51
|
Bais S, Churgin MA, Fang-Yen C, Greenberg RM. Evidence for Novel Pharmacological Sensitivities of Transient Receptor Potential (TRP) Channels in Schistosoma mansoni. PLoS Negl Trop Dis 2015; 9:e0004295. [PMID: 26655809 PMCID: PMC4676680 DOI: 10.1371/journal.pntd.0004295] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 11/20/2015] [Indexed: 11/18/2022] Open
Abstract
Schistosomiasis, caused by parasitic flatworms of the genus Schistosoma, is a neglected tropical disease affecting hundreds of millions globally. Praziquantel (PZQ), the only drug currently available for treatment and control, is largely ineffective against juvenile worms, and reports of PZQ resistance lend added urgency to the need for development of new therapeutics. Ion channels, which underlie electrical excitability in cells, are validated targets for many current anthelmintics. Transient receptor potential (TRP) channels are a large family of non-selective cation channels. TRP channels play key roles in sensory transduction and other critical functions, yet the properties of these channels have remained essentially unexplored in parasitic helminths. TRP channels fall into several (7-8) subfamilies, including TRPA and TRPV. Though schistosomes contain genes predicted to encode representatives of most of the TRP channel subfamilies, they do not appear to have genes for any TRPV channels. Nonetheless, we find that the TRPV1-selective activators capsaicin and resiniferatoxin (RTX) induce dramatic hyperactivity in adult worms; capsaicin also increases motility in schistosomula. SB 366719, a highly-selective TRPV1 antagonist, blocks the capsaicin-induced hyperactivity in adults. Mammalian TRPA1 is not activated by capsaicin, yet knockdown of the single predicted TRPA1-like gene (SmTRPA) in S. mansoni effectively abolishes capsaicin-induced responses in adult worms, suggesting that SmTRPA is required for capsaicin sensitivity in these parasites. Based on these results, we hypothesize that some schistosome TRP channels have novel pharmacological sensitivities that can be targeted to disrupt normal parasite neuromuscular function. These results also have implications for understanding the phylogeny of metazoan TRP channels and may help identify novel targets for new or repurposed therapeutics.
Collapse
Affiliation(s)
- Swarna Bais
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Matthew A. Churgin
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Christopher Fang-Yen
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Robert M. Greenberg
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
52
|
Stroehlein AJ, Young ND, Jex AR, Sternberg PW, Tan P, Boag PR, Hofmann A, Gasser RB. Defining the Schistosoma haematobium kinome enables the prediction of essential kinases as anti-schistosome drug targets. Sci Rep 2015; 5:17759. [PMID: 26635209 PMCID: PMC4669435 DOI: 10.1038/srep17759] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 08/26/2015] [Indexed: 01/13/2023] Open
Abstract
The blood fluke Schistosoma haematobium causes urogenital schistosomiasis, a neglected tropical disease (NTD) that affects more than 110 million people. Treating this disease by targeted or mass administration with a single chemical, praziquantel, carries the risk that drug resistance will develop in this pathogen. Therefore, there is an imperative to search for new drug targets in S. haematobium and other schistosomes. In this regard, protein kinases have potential, given their essential roles in biological processes and as targets for drugs already approved by the US Food and Drug Administration (FDA) for use in humans. In this context, we defined here the kinome of S. haematobium using a refined bioinformatic pipeline. We classified, curated and annotated predicted kinases, and assessed the developmental transcription profiles of kinase genes. Then, we prioritised a panel of kinases as potential drug targets and inferred chemicals that bind to them using an integrated bioinformatic pipeline. Most kinases of S. haematobium are very similar to those of its congener, S. mansoni, offering the prospect of designing chemicals that kill both species. Overall, this study provides a global insight into the kinome of S. haematobium and should assist the repurposing or discovery of drugs against schistosomiasis.
Collapse
Affiliation(s)
- Andreas J. Stroehlein
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Neil D. Young
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Aaron R. Jex
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Paul W. Sternberg
- HHMI, Division of Biology, California Institute of Technology, Pasadena, California, USA
| | - Patrick Tan
- Genome Institute of Singapore, Republic of Singapore
- Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, Republic of Singapore
| | - Peter R. Boag
- Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Andreas Hofmann
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
- Structural Chemistry Program, Eskitis Institute, Griffith University, Brisbane, Australia
| | - Robin B. Gasser
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| |
Collapse
|
53
|
Exploring molecular variation in Schistosoma japonicum in China. Sci Rep 2015; 5:17345. [PMID: 26621075 PMCID: PMC4664899 DOI: 10.1038/srep17345] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 10/26/2015] [Indexed: 12/12/2022] Open
Abstract
Schistosomiasis is a neglected tropical disease that affects more than 200 million people worldwide. The main disease-causing agents, Schistosoma japonicum, S. mansoni and S. haematobium, are blood flukes that have complex life cycles involving a snail intermediate host. In Asia, S. japonicum causes hepatointestinal disease (schistosomiasis japonica) and is challenging to control due to a broad distribution of its snail hosts and range of animal reservoir hosts. In China, extensive efforts have been underway to control this parasite, but genetic variability in S. japonicum populations could represent an obstacle to eliminating schistosomiasis japonica. Although a draft genome sequence is available for S. japonicum, there has been no previous study of molecular variation in this parasite on a genome-wide scale. In this study, we conducted the first deep genomic exploration of seven S. japonicum populations from mainland China, constructed phylogenies using mitochondrial and nuclear genomic data sets, and established considerable variation between some of the populations in genes inferred to be linked to key cellular processes and/or pathogen-host interactions. Based on the findings from this study, we propose that verifying intraspecific conservation in vaccine or drug target candidates is an important first step toward developing effective vaccines and chemotherapies against schistosomiasis.
Collapse
|
54
|
Almeida GT, Lage RCG, Anderson L, Venancio TM, Nakaya HI, Miyasato PA, Rofatto HK, Zerlotini A, Nakano E, Oliveira G, Verjovski-Almeida S. Synergy of Omeprazole and Praziquantel In Vitro Treatment against Schistosoma mansoni Adult Worms. PLoS Negl Trop Dis 2015; 9:e0004086. [PMID: 26402251 PMCID: PMC4581627 DOI: 10.1371/journal.pntd.0004086] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 08/25/2015] [Indexed: 01/01/2023] Open
Abstract
Background Treatment and morbidity control of schistosomiasis relies on a single drug, praziquantel (PZQ), and the selection of resistant worms under repeated treatment is a concern. Therefore, there is a pressing need to understand the molecular effects of PZQ on schistosomes and to investigate alternative or synergistic drugs against schistosomiasis. Methodology We used a custom-designed Schistosoma mansoni expression microarray to explore the effects of sublethal doses of PZQ on large-scale gene expression of adult paired males and females and unpaired mature females. We also assessed the efficacy of PZQ, omeprazole (OMP) or their combination against S. mansoni adult worms with a survival in vitro assay. Principal Findings We identified sets of genes that were affected by PZQ in paired and unpaired mature females, however with opposite gene expression patterns (up-regulated in paired and down-regulated in unpaired mature females), indicating that PZQ effects are heavily influenced by the mating status. We also identified genes that were similarly affected by PZQ in males and females. Functional analyses of gene interaction networks were performed with parasite genes that were differentially expressed upon PZQ treatment, searching for proteins encoded by these genes whose human homologs are targets of different drugs used for other diseases. Based on these results, OMP, a widely prescribed proton pump inhibitor known to target the ATP1A2 gene product, was chosen and tested. Sublethal doses of PZQ combined with OMP significantly increased worm mortality in vitro when compared with PZQ or OMP alone, thus evidencing a synergistic effect. Conclusions Functional analysis of gene interaction networks is an important approach that can point to possible novel synergistic drug candidates. We demonstrated the potential of this strategy by showing that PZQ in combination with OMP displayed increased efficiency against S. mansoni adult worms in vitro when compared with either drug alone. Schistosomiasis causes severe health problems in endemic areas of Africa, Southeast Asia, and Central and South America. Praziquantel is the drug of choice for treatment of at-risk populations; however, evolution of resistant worms under repeated treatment is of great concern. Combining praziquantel with another drug could not only increase efficacy of praziquantel, but also eventually hamper development of drug resistance. Our study reports the global praziquantel-induced transcriptional changes of Schistosoma mansoni adult worms in vitro, in the context of the mature female mating status (paired or unpaired). We identified sets of genes that were differentially affected in paired or unpaired mature females; we also identified genes that were similarly affected in males and females. Aiming to find possible new candidates to be tested as synergistic drugs, we used functional analysis of gene interaction networks to identify parasite genes whose expression was affected by praziquantel, and encode proteins whose human homologs are targets of different drugs already used to treat other diseases. This analysis suggested omeprazole, a widely prescribed drug, as a potential partner for praziquantel in a combination treatment. Finally, we demonstrated that this praziquantel-omeprazole combination resulted in increased worm lethality in vitro when compared with praziquantel or omeprazole alone.
Collapse
Affiliation(s)
- Giulliana T. Almeida
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Regina C. G. Lage
- Genomics and Computational Biology Group, Centro de Pesquisas René Rachou - FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
| | - Leticia Anderson
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Thiago M. Venancio
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Helder I. Nakaya
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | | | | | - Adhemar Zerlotini
- Genomics and Computational Biology Group, Centro de Pesquisas René Rachou - FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
| | | | - Guilherme Oliveira
- Genomics and Computational Biology Group, Centro de Pesquisas René Rachou - FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
- Vale Technology Institute, Belém, Pará, Brazil
| | - Sergio Verjovski-Almeida
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
- Instituto Butantan, São Paulo, São Paulo, Brazil
- * E-mail:
| |
Collapse
|
55
|
Chan JD, Agbedanu PN, Grab T, Zamanian M, Dosa PI, Day TA, Marchant JS. Ergot Alkaloids (Re)generate New Leads as Antiparasitics. PLoS Negl Trop Dis 2015; 9:e0004063. [PMID: 26367744 PMCID: PMC4569474 DOI: 10.1371/journal.pntd.0004063] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 08/17/2015] [Indexed: 12/04/2022] Open
Abstract
Praziquantel (PZQ) is a key therapy for treatment of parasitic flatworm infections of humans and livestock, but the mechanism of action of this drug is unresolved. Resolving PZQ-engaged targets and effectors is important for identifying new druggable pathways that may yield novel antiparasitic agents. Here we use functional, genetic and pharmacological approaches to reveal that serotonergic signals antagonize PZQ action in vivo. Exogenous 5-hydroxytryptamine (5-HT) rescued PZQ-evoked polarity and mobility defects in free-living planarian flatworms. In contrast, knockdown of a prevalently expressed planarian 5-HT receptor potentiated or phenocopied PZQ action in different functional assays. Subsequent screening of serotonergic ligands revealed that several ergot alkaloids possessed broad efficacy at modulating regenerative outcomes and the mobility of both free living and parasitic flatworms. Ergot alkaloids that phenocopied PZQ in regenerative assays to cause bipolar regeneration exhibited structural modifications consistent with serotonergic blockade. These data suggest that serotonergic activation blocks PZQ action in vivo, while serotonergic antagonists phenocopy PZQ action. Importantly these studies identify the ergot alkaloid scaffold as a promising structural framework for designing potent agents targeting parasitic bioaminergic G protein coupled receptors.
Collapse
Affiliation(s)
- John D. Chan
- Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Prince N. Agbedanu
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
| | - Thomas Grab
- Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Mostafa Zamanian
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
| | - Peter I. Dosa
- Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Timothy A. Day
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
| | - Jonathan S. Marchant
- Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota, United States of America
- Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, United States of America
| |
Collapse
|
56
|
Abdel-Monaem G, Farid A, Rabia I, El-Amir A. Evaluation of Echinostoma liei worm, metacercaria and redia antigens for schistosomiasis control. Exp Parasitol 2015; 157:23-9. [PMID: 26115938 DOI: 10.1016/j.exppara.2015.06.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 05/12/2015] [Accepted: 06/15/2015] [Indexed: 11/25/2022]
Abstract
While chemotherepeutic drugs, such as praziquantel, oxamniquine and metrifonate, are currently considered safe and effective drugs for schistosomiasis treatment, reinfection occurs frequently after drug treatment. Thus, a vaccine is sought to provide long-term treatment. Antigens from worm, metacercaria and redia of Echinostoma liei (E. liei) were purified using CNBr-activated Sepharose column, then used for immunization of mice prior to infection with Schistosomiasis mansoni. Worm burden, hepatic and intestinal eggs and oogram count was significantly reduced and that was reflected in normalization of liver architecture. This referred to a significant increase in the tested immunoglobulin level (IgM, IgG1 and IgG2).
Collapse
Affiliation(s)
- G Abdel-Monaem
- Zoology Dept., Faculty of Science, Cairo University, Giza, Egypt
| | - A Farid
- Zoology Dept., Faculty of Science, Cairo University, Giza, Egypt.
| | - I Rabia
- Parasitology Dept., Theodore Bilharz Research Institute, Giza, Egypt
| | - A El-Amir
- Zoology Dept., Faculty of Science, Cairo University, Giza, Egypt
| |
Collapse
|
57
|
Praziquantel in a clay nanoformulation shows more bioavailability and higher efficacy against murine Schistosoma mansoni infection. Antimicrob Agents Chemother 2015; 59:3501-8. [PMID: 25845870 DOI: 10.1128/aac.04875-14] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Accepted: 03/29/2015] [Indexed: 12/15/2022] Open
Abstract
Consideration of existing compounds always simplifies and shortens the long and difficult process of discovering new drugs specifically for diseases of developing countries, an approach that may add to the significant potential cost savings. This study focused on improving the biological characteristics of the already-existing antischistosomal praziquantel (PZQ) by incorporating it into montmorillonite (MMT) clay as a delivery carrier to overcome its known bioavailability drawbacks. The oral bioavailability of a PZQ-MMT clay nanoformulation and its in vivo efficacy against Schistosoma mansoni were investigated. The PZQ-MMT clay nanoformulation provided a preparation with a controlled release rate, a decrease in crystallinity, and an appreciable reduction in particle size. Uninfected and infected mice treated with PZQ-MMT clay showed 3.61- and 1.96-fold and 2.16- and 1.94-fold increases, respectively, in area under the concentration-time curve from 0 to 8 h (AUC0-8) and maximum concentration of drug in serum (Cmax), with a decrease in elimination rate constant (kel) by 2.84- and 1.35-fold and increases in the absorption rate constant (ka) and half-life (t1/2e) by 2.11- and 1.51-fold and 2.86- and 1.34-fold, respectively, versus the corresponding conventional PZQ-treated groups. This improved bioavailability has been expressed in higher efficacy of the drug, where the dose necessary to kill 50% of the worms was reduced by >3-fold (PZQ 50% effective dose [ED50] was 20.25 mg/kg of body weight for PZQ-MMT clay compared to 74.07 mg/kg for conventional PZQ), with significant reduction in total tissue egg load and increase in total immature, mature, and dead eggs in most of the drug-treated groups. This formulation showed better bioavailability, enhanced antischistosomal efficacy, and a safer profile despite the longer period of residence in the systemic circulation. Although the conventional drug's toxicity was not examined, animal mortality rates were not different between groups receiving the test PZQ-clay nanoformulation and conventional PZQ.
Collapse
|
58
|
Leow CY, Willis C, Hofmann A, Jones MK. Structure-function analysis of apical membrane-associated molecules of the tegument of schistosome parasites of humans: prospects for identification of novel targets for parasite control. Br J Pharmacol 2015; 172:1653-63. [PMID: 25176442 PMCID: PMC4376446 DOI: 10.1111/bph.12898] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 06/12/2014] [Accepted: 08/26/2014] [Indexed: 02/02/2023] Open
Abstract
Neglected tropical diseases are a group of some 17 diseases that afflict poor and predominantly rural people in developing nations. One significant disease that contributes to substantial morbidity in endemic areas is schistosomiasis, caused by infection with one of five species of blood fluke belonging to the trematode genus Schistosoma. Although there is one drug available for treatment of affected individuals in clinics, or for mass administration in endemic regions, there is a need for new therapies. A prominent target organ of schistosomes, either for drug or vaccine development, is the peculiar epithelial syncytium that forms the body wall (tegument) of this parasite. This dynamic layer is maintained and organized by concerted activity of a range of proteins, among which are the abundant tegumentary annexins. In this review, we will outline advances in structure-function analyses of these annexins, as a means to understanding tegument cell biology in host-parasite interaction and their potential exploitation as targets for anti-schistosomiasis therapies.
Collapse
Affiliation(s)
- Chiuan Yee Leow
- School of Veterinary Science, The University of QueenslandGatton, Queensland, Australia
- Infectious Diseases, QIMR Berghofer Medical Research InstituteHerston, Queensland, Australia
- Institute for Research in Molecular Medicine, Universiti Sains MalaysiaPenang, Malaysia
| | - Charlene Willis
- Infectious Diseases, QIMR Berghofer Medical Research InstituteHerston, Queensland, Australia
- Structural Chemistry Program, Eskitis Institute, Griffith UniversityBrisbane, Queensland, Australia
| | - Andreas Hofmann
- Structural Chemistry Program, Eskitis Institute, Griffith UniversityBrisbane, Queensland, Australia
- Faculty of Veterinary Science, The University of MelbourneParkville, Victoria, Australia
| | - Malcolm K Jones
- School of Veterinary Science, The University of QueenslandGatton, Queensland, Australia
| |
Collapse
|
59
|
Repurposing apoptosis-inducing cancer drugs to treat schistosomiasis. Future Med Chem 2015; 7:707-11. [DOI: 10.4155/fmc.14.164] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
60
|
Abstract
In the recent years, there has been a growing interest in the use of novel approaches for the treatment of parasitic diseases such as schistosomiasis. Among the different approaches used, organometallic compounds were found to offer unique opportunities in the design of antiparasitic drug candidates. A ferrocenyl derivative, namely ferroquine, has even entered clinical trials as a novel antimalarial. In this short review, we report on the studies describing the use of organometallic compounds against schistosomiasis.
Collapse
|
61
|
Drug-induced exposure of Schistosoma mansoni antigens SmCD59a and SmKK7. PLoS Negl Trop Dis 2015; 9:e0003593. [PMID: 25774883 PMCID: PMC4361651 DOI: 10.1371/journal.pntd.0003593] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 02/05/2015] [Indexed: 11/22/2022] Open
Abstract
Background Schistosomiasis is a serious health problem especially in developing countries and affects more than 243 million people. Only few anthelmintic drugs are available up to now. A major obstacle for drug treatment is the different developmental stages and the varying host compartments during worm development. Anthelmintic drugs have been tested mainly on adult schistosomes or freshly transformed cercariae. Knowledge concerning the larval stages is lacking. Methodology/Principal Findings In this study, we used in vitro-grown schistosomula (aged between 2 to 14 days) to investigate drug effects of the three anthelmintics praziquantel, artemether, and oxamniquine. Further, we analyzed the antibody accessibility of two exemplary schistosome antigens SmCD59a and SmKK7, before and after drug treatment. Our results demonstrated that praziquantel applied at a concentration of 1 μM inhibited development of all life stages. Application of 10 μM praziquantel led to dramatic morphological changes of all schistosomula. Artemether at 1 and 10 μM had differential effects depending on whether it was applied to 2-day as compared to 7- and 14-day schistosomula. While 2-day schistosomula were not killed but inhibited from further development, severe morphological damage was seen in 7- and 14-day schistosomula. Oxamniquine (1 and 10 μM) led to severe morphological impairment in all life stages. Analyzing the accessibility of the antigens SmCD59a and SmKK7 before drug treatment showed no antibody binding on living intact schistosomula. However, when schistosomula were treated with anthelmintics, both antigens became exposed on the larvae. Oxamniquine turned out to be most effective in promoting antibody binding to all schistosomula stages. Conclusion This study has revealed marked differences in anthelmintic drug effects against larvae. Drug treatment increases surface antigen presentation and renders larvae accessible to antibody attack. Schistosomiasis is one of the major parasitic diseases in developing countries and still causes 200,000 deaths per year. Mass drug administration programs with praziquantel, the drug of choice against schistosomiasis, are currently undertaken in Sub-Saharan Africa. Praziquantel, although efficient against adult worms, fails to cure early infection. The complex developmental stages of schistosomes and migration through varying host compartments with different local drug concentration are a challenge for drug treatment. After infecting their mammalian host, schistosomula traverse through skin and the vasculature of lung, liver and intestines. During their migration, they develop from larvae to paired adults in approximately 4 to 5 weeks. So far, drug effects have been analyzed on adult worms or freshly transformed schistosomula only. Information about the effects on the larval stages is lacking. We were able to transfer the larval development of the first three weeks into the culture dish. This tool can be used for the analysis of drug effects against schistosomula and for investigation of the accessibility, expression and localization of antigens. Rendering the parasite’s larvae vulnerable to the host’s immune system by increasing antigen presentation is an important aspect of drug activity. We demonstrate on in vitro-cultured Schistosoma mansoni larvae, that SmCD59a and SmKK7, as examples for hidden antigens, become accessible to antibodies following drug treatment.
Collapse
|
62
|
Ochodo EA, Gopalakrishna G, Spek B, Reitsma JB, van Lieshout L, Polman K, Lamberton P, Bossuyt PMM, Leeflang MMG. Circulating antigen tests and urine reagent strips for diagnosis of active schistosomiasis in endemic areas. Cochrane Database Syst Rev 2015; 2015:CD009579. [PMID: 25758180 PMCID: PMC4455231 DOI: 10.1002/14651858.cd009579.pub2] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Point-of-care (POC) tests for diagnosing schistosomiasis include tests based on circulating antigen detection and urine reagent strip tests. If they had sufficient diagnostic accuracy they could replace conventional microscopy as they provide a quicker answer and are easier to use. OBJECTIVES To summarise the diagnostic accuracy of: a) urine reagent strip tests in detecting active Schistosoma haematobium infection, with microscopy as the reference standard; and b) circulating antigen tests for detecting active Schistosoma infection in geographical regions endemic for Schistosoma mansoni or S. haematobium or both, with microscopy as the reference standard. SEARCH METHODS We searched the electronic databases MEDLINE, EMBASE, BIOSIS, MEDION, and Health Technology Assessment (HTA) without language restriction up to 30 June 2014. SELECTION CRITERIA We included studies that used microscopy as the reference standard: for S. haematobium, microscopy of urine prepared by filtration, centrifugation, or sedimentation methods; and for S. mansoni, microscopy of stool by Kato-Katz thick smear. We included studies on participants residing in endemic areas only. DATA COLLECTION AND ANALYSIS Two review authors independently extracted data, assessed quality of the data using QUADAS-2, and performed meta-analysis where appropriate. Using the variability of test thresholds, we used the hierarchical summary receiver operating characteristic (HSROC) model for all eligible tests (except the circulating cathodic antigen (CCA) POC for S. mansoni, where the bivariate random-effects model was more appropriate). We investigated heterogeneity, and carried out indirect comparisons where data were sufficient. Results for sensitivity and specificity are presented as percentages with 95% confidence intervals (CI). MAIN RESULTS We included 90 studies; 88 from field settings in Africa. The median S. haematobium infection prevalence was 41% (range 1% to 89%) and 36% for S. mansoni (range 8% to 95%). Study design and conduct were poorly reported against current standards. Tests for S. haematobium Urine reagent test strips versus microscopyCompared to microscopy, the detection of microhaematuria on test strips had the highest sensitivity and specificity (sensitivity 75%, 95% CI 71% to 79%; specificity 87%, 95% CI 84% to 90%; 74 studies, 102,447 participants). For proteinuria, sensitivity was 61% and specificity was 82% (82,113 participants); and for leukocyturia, sensitivity was 58% and specificity 61% (1532 participants). However, the difference in overall test accuracy between the urine reagent strips for microhaematuria and proteinuria was not found to be different when we compared separate populations (P = 0.25), or when direct comparisons within the same individuals were performed (paired studies; P = 0.21).When tests were evaluated against the higher quality reference standard (when multiple samples were analysed), sensitivity was marginally lower for microhaematuria (71% vs 75%) and for proteinuria (49% vs 61%). The specificity of these tests was comparable. Antigen assayCompared to microscopy, the CCA test showed considerable heterogeneity; meta-analytic sensitivity estimate was 39%, 95% CI 6% to 73%; specificity 78%, 95% CI 55% to 100% (four studies, 901 participants). Tests for S. mansoni Compared to microscopy, the CCA test meta-analytic estimates for detecting S. mansoni at a single threshold of trace positive were: sensitivity 89% (95% CI 86% to 92%); and specificity 55% (95% CI 46% to 65%; 15 studies, 6091 participants) Against a higher quality reference standard, the sensitivity results were comparable (89% vs 88%) but specificity was higher (66% vs 55%). For the CAA test, sensitivity ranged from 47% to 94%, and specificity from 8% to 100% (4 studies, 1583 participants). AUTHORS' CONCLUSIONS Among the evaluated tests for S. haematobium infection, microhaematuria correctly detected the largest proportions of infections and non-infections identified by microscopy.The CCA POC test for S. mansoni detects a very large proportion of infections identified by microscopy, but it misclassifies a large proportion of microscopy negatives as positives in endemic areas with a moderate to high prevalence of infection, possibly because the test is potentially more sensitive than microscopy.
Collapse
Affiliation(s)
- Eleanor A Ochodo
- Academic Medical Center, University of AmsterdamDepartment of Clinical Epidemiology, Biostatistics and BioinformaticsAmsterdamNetherlands1100 DD
- Stellenbosch UniversityCentre for Evidence‐based Health Care, Faculty of Medicine and Health SciencesCape TownSouth Africa
| | - Gowri Gopalakrishna
- Academic Medical Center, University of AmsterdamDepartment of Clinical Epidemiology, Biostatistics and BioinformaticsAmsterdamNetherlands1100 DD
| | - Bea Spek
- Academic Medical Center, University of AmsterdamDepartment of Clinical Epidemiology, Biostatistics and BioinformaticsAmsterdamNetherlands1100 DD
- Hanze University GroningenDepartment of Speech and Language PathologyEyssoniuspleinGroningenNetherlands
| | - Johannes B Reitsma
- University Medical Center UtrechtJulius Center for Health Sciences and Primary CarePO Box 85500UtrechtNetherlands3508 GA Utrecht
| | - Lisette van Lieshout
- Leiden University Medical CenterDepartment of ParasitologyPO Box 9600LeidenNetherlands2300 RC
| | - Katja Polman
- Institute of Tropical MedicineDepartment of Biomedical SciencesNationalestraat 155AntwerpBelgium2000
| | - Poppy Lamberton
- Imperial College LondonDepartment of Infectious Disease EpidemiologySt. Mary's Campus, Norfolk PlaceLondonUKW2 1PG
| | - Patrick MM Bossuyt
- Academic Medical Center, University of AmsterdamDepartment of Clinical Epidemiology, Biostatistics and BioinformaticsAmsterdamNetherlands1100 DD
| | - Mariska MG Leeflang
- Academic Medical Center, University of AmsterdamDepartment of Clinical Epidemiology, Biostatistics and BioinformaticsAmsterdamNetherlands1100 DD
| | | |
Collapse
|
63
|
Modelling the effects of mass drug administration on the molecular epidemiology of schistosomes. ADVANCES IN PARASITOLOGY 2015; 87:293-327. [PMID: 25765198 DOI: 10.1016/bs.apar.2014.12.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
As national governments scale up mass drug administration (MDA) programs aimed to combat neglected tropical diseases (NTDs), novel selection pressures on these parasites increase. To understand how parasite populations are affected by MDA and how to maximize the success of control programmes, it is imperative for epidemiological, molecular and mathematical modelling approaches to be combined. Modelling of parasite population genetic and genomic structure, particularly of the NTDs, has been limited through the availability of only a few molecular markers to date. The landscape of infectious disease research is being dramatically reshaped by next-generation sequencing technologies and our understanding of how repeated selective pressures are shaping parasite populations is radically altering. Genomics can provide high-resolution data on parasite population structure, and identify how loci may contribute to key phenotypes such as virulence and/or drug resistance. We discuss the incorporation of genetic and genomic data, focussing on the recently sequenced Schistosoma spp., into novel mathematical transmission models to inform our understanding of the impact of MDA and other control methods. We summarize what is known to date, the models that exist and how population genetics has given us an understanding of the effects of MDA on the parasites. We consider how genetic and genomic data have the potential to shape future research, highlighting key areas where data are lacking, and how future molecular epidemiology knowledge can aid understanding of transmission dynamics and the effects of MDA, ultimately informing public health policy makers of the best interventions for NTDs.
Collapse
|
64
|
Barakat R, Abou El-Ela NE, Sharaf S, El Sagheer O, Selim S, Tallima H, Bruins MJ, Hadley KB, El Ridi R. Efficacy and safety of arachidonic acid for treatment of school-age children in Schistosoma mansoni high-endemicity regions. Am J Trop Med Hyg 2015; 92:797-804. [PMID: 25624403 PMCID: PMC4385776 DOI: 10.4269/ajtmh.14-0675] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Accepted: 12/19/2014] [Indexed: 02/04/2023] Open
Abstract
Arachidonic acid (ARA), an omega-6 fatty acid, is a potent schistosomicide that displayed significant and safe therapeutic effects in Schistosoma mansoni-infected schoolchildren in S. mansoni low-prevalence regions. We here report on ARA efficacy and safety in treatment of schoolchildren in S. mansoni high-endemicity areas of Kafr El Sheikh, Egypt. The study was registered with ClinicalTrials.gov (NCT02144389). In total, 268 schoolchildren with light, moderate, or heavy S. mansoni infection were assigned to three study arms of 87, 91, and 90 children and received a single dose of 40 mg/kg praziquantel (PZQ), ARA (10 mg/kg per day for 15 days), or PZQ combined with ARA, respectively. The children were examined before and after treatment for stool parasite egg counts and blood biochemical, hematological, and immunological parameters. ARA, like PZQ, induced moderate cure rates (50% and 60%, respectively) in schoolchildren with light infection and modest cure rates (21% and 20%, respectively) in schoolchildren with high infection. PZQ and ARA combined elicited 83% and 78% cure rates in children with light and heavy infection, respectively. Biochemical and immunological profiles were either unchanged or ameliorated after ARA therapy. Combination of PZQ and ARA might be useful for treatment of children with schistosomiasis in high-endemicity regions.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Rashika El Ridi
- *Address correspondence to Rashika El Ridi, Zoology Department, Faculty of Science, Cairo University, Cairo 12613, Egypt. E-mail:
| |
Collapse
|
65
|
Carneiro TR, Peralta RHS, Pinheiro MCC, Oliveira SMD, Peralta JM, Bezerra FSM. A conventional polymerase chain reaction-based method for the diagnosis of human schistosomiasis in stool samples from individuals in a low-endemicity area. Mem Inst Oswaldo Cruz 2015; 108:1037-44. [PMID: 24402156 PMCID: PMC4005555 DOI: 10.1590/0074-0276130202] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 10/07/2013] [Indexed: 01/17/2023] Open
Abstract
The aim of this study was to evaluate the efficacy of a polymerase chain reaction
(PCR)-based method to detect Schistosoma mansoni DNA in stool
samples from individuals living in a low-endemicity area in Brazil. Of the 125
initial stool samples, 80 were ELISA reactive and eggs were identified in 19 of the
samples by parasitological examination. For the PCR evaluations, 56 stool samples
were selected and divided into five groups. Groups I-IV were scored negative for
S. mansoni eggs by parasitological examination. Groups I and II
were ELISA reactive, whereas Groups III and IV were ELISA nonreactive. Groups II and
III were positive for other intestinal parasites. PCR testing scored eight samples as
positive from these four groups. Group V represented the S. mansoni
-positive group and it included ELISA-reactive samples that were scored positive for
S. mansoni by one or more parasitological examinations (6/19 were
positive by Kato-Katz method, 9/17 by saline gradient and 10/13 by Helmintex®). PCR
scored 13 of these 19 samples as positive for S. mansoni . We
conclude that while none of these methods yielded 100% sensitivity, a combination of
techniques should be effective for improving the detection of S.
mansoni infection in low-endemicity areas.
Collapse
Affiliation(s)
| | | | | | | | - José Mauro Peralta
- Departamento de Imunologia, Instituto de Microbiologia Paulo de Goes, Universidade Federal do Rio de Janeiro, Brasil, Rio de JaneiroRJ
| | | |
Collapse
|
66
|
Genome mining offers a new starting point for parasitology research. Parasitol Res 2015; 114:399-409. [PMID: 25563615 DOI: 10.1007/s00436-014-4299-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 12/23/2014] [Indexed: 12/11/2022]
Abstract
Parasites including helminthes, protozoa, and medical arthropod vectors are a major cause of global infectious diseases, affecting one-sixth of the world's population, which are responsible for enormous levels of morbidity and mortality important and remain impediments to economic development especially in tropical countries. Prevalent drug resistance, lack of highly effective and practical vaccines, as well as specific and sensitive diagnostic markers are proving to be challenging problems in parasitic disease control in most parts of the world. The impressive progress recently made in genome-wide analysis of parasites of medical importance, including trematodes of Clonorchis sinensis, Opisthorchis viverrini, Schistosoma haematobium, S. japonicum, and S. mansoni; nematodes of Brugia malayi, Loa loa, Necator americanus, Trichinella spiralis, and Trichuris suis; cestodes of Echinococcus granulosus, E. multilocularis, and Taenia solium; protozoa of Babesia bovis, B. microti, Cryptosporidium hominis, Eimeria falciformis, E. histolytica, Giardia intestinalis, Leishmania braziliensis, L. donovani, L. major, Plasmodium falciparum, P. vivax, Trichomonas vaginalis, Trypanosoma brucei and T. cruzi; and medical arthropod vectors of Aedes aegypti, Anopheles darlingi, A. sinensis, and Culex quinquefasciatus, have been systematically covered in this review for a comprehensive understanding of the genetic information contained in nuclear, mitochondrial, kinetoplast, plastid, or endosymbiotic bacterial genomes of parasites, further valuable insight into parasite-host interactions and development of promising novel drug and vaccine candidates and preferable diagnostic tools, thereby underpinning the prevention and control of parasitic diseases.
Collapse
|
67
|
Greenberg RM. Ion channels and drug transporters as targets for anthelmintics. CURRENT CLINICAL MICROBIOLOGY REPORTS 2014; 1:51-60. [PMID: 25554739 PMCID: PMC4278637 DOI: 10.1007/s40588-014-0007-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Infections with parasitic helminths such as schistosomes and soil-transmitted nematodes are hugely prevalent and responsible for a major portion of the global health and economic burdens associated with neglected tropical diseases. In addition, many of these parasites infect livestock and plants used in agriculture, resulting in further impoverishment. Treatment and control of these pathogens rely on anthelmintic drugs, which are few in number, and against which drug resistance can develop rapidly. The neuromuscular system of the parasite, and in particular, the ion channels and associated receptors underlying excitation and signaling, have proven to be outstanding targets for anthelmintics. This review will survey the different ion channels found in helminths, focusing on their unique characteristics and pharmacological sensitivities. It will also briefly review the literature on helminth multidrug efflux that may modulate parasite susceptibility to anthelmintics and may prove useful targets for new or repurposed agents that can enhance parasite drug susceptibility and perhaps overcome drug resistance.
Collapse
Affiliation(s)
- Robert M Greenberg
- Department of Pathobiology School of Veterinary Medicine University of Pennsylvania 3800 Spruce Street Philadelphia PA 19104 Tel: 215-898-5678
| |
Collapse
|
68
|
Inhibition or knockdown of ABC transporters enhances susceptibility of adult and juvenile schistosomes to Praziquantel. PLoS Negl Trop Dis 2014; 8:e3265. [PMID: 25330312 PMCID: PMC4199547 DOI: 10.1371/journal.pntd.0003265] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Accepted: 09/10/2014] [Indexed: 12/01/2022] Open
Abstract
Parasitic flatworms of the genus Schistosoma cause schistosomiasis, a neglected tropical disease that affects hundreds of millions. Treatment of schistosomiasis depends almost entirely on the drug praziquantel (PZQ). Though essential to treating and controlling schistosomiasis, a major limitation of PZQ is that it is not active against immature mammalian-stage schistosomes. Furthermore, there are reports of field isolates with heritable reductions in PZQ susceptibility, and researchers have selected for PZQ-resistant schistosomes in the laboratory. P-glycoprotein (Pgp; ABCB1) and other ATP binding cassette (ABC) transporters remove a wide variety of toxins and xenobiotics from cells, and have been implicated in multidrug resistance (MDR). Changes in ABC transporter structure or expression levels are also associated with reduced drug susceptibility in parasitic helminths, including schistosomes. Here, we show that the activity of PZQ against schistosome adults and juveniles ex vivo is potentiated by co-administration of either the highly potent Pgp inhibitor tariquidar or combinations of inhibitors targeting multiple ABC multidrug transporters. Adult worms exposed to sublethal PZQ concentrations remain active, but co-administration of ABC transporter inhibitors results in complete loss of motility and disruption of the tegument. Notably, juvenile schistosomes (3–4 weeks post infection), normally refractory to 2 µM PZQ, become paralyzed when transporter inhibitors are added in combination with the PZQ. Experiments using the fluorescent PZQ derivative (R)-PZQ-BODIPY are consistent with the transporter inhibitors increasing effective intraworm concentrations of PZQ. Adult worms in which expression of ABC transporters has been suppressed by RNA interference show increased responsiveness to PZQ and increased retention of (R)-PZQ-BODIPY consistent with an important role for these proteins in setting levels of PZQ susceptibility. These results indicate that parasite ABC multidrug transporters might serve as important targets for enhancing the action of PZQ. They also suggest a potentially novel and readily-available strategy for overcoming reduced PZQ susceptibility of schistosomes. Schistosomes are parasitic flatworms that cause schistosomiasis, a tropical disease affecting hundreds of millions worldwide. Praziquantel (PZQ) is the current drug of choice against schistosomiasis, and, indeed, is the only approved antischistosomal treatment available in most parts of the world. Though effective overall, PZQ has limitations, including its lack of activity against immature schistosomes. Furthermore, reported cure rates in the field are often below optimal levels, and there is increasing evidence that schistosomes can become resistant to the drug. ABC transporters such as P-glycoprotein are efflux transporters that mediate detoxification of cells via removal of toxins and xenobiotics, including drugs. They underlie multidrug resistance in mammalian cells, and are also associated with drug resistance in parasitic worms, including schistosomes. Here, we show that compounds that inhibit these efflux transporters potentiate the activity of PZQ against schistosomes, including normally PZQ-insensitive juvenile worms. Similarly, suppressing expression of these transporters also increases adult worm responsiveness to PZQ. Our experiments may provide insights into the role of these drug transporters in PZQ action, and could also translate into new therapeutic strategies for augmenting treatment of schistosome infections and overcoming drug resistance.
Collapse
|
69
|
Greenberg RM. Schistosome ABC multidrug transporters: From pharmacology to physiology. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2014; 4:301-9. [PMID: 25516841 PMCID: PMC4266782 DOI: 10.1016/j.ijpddr.2014.09.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The genuine and hypothesized roles of schistosome ABC transporters are reviewed. Evidence suggesting a role for transporters in schistosome drug susceptibility is discussed. Potential roles of ABC transporters in normal schistosome biology are outlined.
Praziquantel (PZQ) is essentially the only drug currently available for treatment and control of schistosomiasis, a disease affecting hundreds of millions worldwide. Though highly effective overall, PZQ has limitations, most notably its significant lack of activity against immature schistosomes. Furthermore, the availability of only a single drug for a disease of this magnitude makes reports of PZQ-resistant isolates particularly troubling. ATP-binding cassette (ABC) multidrug transporters such as P-glycoprotein (Pgp; ABCB1) are efflux transporters that underlie multidrug resistance (MDR); changes in their expression or structure are also associated with drug resistance in parasites, including helminths. This review will discuss the role these transporters might play in modulating schistosome susceptibility to PZQ, and the implications for developing new or repurposed treatments that enhance the efficacy of PZQ. However, in addition to influencing drug susceptibility, ABC transporters play important roles in several critical physiological functions such as excretion and maintenance of permeability barriers. They also transport signaling molecules with high affinity, and several lines of evidence implicate mammalian transporters in a diverse array of physiological functions, including regulation of immune responses. Like their mammalian counterparts, schistosome ABC transporters appear to be involved in functions critical to the parasite, including excretory activity and reproduction, and we hypothesize that they underlie at least some aspects of parasite–host interactions. Thus, in addition to their potential as targets for enhancers of PZQ susceptibility, these transporters might also serve as candidate targets for agents that disrupt the parasite life cycle and act as antischistosomals on their own.
Collapse
Affiliation(s)
- Robert M Greenberg
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce Street, PA 19104, USA
| |
Collapse
|
70
|
Bruschi F. The challenge of antiparasitic resistance. J Glob Antimicrob Resist 2014; 2:131-132. [PMID: 27873718 DOI: 10.1016/j.jgar.2014.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Fabrizio Bruschi
- Department of Translational Research, Università di Pisa, School of Medicine, Pisa, Italy.
| |
Collapse
|
71
|
Multidrug resistance: an emerging crisis. Interdiscip Perspect Infect Dis 2014; 2014:541340. [PMID: 25140175 PMCID: PMC4124702 DOI: 10.1155/2014/541340] [Citation(s) in RCA: 279] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 07/03/2014] [Indexed: 01/15/2023] Open
Abstract
The resistance among various microbial species (infectious agents) to different antimicrobial drugs has emerged as a cause of public health threat all over the world at a terrifying rate. Due to the pacing advent of new resistance mechanisms and decrease in efficiency of treating common infectious diseases, it results in failure of microbial response to standard treatment, leading to prolonged illness, higher expenditures for health care, and an immense risk of death. Almost all the capable infecting agents (e.g., bacteria, fungi, virus, and parasite) have employed high levels of multidrug resistance (MDR) with enhanced morbidity and mortality; thus, they are referred to as “super bugs.” Although the development of MDR is a natural phenomenon, the inappropriate use of antimicrobial drugs, inadequate sanitary conditions, inappropriate food-handling, and poor infection prevention and control practices contribute to emergence of and encourage the further spread of MDR. Considering the significance of MDR, this paper, emphasizes the problems associated with MDR and the need to understand its significance and mechanisms to combat microbial infections.
Collapse
|
72
|
Roquis D, Lepesant JMJ, Villafan E, Boissier J, Vieira C, Cosseau C, Grunau C. Exposure to hycanthone alters chromatin structure around specific gene functions and specific repeats in Schistosoma mansoni. Front Genet 2014; 5:207. [PMID: 25076965 PMCID: PMC4099960 DOI: 10.3389/fgene.2014.00207] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 06/18/2014] [Indexed: 11/23/2022] Open
Abstract
Schistosoma mansoni is a parasitic plathyhelminth responsible for intestinal schistosomiasis (or bilharzia), a disease affecting 67 million people worldwide and causing an important economic burden. The schistosomicides hycanthone, and its later proxy oxamniquine, were widely used for treatments in endemic areas during the twentieth century. Recently, the mechanism of action, as well as the genetic origin of a stably and Mendelian inherited resistance for both drugs was elucidated in two strains. However, several observations suggested early on that alternative mechanisms might exist, by which resistance could be induced for these two drugs in sensitive lines of schistosomes. This induced resistance appeared rapidly, within the first generation, but was metastable (not stably inherited). Epigenetic inheritance could explain such a phenomenon and we therefore re-analyzed the historical data with our current knowledge of epigenetics. In addition, we performed new experiments such as ChIP-seq on hycanthone treated worms. We found distinct chromatin structure changes between sensitive worms and induced resistant worms from the same strain. No specific pathway was discovered, but genes in which chromatin structure modifications were observed are mostly associated with transport and catabolism, which makes sense in the context of the elimination of the drug. Specific differences were observed in the repetitive compartment of the genome. We finally describe what types of experiments are needed to understand the complexity of heritability that can be based on genetic and/or epigenetic mechanisms for drug resistance in schistosomes.
Collapse
Affiliation(s)
- David Roquis
- Département de Biologie, Université de Perpignan Via DomitiaPerpignan, France
- CNRS, UMR 5244, Écologie et Évolution des Interactions (2EI)Perpignan, France
| | - Julie M. J. Lepesant
- Département de Biologie, Université de Perpignan Via DomitiaPerpignan, France
- CNRS, UMR 5244, Écologie et Évolution des Interactions (2EI)Perpignan, France
| | - Emanuel Villafan
- CNRS, UMR 5558, Laboratoire de Biométrie et Biologie Évolutive, Département de Biologie, Université Lyon 1Villeurbane, France
- Red de Estudios Moleculares Avanzados, Instituto de Ecología A.C.Xalapa, México
| | - Jérôme Boissier
- Département de Biologie, Université de Perpignan Via DomitiaPerpignan, France
- Red de Estudios Moleculares Avanzados, Instituto de Ecología A.C.Xalapa, México
| | - Cristina Vieira
- CNRS, UMR 5558, Laboratoire de Biométrie et Biologie Évolutive, Département de Biologie, Université Lyon 1Villeurbane, France
- Département de Biologie, Institut Universitaire de FranceParis, France
| | - Céline Cosseau
- Département de Biologie, Université de Perpignan Via DomitiaPerpignan, France
- CNRS, UMR 5244, Écologie et Évolution des Interactions (2EI)Perpignan, France
| | - Christoph Grunau
- Département de Biologie, Université de Perpignan Via DomitiaPerpignan, France
- CNRS, UMR 5244, Écologie et Évolution des Interactions (2EI)Perpignan, France
| |
Collapse
|
73
|
Hai Y, Edwards JE, Van Zandt MC, Hoffmann KF, Christianson DW. Crystal structure of Schistosoma mansoni arginase, a potential drug target for the treatment of schistosomiasis. Biochemistry 2014; 53:4671-84. [PMID: 25007099 PMCID: PMC4138072 DOI: 10.1021/bi5004519] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The X-ray crystal structure of arginase from Schistosoma mansoni (SmARG) and the structures of its complexes with several amino acid inhibitors have been determined at atomic resolution. SmARG is a binuclear manganese metalloenzyme that catalyzes the hydrolysis of l-arginine to form l-ornithine and urea, and this enzyme is upregulated in all forms of the parasite that interact with the human host. Current hypotheses suggest that parasitic arginases could play a role in host immune evasion by depleting pools of substrate l-arginine that would otherwise be utilized for NO biosynthesis and NO-dependent processes in the immune response. Although the amino acid sequence of SmARG is only 42% identical with that of human arginase I, residues important for substrate binding and catalysis are strictly conserved. In general, classical amino acid inhibitors such as 2(S)-amino-6-boronohexanoic acid (ABH) tend to bind more weakly to SmARG than to human arginase I despite identical inhibitor binding modes in each enzyme active site. The identification of a patch on the enzyme surface capable of accommodating the additional Cα substitutent of an α,α-disubstituted amino acid inhibitor suggests that such inhibitors could exhibit higher affinity and biological activity. The structures of SmARG complexed with two different α,α-disubstituted derivatives of ABH are presented and provide a proof of concept for this approach in the enhancement of enzyme-inhibitor affinity.
Collapse
Affiliation(s)
- Yang Hai
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104-6323, United States
| | | | | | | | | |
Collapse
|
74
|
Apoptosis in schistosomes: toward novel targets for the treatment of schistosomiasis. Trends Parasitol 2014; 30:75-84. [DOI: 10.1016/j.pt.2013.12.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 11/29/2013] [Accepted: 12/06/2013] [Indexed: 12/25/2022]
|
75
|
Preventive chemotherapy for schistosomiasis and soil-transmitted helminthiasis by cotreatment with praziquantel and albendazole. ACTA ACUST UNITED AC 2014. [DOI: 10.4155/cli.13.128] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
76
|
Valentim CLL, Cioli D, Chevalier FD, Cao X, Taylor AB, Holloway SP, Pica-Mattoccia L, Guidi A, Basso A, Tsai IJ, Berriman M, Carvalho-Queiroz C, Almeida M, Aguilar H, Frantz DE, Hart PJ, LoVerde PT, Anderson TJC. Genetic and molecular basis of drug resistance and species-specific drug action in schistosome parasites. Science 2013; 342:1385-9. [PMID: 24263136 PMCID: PMC4136436 DOI: 10.1126/science.1243106] [Citation(s) in RCA: 119] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Oxamniquine resistance evolved in the human blood fluke (Schistosoma mansoni) in Brazil in the 1970s. We crossed parental parasites differing ~500-fold in drug response, determined drug sensitivity and marker segregation in clonally derived second-generation progeny, and identified a single quantitative trait locus (logarithm of odds = 31) on chromosome 6. A sulfotransferase was identified as the causative gene by using RNA interference knockdown and biochemical complementation assays, and we subsequently demonstrated independent origins of loss-of-function mutations in field-derived and laboratory-selected resistant parasites. These results demonstrate the utility of linkage mapping in a human helminth parasite, while crystallographic analyses of protein-drug interactions illuminate the mode of drug action and provide a framework for rational design of oxamniquine derivatives that kill both S. mansoni and S. haematobium, the two species responsible for >99% of schistosomiasis cases worldwide.
Collapse
Affiliation(s)
- Claudia L L Valentim
- Departments of Biochemistry and Pathology, University of Texas Health Science Center, San Antonio, TX 78229, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
77
|
Wang W, Li TY, Ji Y, Qu GL, Qian YL, Li HJ, Dai JR, Liang YS. Efficacy of artemether and artesunate in mice infected with praziquantel non-susceptible isolate of Schistosoma japonicum. Parasitol Res 2013; 113:925-31. [DOI: 10.1007/s00436-013-3724-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 11/27/2013] [Indexed: 10/25/2022]
|
78
|
Patra M, Ingram K, Leonidova A, Pierroz V, Ferrari S, Robertson MN, Todd MH, Keiser J, Gasser G. In Vitro Metabolic Profile and in Vivo Antischistosomal Activity Studies of (η6-Praziquantel)Cr(CO)3 Derivatives. J Med Chem 2013; 56:9192-8. [DOI: 10.1021/jm401287m] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
| | - Katrin Ingram
- Department
of Medical Parasitology and Infection Biology, Swiss Tropical and
Public Health Institute, CH-4051 Basel, Switzerland and University of Basel, P.O. Box, CH-4003 Basel, Switzerland
| | | | | | | | - Murray N. Robertson
- School
of Chemistry, The University of Sydney, New South Wales 2006, Australia
| | - Matthew H. Todd
- School
of Chemistry, The University of Sydney, New South Wales 2006, Australia
| | - Jennifer Keiser
- Department
of Medical Parasitology and Infection Biology, Swiss Tropical and
Public Health Institute, CH-4051 Basel, Switzerland and University of Basel, P.O. Box, CH-4003 Basel, Switzerland
| | | |
Collapse
|
79
|
|