CT2 7NZ, UK
| | - David Horn
- Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - Oliver Balmer
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland
- University of Basel, 4000, Basel, Switzerland
| | - Adalgisa Caccone
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA
| | - Harry P de Koning
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK
| | - Pascal Mäser
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland.
- University of Basel, 4000, Basel, Switzerland.
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Eze AA, Gould MK, Munday JC, Tagoe DNA, Stelmanis V, Schnaufer A, De Koning HP. Reduced Mitochondrial Membrane Potential Is a Late Adaptation of Trypanosoma brucei brucei to Isometamidium Preceded by Mutations in the γ Subunit of the F1Fo-ATPase. PLoS Negl Trop Dis 2016; 10:e0004791. [PMID: 27518185 PMCID: PMC4982688 DOI: 10.1371/journal.pntd.0004791] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 05/30/2016] [Indexed: 11/19/2022] Open
Abstract
Background Isometamidium is the main prophylactic drug used to prevent the infection of livestock with trypanosomes that cause Animal African Trypanosomiasis. As well as the animal infective trypanosome species, livestock can also harbor the closely related human infective subspecies T. b. gambiense and T. b. rhodesiense. Resistance to isometamidium is a growing concern, as is cross-resistance to the diamidine drugs diminazene and pentamidine. Methodology/Principal Findings Two isometamidium resistant Trypanosoma brucei clones were generated (ISMR1 and ISMR15), being 7270- and 16,000-fold resistant to isometamidium, respectively, which retained their ability to grow in vitro and establish an infection in mice. Considerable cross-resistance was shown to ethidium bromide and diminazene, with minor cross-resistance to pentamidine. The mitochondrial membrane potentials of both resistant cell lines were significantly reduced compared to the wild type. The net uptake rate of isometamidium was reduced 2-3-fold but isometamidium efflux was similar in wild-type and resistant lines. Fluorescence microscopy and PCR analysis revealed that ISMR1 and ISMR15 had completely lost their kinetoplast DNA (kDNA) and both lines carried a mutation in the nuclearly encoded γ subunit gene of F1 ATPase, truncating the protein by 22 amino acids. The mutation compensated for the loss of the kinetoplast in bloodstream forms, allowing near-normal growth, and conferred considerable resistance to isometamidium and ethidium as well as significant resistance to diminazene and pentamidine, when expressed in wild type trypanosomes. Subsequent exposure to either isometamidium or ethidium led to rapid loss of kDNA and a further increase in isometamidium resistance. Conclusions/Significance Sub-lethal exposure to isometamidium gives rise to viable but highly resistant trypanosomes that, depending on sub-species, are infective to humans and cross-resistant to at least some diamidine drugs. The crucial mutation is in the F1 ATPase γ subunit, which allows loss of kDNA and results in a reduction of the mitochondrial membrane potential. Isometamidium is the only prophylactic treatment of Animal African Trypanosomiasis, a wasting disease of livestock and domestic animals in sub-Saharan Africa. Unfortunately resistance threatens the continued utility of this drug after decades of use. Not only does this disease have severe impacts on agriculture, but some subspecies of Trypanosoma brucei are human-infective as well (causing sleeping sickness) and there is concern that cross-resistance with trypanocides of the diamidine class could further undermine treatment of both veterinary and human infections. It is therefore essential to understand the mechanism of isometamidium resistance and the likelihood for cross-resistance with other first-line trypanocides. Here, we report that isometamidium resistance can be caused by a mutation in an important mitochondrial protein, the γ subunit of the F1 ATPase, and that this mutation alone is sufficient for high levels of resistance, cross-resistance to various drugs, and a strongly reduced mitochondrial membrane potential. This report will for the first time enable a structural assessment of isometamidium resistance genes in T. brucei spp.
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Affiliation(s)
- Anthonius A. Eze
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Matthew K. Gould
- Institute for Immunology and Infection Research and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Jane C. Munday
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Daniel N. A. Tagoe
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, United Kingdom
| | - Valters Stelmanis
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Achim Schnaufer
- Institute for Immunology and Infection Research and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Harry P. De Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- * E-mail:
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37
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Morrison LJ, Vezza L, Rowan T, Hope JC. Animal African Trypanosomiasis: Time to Increase Focus on Clinically Relevant Parasite and Host Species. Trends Parasitol 2016; 32:599-607. [PMID: 27167665 DOI: 10.1016/j.pt.2016.04.012] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 04/19/2016] [Accepted: 04/20/2016] [Indexed: 10/21/2022]
Abstract
Animal African trypanosomiasis (AAT), caused by Trypanosoma congolense and Trypanosoma vivax, remains one of the most important livestock diseases in sub-Saharan Africa, particularly affecting cattle. Despite this, our detailed knowledge largely stems from the human pathogen Trypanosoma brucei and mouse experimental models. In the postgenomic era, the genotypic and phenotypic differences between the AAT-relevant species of parasite or host and their model organism counterparts are increasingly apparent. Here, we outline the timeliness and advantages of increasing the research focus on both the clinically relevant parasite and host species, given that improved tools and resources for both have been developed in recent years. We propose that this shift of emphasis will improve our ability to efficiently develop tools to combat AAT.
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Affiliation(s)
- Liam J Morrison
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK.
| | - Laura Vezza
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - Tim Rowan
- GALVmed, Doherty Building, Pentlands Science Park, Bush Loan, Edinburgh, EH25 0PZ, UK
| | - Jayne C Hope
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
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Birhanu H, Gebrehiwot T, Goddeeris BM, Büscher P, Van Reet N. New Trypanosoma evansi Type B Isolates from Ethiopian Dromedary Camels. PLoS Negl Trop Dis 2016; 10:e0004556. [PMID: 27035661 PMCID: PMC4818106 DOI: 10.1371/journal.pntd.0004556] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 02/27/2016] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Trypanosoma (T.) evansi is a dyskinetoplastic variant of T. brucei that has gained the ability to be transmitted by all sorts of biting flies. T. evansi can be divided into type A, which is the most abundant and found in Africa, Asia and Latin America and type B, which has so far been isolated only from Kenyan dromedary camels. This study aimed at the isolation and the genetic and phenotypic characterisation of type A and B T. evansi stocks from camels in Northern Ethiopia. METHODOLOGY/PRINCIPAL FINDINGS T. evansi was isolated in mice by inoculation with the cryopreserved buffy coat of parasitologically confirmed animals. Fourteen stocks were thus isolated and subject to genotyping with PCRs targeting type-specific variant surface glycoprotein genes, mitochondrial minicircles and maxicircles, minisatellite markers and the F1-ATP synthase γ subunit gene. Nine stocks corresponded to type A, two stocks were type B and three stocks represented mixed infections between A and B, but not hybrids. One T. evansi type A stock was completely akinetoplastic. Five stocks were adapted to in vitro culture and subjected to a drug sensitivity assay with melarsomine dihydrochloride, diminazene diaceturate, isometamidium chloride and suramin. In vitro adaptation induced some loss of kinetoplasts within 60 days. No correlation between drug sensitivity and absence of the kinetoplast was observed. Sequencing the full coding sequence of the F1-ATP synthase γ subunit revealed new type-specific single nucleotide polymorphisms and deletions. CONCLUSIONS/SIGNIFICANCE This study addresses some limitations of current molecular markers for T. evansi genotyping. Polymorphism within the F1-ATP synthase γ subunit gene may provide new markers to identify the T. evansi type that do not rely on variant surface glycoprotein genes or kinetoplast DNA.
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Affiliation(s)
- Hadush Birhanu
- College of Veterinary Medicine, Mekelle University, Mekelle, Ethiopia
- KU Leuven, Faculty of Bioscience Engineering, Department of Biosystems, Leuven, Belgium
- Institute of Tropical Medicine, Department of Biomedical Sciences, Antwerp, Belgium
- * E-mail:
| | | | - Bruno Maria Goddeeris
- KU Leuven, Faculty of Bioscience Engineering, Department of Biosystems, Leuven, Belgium
| | - Philippe Büscher
- Institute of Tropical Medicine, Department of Biomedical Sciences, Antwerp, Belgium
| | - Nick Van Reet
- Institute of Tropical Medicine, Department of Biomedical Sciences, Antwerp, Belgium
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Unciti-Broceta JD, Arias JL, Maceira J, Soriano M, Ortiz-González M, Hernández-Quero J, Muñóz-Torres M, de Koning HP, Magez S, Garcia-Salcedo JA. Specific Cell Targeting Therapy Bypasses Drug Resistance Mechanisms in African Trypanosomiasis. PLoS Pathog 2015; 11:e1004942. [PMID: 26110623 PMCID: PMC4482409 DOI: 10.1371/journal.ppat.1004942] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 05/08/2015] [Indexed: 01/01/2023] Open
Abstract
African trypanosomiasis is a deadly neglected disease caused by the extracellular parasite Trypanosoma brucei. Current therapies are characterized by high drug toxicity and increasing drug resistance mainly associated with loss-of-function mutations in the transporters involved in drug import. The introduction of new antiparasitic drugs into therapeutic use is a slow and expensive process. In contrast, specific targeting of existing drugs could represent a more rapid and cost-effective approach for neglected disease treatment, impacting through reduced systemic toxicity and circumventing resistance acquired through impaired compound uptake. We have generated nanoparticles of chitosan loaded with the trypanocidal drug pentamidine and coated by a single domain nanobody that specifically targets the surface of African trypanosomes. Once loaded into this nanocarrier, pentamidine enters trypanosomes through endocytosis instead of via classical cell surface transporters. The curative dose of pentamidine-loaded nanobody-chitosan nanoparticles was 100-fold lower than pentamidine alone in a murine model of acute African trypanosomiasis. Crucially, this new formulation displayed undiminished in vitro and in vivo activity against a trypanosome cell line resistant to pentamidine as a result of mutations in the surface transporter aquaglyceroporin 2. We conclude that this new drug delivery system increases drug efficacy and has the ability to overcome resistance to some anti-protozoal drugs.
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Affiliation(s)
- Juan D. Unciti-Broceta
- Unidad de Enfermedades Infecciosas y Microbiología, Instituto de Investigación Biosanitaria ibs.GRANADA, Hospitales Universitarios de Granada/Universidad de Granada, Granada, Spain
- Instituto de Parasitología y Biomedicina “López-Neyra” (IPBLN-CSIC), PTS Granada, Armilla, Spain
- Centro Pfizer-Universidad de Granada-Junta de Andalucía de Genómica e Investigación Oncológica (GENYO), PTS Granada, Granada, Spain
| | - José L. Arias
- Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Granada, Granada, Spain
| | - José Maceira
- Unidad de Enfermedades Infecciosas y Microbiología, Instituto de Investigación Biosanitaria ibs.GRANADA, Hospitales Universitarios de Granada/Universidad de Granada, Granada, Spain
- Instituto de Parasitología y Biomedicina “López-Neyra” (IPBLN-CSIC), PTS Granada, Armilla, Spain
- Centro Pfizer-Universidad de Granada-Junta de Andalucía de Genómica e Investigación Oncológica (GENYO), PTS Granada, Granada, Spain
| | - Miguel Soriano
- Centro Pfizer-Universidad de Granada-Junta de Andalucía de Genómica e Investigación Oncológica (GENYO), PTS Granada, Granada, Spain
- Departamento de Agronomía, Universidad de Almería, Almería, Spain
| | - Matilde Ortiz-González
- Unidad de Enfermedades Infecciosas y Microbiología, Instituto de Investigación Biosanitaria ibs.GRANADA, Hospitales Universitarios de Granada/Universidad de Granada, Granada, Spain
- Centro Pfizer-Universidad de Granada-Junta de Andalucía de Genómica e Investigación Oncológica (GENYO), PTS Granada, Granada, Spain
| | - José Hernández-Quero
- Unidad de Enfermedades Infecciosas y Microbiología, Instituto de Investigación Biosanitaria ibs.GRANADA, Hospitales Universitarios de Granada/Universidad de Granada, Granada, Spain
| | - Manuel Muñóz-Torres
- Unidad de Metabolismo Óseo, Instituto de Investigación Biosanitaria ibs.GRANADA, Hospitales Universitarios de Granada/Universidad de Granada, Granada, Spain
| | - Harry P. de Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Stefan Magez
- Unit of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Brussels, Belgium
- Department of Structural Biology, VIB, Vrije Universiteit Brussel, Brussels, Belgium
| | - José A. Garcia-Salcedo
- Unidad de Enfermedades Infecciosas y Microbiología, Instituto de Investigación Biosanitaria ibs.GRANADA, Hospitales Universitarios de Granada/Universidad de Granada, Granada, Spain
- Instituto de Parasitología y Biomedicina “López-Neyra” (IPBLN-CSIC), PTS Granada, Armilla, Spain
- Centro Pfizer-Universidad de Granada-Junta de Andalucía de Genómica e Investigación Oncológica (GENYO), PTS Granada, Granada, Spain
- * E-mail:
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