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Walvekar S, Anwar A, Anwar A, Sridewi N, Khalid M, Yow YY, Khan NA. Anti-amoebic potential of azole scaffolds and nanoparticles against pathogenic Acanthamoeba. Acta Trop 2020; 211:105618. [PMID: 32628912 DOI: 10.1016/j.actatropica.2020.105618] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 07/02/2020] [Accepted: 07/02/2020] [Indexed: 12/20/2022]
Abstract
Acanthamoeba spp. are free living amoeba (FLA) which are widely distributed in nature. They are opportunistic parasites and can cause severe infections to the eye, skin and central nervous system. The advances in drug discovery and modifications in the chemotherapeutic agents have shown little improvement in morbidity and mortality rates associated with Acanthamoeba infections. The mechanism-based process of drug discovery depends on the molecular drug targets present in the signaling pathways in the genome. Synthetic libraries provide a platform for broad spectrum of activities due to their desired structural modifications. Azoles, originally a class of synthetic anti-fungal drugs, disrupt the fungal cell membrane by inhibiting the biosynthesis of ergosterol through the inhibition of cytochrome P450 dependent 14α-lanosterol, a key step of the sterol pathway. Acanthamoeba and fungi share the presence of similar sterol intermediate, as ergosterol is also the major end-product in the sterol biosynthesis in Acanthamoeba. Sterols present in the eukaryotic cell membrane are one of the most essential lipids and exhibit important structural and signaling functions. Therefore, in this review we highlight the importance of specific targeting of ergosterol present in Acanthamoebic membrane by azole compounds for amoebicidal activity. Previously, azoles have also been repurposed to report antimicrobial, antiparasitic and antibacterial properties. Moreover, by loading the azoles into nanoparticles through advanced techniques in nanotechnology, such as physical encapsulation, adsorption, or chemical conjugation, the pharmacokinetics and therapeutic index of the drugs can be significantly improved. The current review proposes an important strategy to target Acanthamoeba using synthetic libraries of azoles and their conjugated nanoparticles for the first time.
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Guzmán-Téllez P, Martínez-Castillo M, Flores-Huerta N, Rosales-Morgan G, Pacheco-Yépez J, la Garza MD, Serrano-Luna J, Shibayama M. Lectins as virulence factors in Entamoeba histolytica and free-living amoebae. Future Microbiol 2020; 15:919-936. [PMID: 32716210 DOI: 10.2217/fmb-2019-0275] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Currently, there is growing interest in the identification and purification of microbial lectins due to their involvement in the pathogenicity mechanisms of pathogens, such as Entamoeba histolytica and free-living amoebae. The Gal/GalNAc lectin from E. histolytica participates in adhesion, cytotoxicity and regulation of immune responses. Furthermore, mannose- and galactose-binding protein have been described in Acanthamoeba castellanii and Balamuthia mandrillaris, respectively and they also contribute to host damage. Finally, in Naegleria fowleri, molecules containing mannose and fucose are implicated in adhesion and cytotoxicity. Considering their relevance in the pathogenesis of the diseases caused by these protozoa, lectins appear to be promising targets in the diagnosis, vaccination and treatment of these infections.
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Affiliation(s)
- Paula Guzmán-Téllez
- Department of Infectomics & Molecular Pathogenesis, Center for Research & Advanced Studies of The National Polytechnic Institute, Av. IPN 2508, Mexico City 07360, Mexico
| | - Moisés Martínez-Castillo
- Department of Infectomics & Molecular Pathogenesis, Center for Research & Advanced Studies of The National Polytechnic Institute, Av. IPN 2508, Mexico City 07360, Mexico
- Department of Experimental Medicine, Liver, Pancreas & Motility Laboratory (HIPAM), School of Medicine, National Autonomous University of Mexico (UNAM) Mexico City, Mexico
| | - Nadia Flores-Huerta
- Department of Infectomics & Molecular Pathogenesis, Center for Research & Advanced Studies of The National Polytechnic Institute, Av. IPN 2508, Mexico City 07360, Mexico
| | - Gabriela Rosales-Morgan
- Department of Infectomics & Molecular Pathogenesis, Center for Research & Advanced Studies of The National Polytechnic Institute, Av. IPN 2508, Mexico City 07360, Mexico
| | - Judith Pacheco-Yépez
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Ciudad de México, México
| | - Mireya de la Garza
- Department of Cell Biology, Center for Research & Advanced Studies of The National Polytechnic Institute, Av. IPN 2508, Mexico City 07360, Mexico
| | - Jesús Serrano-Luna
- Department of Cell Biology, Center for Research & Advanced Studies of The National Polytechnic Institute, Av. IPN 2508, Mexico City 07360, Mexico
| | - Mineko Shibayama
- Department of Infectomics & Molecular Pathogenesis, Center for Research & Advanced Studies of The National Polytechnic Institute, Av. IPN 2508, Mexico City 07360, Mexico
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Anwar A, Siddiqui R, Khan NA. Whole Organism Model to Study Molecular Mechanisms of Differentiation and Dedifferentiation. BIOLOGY 2020; 9:E79. [PMID: 32316619 PMCID: PMC7235994 DOI: 10.3390/biology9040079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/14/2020] [Accepted: 04/15/2020] [Indexed: 12/25/2022]
Abstract
Cancer recurrence has remained a significant challenge, despite advances in therapeutic approaches. In part, this is due to our incomplete understanding of the biology of cancer stem cells and the underlying molecular mechanisms. The phenomenon of differentiation and dedifferentiation (phenotypic switching) is not only unique to stem cells but it is also observed in several other organisms, as well as evolutionary-related microbes. Here, we propose the use of a primitive eukaryotic unicellular organism, Acanthamoeba castellanii, as a model to study the molecular mechanisms of cellular differentiation and dedifferentiation.
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Affiliation(s)
- Areeba Anwar
- Department of Biological Sciences, School of Science and Technology, Sunway University, Bandar Sunway 47500, Malaysia;
| | - Ruqaiyyah Siddiqui
- Department of Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, University City 26666, UAE;
| | - Naveed Ahmed Khan
- Department of Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, University City 26666, UAE;
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Ehrenkaufer G, Li P, Stebbins EE, Kangussu-Marcolino MM, Debnath A, White CV, Moser MS, DeRisi J, Gisselberg J, Yeh E, Wang SC, Company AH, Monti L, Caffrey CR, Huston CD, Wang B, Singh U. Identification of anisomycin, prodigiosin and obatoclax as compounds with broad-spectrum anti-parasitic activity. PLoS Negl Trop Dis 2020; 14:e0008150. [PMID: 32196500 PMCID: PMC7112225 DOI: 10.1371/journal.pntd.0008150] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 04/01/2020] [Accepted: 02/18/2020] [Indexed: 01/20/2023] Open
Abstract
Parasitic infections are a major source of human suffering, mortality, and economic loss, but drug development for these diseases has been stymied by the significant expense involved in bringing a drug though clinical trials and to market. Identification of single compounds active against multiple parasitic pathogens could improve the economic incentives for drug development as well as simplifying treatment regimens. We recently performed a screen of repurposed compounds against the protozoan parasite Entamoeba histolytica, causative agent of amebic dysentery, and identified four compounds (anisomycin, prodigiosin, obatoclax and nithiamide) with low micromolar potency and drug-like properties. Here, we extend our investigation of these drugs. We assayed the speed of killing of E. histolytica trophozoites and found that all four have more rapid action than the current drug of choice, metronidazole. We further established a multi-institute collaboration to determine whether these compounds may have efficacy against other parasites and opportunistic pathogens. We found that anisomycin, prodigiosin and obatoclax all have broad-spectrum antiparasitic activity in vitro, including activity against schistosomes, T. brucei, and apicomplexan parasites. In several cases, the drugs were found to have significant improvements over existing drugs. For instance, both obatoclax and prodigiosin were more efficacious at inhibiting the juvenile form of Schistosoma than the current standard of care, praziquantel. Additionally, low micromolar potencies were observed against pathogenic free-living amebae (Naegleria fowleri, Balamuthia mandrillaris and Acanthamoeba castellanii), which cause CNS infection and for which there are currently no reliable treatments. These results, combined with the previous human use of three of these drugs (obatoclax, anisomycin and nithiamide), support the idea that these compounds could serve as the basis for the development of broad-spectrum anti-parasitic drugs.
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Affiliation(s)
- Gretchen Ehrenkaufer
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University, Stanford, CA, United States of America
| | - Pengyang Li
- Department of Bioengineering, Stanford University, Stanford, CA, United States of America
| | - Erin E. Stebbins
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont, United States of America
| | - Monica M. Kangussu-Marcolino
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University, Stanford, CA, United States of America
| | - Anjan Debnath
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, United States of America
| | - Corin V. White
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, California, United States of America
| | - Matthew S. Moser
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, California, United States of America
| | - Joseph DeRisi
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, California, United States of America
| | - Jolyn Gisselberg
- Department of Biochemistry, Stanford Medical School, Stanford University, Stanford, CA, United States of America
| | - Ellen Yeh
- Department of Biochemistry, Stanford Medical School, Stanford University, Stanford, CA, United States of America
- Department of Microbiology and Immunology, Stanford University, Stanford, CA, United States of America
- Department of Pathology, Stanford University, Stanford, CA, United States of America
| | - Steven C. Wang
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, United States of America
| | - Ana Hervella Company
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, United States of America
| | - Ludovica Monti
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, United States of America
| | - Conor R. Caffrey
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, United States of America
| | - Christopher D. Huston
- Department of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont, United States of America
| | - Bo Wang
- Department of Bioengineering, Stanford University, Stanford, CA, United States of America
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, United States of America
| | - Upinder Singh
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University, Stanford, CA, United States of America
- Department of Microbiology and Immunology, Stanford University, Stanford, CA, United States of America
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Niculescu VF. aCLS cancers: Genomic and epigenetic changes transform the cell of origin of cancer into a tumorigenic pathogen of unicellular organization and lifestyle. Gene 2020; 726:144174. [DOI: 10.1016/j.gene.2019.144174] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 10/13/2019] [Accepted: 10/15/2019] [Indexed: 02/08/2023]
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Functional Assessment of 2,177 U.S. and International Drugs Identifies the Quinoline Nitroxoline as a Potent Amoebicidal Agent against the Pathogen Balamuthia mandrillaris. mBio 2018; 9:mBio.02051-18. [PMID: 30377287 PMCID: PMC6212833 DOI: 10.1128/mbio.02051-18] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Balamuthia mandrillaris is responsible for hundreds of reported cases of amoebic encephalitis, the majority of which have been fatal. Despite being an exceptionally deadly pathogen, B. mandrillaris is understudied, leaving many open questions regarding epidemiology, diagnosis, and treatment. Due to the lack of effective drugs to fight B. mandrillaris infections, mortality rates remain high even for patients receiving intensive care. This report addresses the need for new treatment options through a drug repurposing screen to identify novel B. mandrillaris inhibitors. The most promising candidate identified was the quinoline antibiotic nitroxoline, which has a long history of safe use in humans. We show that nitroxoline kills B. mandrillaris at pharmacologically relevant concentrations and exhibits greater potency and selectivity than drugs commonly used in the current standard of care. The findings that we present demonstrate the potential of nitroxoline to be an important new tool in the treatment of life-threatening B. mandrillaris infections. Balamuthia mandrillaris is a pathogenic free-living amoeba that causes a rare but almost always fatal infection of the central nervous system called granulomatous amoebic encephalitis (GAE). Two distinct forms of B. mandrillaris—a proliferative trophozoite form and a nonproliferative cyst form, which is highly resistant to harsh physical and chemical conditions—have been isolated from environmental samples worldwide and are both observed in infected tissue. Patients suffering from GAE are typically treated with aggressive and prolonged multidrug regimens that often include the antimicrobial agents miltefosine and pentamidine isethionate. However, survival rates remain low, and studies evaluating the susceptibility of B. mandrillaris to these compounds and other potential therapeutics are limited. To address the need for more-effective treatments, we screened 2,177 clinically approved compounds for in vitro activity against B. mandrillaris. The quinoline antibiotic nitroxoline (8-hydroxy-5-nitroquinoline), which has safely been used in humans to treat urinary tract infections, was identified as a lead compound. We show that nitroxoline inhibits both trophozoites and cysts at low micromolar concentrations, which are within a pharmacologically relevant range. We compared the in vitro efficacy of nitroxoline to that of drugs currently used in the standard of care for GAE and found that nitroxoline is the most potent and selective inhibitor of B. mandrillaris tested. Furthermore, we demonstrate that nitroxoline prevents B. mandrillaris-mediated destruction of host cells in cultured fibroblast and primary brain explant models also at pharmacologically relevant concentrations. Taken together, our findings indicate that nitroxoline is a promising candidate for repurposing as a novel treatment of B. mandrillaris infections.
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Siddiqui R, Abjani F, Yeo CI, Tiekink ERT, Khan NA. The effects of phosphanegold(I) thiolates on the biological properties of Acanthamoeba castellanii belonging to the T4 genotype. J Negat Results Biomed 2017; 16:6. [PMID: 28366172 PMCID: PMC5376697 DOI: 10.1186/s12952-017-0070-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 02/09/2017] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Gold compounds have shown promise in the treatment of non-communicable diseases such as rheumatoid arthritis and cancer, and are considered of value as anti-microbial agents against Gram-negative and Gram-positive bacteria, and have anti-parasitic properties against Schistosoma mansoni, Trypanosoma brucei, Plasmodium falciparum, Leishmania infantinum, Giardia lamblia, and Entamoeba histolytica. They are known to affect enzymatic activities that are required for the cellular respiration processes. METHODS Anti-amoebic effects of phosphanegold(I) thiolates were tested against clinical isolate of A. castellanii belonging to the T4 genotype by employing viability assays, growth inhibition assays, encystation assays, excystation assays, and zymographic assays. RESULTS The treatment of A. castellanii with the phosphanegold(I) thiolates tested (i) had no effect on the viability of A. castellanii as determined by Trypan blue exclusion test, (ii) did not affect amoebae growth using PYG growth medium, (iii) did not inhibit cellular differentiation, and (iv) had no effect on the extracellular proteolytic activities of A. castellanii. CONCLUSION Being free-living amoeba, A. castellanii is a versatile respirator and possesses respiratory mechanisms that adapt to various aerobic and anaerobic environments to avoid toxic threats and adverse conditions. For the first time, our findings showed that A. castellanii exhibits resistance to the toxic effects of gold compounds and could prove to be an attractive model to study mechanisms of metal resistance in eukaryotic cells.
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Affiliation(s)
- Ruqaiyyah Siddiqui
- Department of Biological Sciences, Faculty of Science and Technology, Sunway University, 47500 Bandar Sunway, Selangor, Malaysia
| | - Farhat Abjani
- Department of Biological Sciences, Faculty of Science and Technology, Sunway University, 47500 Bandar Sunway, Selangor, Malaysia
| | - Chien Ing Yeo
- Research Centre for Crystalline Materials, Sunway University, 47500 Bandar Sunway, Selangor, Malaysia
| | - Edward R T Tiekink
- Research Centre for Crystalline Materials, Sunway University, 47500 Bandar Sunway, Selangor, Malaysia
| | - Naveed Ahmed Khan
- Department of Biological Sciences, Faculty of Science and Technology, Sunway University, 47500 Bandar Sunway, Selangor, Malaysia.
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Siddiqui R, Khan NA. Balamuthia mandrillaris: Morphology, biology, and virulence. Trop Parasitol 2015; 5:15-22. [PMID: 25709948 PMCID: PMC4326988 DOI: 10.4103/2229-5070.149888] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 01/22/2015] [Indexed: 11/04/2022] Open
Abstract
Balamuthia mandrillaris is a protist pathogen that can cause encephalitis with a fatality rate of >95%. This is due to our incomplete understanding of the pathogenesis and pathophysiology of B. mandrillaris encephalitis. B. mandrillaris has two stages in its life cycle, an active trophozoite stage during which it divides mitotically. However, under unfavorable conditions, the trophozoite transforms into a dormant cyst stage. A major concern during the course of therapy is that B. mandrillaris can transform into cysts. Cysts are highly resistant to physical and chemical conditions and present a problem in successful antimicrobial chemotherapy. Several lines of evidence suggest that B. mandrillaris encephalitis develops as a result of hematogenous spread, but it is unclear how circulating amoebae enter the central nervous system and cause inflammation, blood-brain barrier disruption, and neuronal injury. Recent studies have identified several parasite-host determinants for B. mandrillaris translocation of the blood-brain barrier, and host inflammatory markers that may be associated with neuronal injury. These determinants may provide important targets for the prevention and treatment of this devastating infection. Here, we present a brief overview of the current understanding of the morphology, biology, pathogenesis, and pathophysiology of B. mandrillaris encephalitis.
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Affiliation(s)
- Ruqaiyyah Siddiqui
- Department of Biological and Biomedical Sciences, Aga Khan University, Karachi, Pakistan
| | - Naveed Ahmed Khan
- Department of Biological and Biomedical Sciences, Aga Khan University, Karachi, Pakistan
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Abedkhojasteh H, Niyyati M, Rezaei S, Mohebali M, Farnia S, Kazemi-Rad E, Roozafzoon R, Sianati H, Rezaeian M, Heidari M. Identifying differentially expressed genes in trophozoites and cysts of Acanthamoeba T4 genotype: Implications for developing new treatments for Acanthamoeba keratitis. Eur J Protistol 2015; 51:34-41. [DOI: 10.1016/j.ejop.2014.10.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 10/02/2014] [Accepted: 10/04/2014] [Indexed: 12/23/2022]
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Lakhundi S, Khan NA, Siddiqui R. The effect of environmental and physiological conditions on excystation of Acanthamoeba castellanii belonging to the T4 genotype. Parasitol Res 2014; 113:2809-16. [DOI: 10.1007/s00436-014-3941-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 05/01/2014] [Indexed: 11/28/2022]
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Actin, RhoA, and Rab11 participation during encystment in Entamoeba invadens. BIOMED RESEARCH INTERNATIONAL 2013; 2013:919345. [PMID: 24175308 PMCID: PMC3794519 DOI: 10.1155/2013/919345] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Revised: 08/09/2013] [Accepted: 08/09/2013] [Indexed: 11/17/2022]
Abstract
In the genus Entamoeba, actin reorganization is necessary for cyst differentiation; however, its role is still unknown. The aim of this work was to investigate the role of actin and encystation-related proteins during Entamoeba invadens encystation. Studied proteins were actin, RhoA, a small GTPase involved through its effectors in the rearrangement of the actin cytoskeleton; Rab11, a protein involved in the transport of encystation vesicles; and enolase, as an encystment vesicles marker. Results showed a high level of polymerized actin accompanied by increased levels of RhoA-GTP during cell rounding and loss of vacuoles. Cytochalasin D, an actin polymerization inhibitor, and Y27632, an inhibitor of RhoA activity, reduced encystment in 80%. These inhibitors also blocked cell rounding, disposal of vacuoles, and the proper formation of the cysts wall. At later times, F-actin and Rab11 colocalized with enolase, suggesting that Rab11 could participate in the transport of the cyst wall components through the F-actin cytoskeleton. These results suggest that actin cytoskeleton rearrangement is playing a decisive role in determining cell morphology changes and helping with the transport of cell wall components to the cell surface during encystment of E. invadens.
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Lorenzo-Morales J, Cabello-Vílchez AM, Martín-Navarro CM, Martínez-Carretero E, Piñero JE, Valladares B. Is Balamuthia mandrillaris a public health concern worldwide? Trends Parasitol 2013; 29:483-8. [PMID: 23988231 DOI: 10.1016/j.pt.2013.07.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 07/25/2013] [Accepted: 07/26/2013] [Indexed: 10/26/2022]
Abstract
Balamuthia mandrillaris is an opportunistic, free-living amoeba that can cause skin lesions and the typically fatal Balamuthia amoebic encephalitis (BAE) both in immunocompromised and immunocompetent individuals. Available data for BAE cases indicate that this disease is difficult to detect because knowledge of predisposing factors is lacking, causing a challenge for diagnosing BAE. The number of reported BAE cases is increasing worldwide, and this is a major concern because little is known about the pathogen, no standardized detection tools are available, and most of the treatments are almost empirical. The recently reported cases, novel diagnostics tools, and successful therapeutic approaches against BAE infections are reviewed here.
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Affiliation(s)
- Jacob Lorenzo-Morales
- University Institute of Tropical Diseases and Public Health of The Canary Islands, University of La Laguna, Avenida Astrofísico Francisco Sánchez SN, 38203 La Laguna, Tenerife, Canary Islands, Spain.
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13
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Jeelani G, Sato D, Husain A, Escueta-de Cadiz A, Sugimoto M, Soga T, Suematsu M, Nozaki T. Metabolic profiling of the protozoan parasite Entamoeba invadens revealed activation of unpredicted pathway during encystation. PLoS One 2012; 7:e37740. [PMID: 22662204 PMCID: PMC3360610 DOI: 10.1371/journal.pone.0037740] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 04/23/2012] [Indexed: 01/22/2023] Open
Abstract
Encystation, which is cellular differentiation from the motile, proliferative, labile trophozoite form to the dormant, resistant cyst form, is a crucial process found in parasitic and free-living protozoa such as Entamoeba, Giardia, Acanthamoeba, and Balamuthia. Since encystation is an essential process to deal with the adverse external environmental changes during the life cycle, and often integral to the transmission of the diseases, biochemical understanding of the process potentially provides useful measures against the infections caused by this group of protozoa. In this study, we investigated metabolic and transcriptomic changes that occur during encystation in Entamoeba invadens, the reptilian sibling of mammal-infecting E. histolytica, using capillary electrophoresis-tandem mass spectrometry-based metabolite profiling and DNA microarray-based expression profiling. As the encystation progressed, the levels of majority of metabolites involved in glycolysis and nucleotides drastically decreased, indicating energy generation is ceased. Furthermore, the flux of glycolysis was redirected toward chitin wall biosynthesis. We found remarkable temporal increases in biogenic amines such as isoamylamine, isobutylamine, and cadaverine, during the early period of encystation, when the trophozoites form large multicellular aggregates (precyst). We also found remarkable induction of γ-aminobutyric acid (GABA) during encystation. This study has unveiled for the first time the dynamics of the transcriptional and metabolic regulatory networks during encystation, and should help in better understanding of the process in pathogenic eukaryotes, and further development of measures controlling infections they cause.
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Affiliation(s)
- Ghulam Jeelani
- Department of Parasitology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
- Department of Biochemistry and Integrative Medical Biology, School of Medicine, Keio University, Shinjuku, Tokyo, Japan
| | - Dan Sato
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, Japan
| | - Afzal Husain
- Department of Parasitology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
- Department of Parasitology, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Aleyla Escueta-de Cadiz
- Department of Parasitology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
- Department of Parasitology, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Masahiro Sugimoto
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, Japan
| | - Tomoyoshi Soga
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, Japan
| | - Makoto Suematsu
- Department of Biochemistry and Integrative Medical Biology, School of Medicine, Keio University, Shinjuku, Tokyo, Japan
| | - Tomoyoshi Nozaki
- Department of Parasitology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
- * E-mail:
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Cellular, biochemical, and molecular changes during encystment of free-living amoebae. EUKARYOTIC CELL 2012; 11:382-7. [PMID: 22366126 DOI: 10.1128/ec.05301-11] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Free-living amoebae are protozoa found in soil and water. Among them, some are pathogenic and many have been described as potential reservoirs of pathogenic bacteria. Their cell cycle is divided into at least two forms, the trophozoite and the cyst, and the differentiation process is named encystment. As cysts are more resistant to disinfection treatments than trophozoites, many studies focused on encystment, but until recently, little was known about cellular, biochemical, and molecular modifications operating during this process. Important signals and signaling pathways at play during encystment, as well as cell responses at the molecular level, have been described. This review summarizes our knowledge and focuses on new findings.
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