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Amsri A, Pruksaphon K, Thammasit P, Nosanchuk JD, Youngchim S. Adaptation to an amoeba host drives selection of virulence-associated traits and genetic variation in saprotrophic Candida albicans. Front Cell Infect Microbiol 2024; 14:1367656. [PMID: 38550616 PMCID: PMC10976851 DOI: 10.3389/fcimb.2024.1367656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 02/27/2024] [Indexed: 04/02/2024] Open
Abstract
Amoebae are micropredators that play an important role in controlling fungal populations in ecosystems. However, the interaction between fungi and their amoebic predators suggests that the pressure from predatory selection can significantly influence the development of fungal virulence and evolutionary processes. Thus, the purpose of this study was to investigate the adaptation of saprotrophic Candida albicans strains during their interactions with Acanthamoeba castellanii. We conducted a comprehensive analysis of survival after co-culture by colony counting of the yeast cells and examining yeast cell phenotypic and genetic characteristics. Our results indicated that exposure to amoebae enhanced the survival capacity of environmental C. albicans and induced visible morphological alterations in C. albicans, particularly by an increase in filamentation. These observed phenotypic changes were closely related to concurrent genetic variations. Notably, mutations in genes encoding transcriptional repressors (TUP1 and SSN6), recognized for their negative regulation of filamentous growth, were exclusively identified in amoeba-passaged isolates, and absent in unexposed isolates. Furthermore, these adaptations increased the exposed isolates' fitness against various stressors, simultaneously enhancing virulence factors and demonstrating an increased ability to invade A549 lung human epithelial cells. These observations indicate that the sustained survival of C. albicans under ongoing amoebic predation involved a key role of mutation events in microevolution to modulate the ability of these isolates to change phenotype and increase their virulence factors, demonstrating an enhanced potential to survive in diverse environmental niches.
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Affiliation(s)
- Artid Amsri
- Office of Research Administration, Chiang Mai University, Chiang Mai, Thailand
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Kritsada Pruksaphon
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat, Thailand
- Center of Excellence Research for Melioidosis and Microorganisms (CERMM), Walailak University, Nakhon Si Thammarat, Thailand
| | - Patcharin Thammasit
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Joshua D. Nosanchuk
- Department of Medicine (Division of Infectious Diseases), Department of Microbiology and Immunology, Albert Einstein College of Medicine, New York, NY, United States
| | - Sirida Youngchim
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
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Ferreira MDS, Gonçalves DDS, Mendoza SR, de Oliveira GA, Pontes B, la Noval CRD, Honorato L, Ramos LFC, Nogueira FCS, Domont GB, Casadevall A, Nimrichter L, Peralta JM, Guimaraes AJ. β-1,3-Glucan recognition by Acanthamoeba castellanii as a putative mechanism of amoeba-fungal interactions. Appl Environ Microbiol 2024; 90:e0173623. [PMID: 38259076 PMCID: PMC10880599 DOI: 10.1128/aem.01736-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 12/15/2023] [Indexed: 01/24/2024] Open
Abstract
In this study, we conducted an in-depth analysis to characterize potential Acanthamoeba castellanii (Ac) proteins capable of recognizing fungal β-1,3-glucans. Ac specifically anchors curdlan or laminarin, indicating the presence of surface β-1,3-glucan-binding molecules. Using optical tweezers, strong adhesion of laminarin- or curdlan-coated beads to Ac was observed, highlighting their adhesive properties compared to controls (characteristic time τ of 46.9 and 43.9 s, respectively). Furthermore, Histoplasma capsulatum (Hc) G217B, possessing a β-1,3-glucan outer layer, showed significant adhesion to Ac compared to a Hc G186 strain with an α-1,3-glucan outer layer (τ of 5.3 s vs τ 83.6 s). The addition of soluble β-1,3-glucan substantially inhibited this adhesion, indicating the involvement of β-1,3-glucan recognition. Biotinylated β-1,3-glucan-binding proteins from Ac exhibited higher binding to Hc G217B, suggesting distinct recognition mechanisms for laminarin and curdlan, akin to macrophages. These observations hinted at the β-1,3-glucan recognition pathway's role in fungal entrance and survival within phagocytes, supported by decreased fungal viability upon laminarin or curdlan addition in both phagocytes. Proteomic analysis identified several Ac proteins capable of binding β-1,3-glucans, including those with lectin/glucanase superfamily domains, carbohydrate-binding domains, and glycosyl transferase and glycosyl hydrolase domains. Notably, some identified proteins were overexpressed upon curdlan/laminarin challenge and also demonstrated high affinity to β-1,3-glucans. These findings underscore the complexity of binding via β-1,3-glucan and suggest the existence of alternative fungal recognition pathways in Ac.IMPORTANCEAcanthamoeba castellanii (Ac) and macrophages both exhibit the remarkable ability to phagocytose various extracellular microorganisms in their respective environments. While substantial knowledge exists on this phenomenon for macrophages, the understanding of Ac's phagocytic mechanisms remains elusive. Recently, our group identified mannose-binding receptors on the surface of Ac that exhibit the capacity to bind/recognize fungi. However, the process was not entirely inhibited by soluble mannose, suggesting the possibility of other interactions. Herein, we describe the mechanism of β-1,3-glucan binding by A. castellanii and its role in fungal phagocytosis and survival within trophozoites, also using macrophages as a model for comparison, as they possess a well-established mechanism involving the Dectin-1 receptor for β-1,3-glucan recognition. These shed light on a potential parallel evolution of pathways involved in the recognition of fungal surface polysaccharides.
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Affiliation(s)
- Marina da Silva Ferreira
- Laboratório de Bioquímica e Imunologia das Micoses, Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Universidade Federal Fluminense, Niterói, Rio de Janeiro, Brazil
- Programa de Pós-Graduação em Imunologia e Inflamação, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Niterói, Rio de Janeiro, Brazil
| | - Diego de Souza Gonçalves
- Programa de Pós-Graduação em Doenças Infecciosas e Parasitárias, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Niterói, Rio de Janeiro, Brazil
| | - Susana Ruiz Mendoza
- Laboratório de Bioquímica e Imunologia das Micoses, Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Universidade Federal Fluminense, Niterói, Rio de Janeiro, Brazil
- Programa de Pós-Graduação em Imunologia e Inflamação, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Niterói, Rio de Janeiro, Brazil
| | - Gabriel Afonso de Oliveira
- Laboratório de Bioquímica e Imunologia das Micoses, Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Universidade Federal Fluminense, Niterói, Rio de Janeiro, Brazil
| | - Bruno Pontes
- Instituto de Ciências Biomédicas e Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Niterói, Rio de Janeiro, Brazil
| | - Claudia Rodríguez-de la Noval
- Laboratório de Bioquímica e Imunologia das Micoses, Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Universidade Federal Fluminense, Niterói, Rio de Janeiro, Brazil
- Programa de Pós-Graduação em Doenças Infecciosas e Parasitárias, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Niterói, Rio de Janeiro, Brazil
| | - Leandro Honorato
- Laboratório de Glicobiologia de Eucariotos, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Niterói, Rio de Janeiro, Brazil
| | - Luis Felipe Costa Ramos
- Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro, Niterói, Rio de Janeiro, Brazil
| | - Fábio C. S. Nogueira
- Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro, Niterói, Rio de Janeiro, Brazil
| | - Gilberto B. Domont
- Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro, Niterói, Rio de Janeiro, Brazil
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Leonardo Nimrichter
- Programa de Pós-Graduação em Imunologia e Inflamação, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Niterói, Rio de Janeiro, Brazil
- Laboratório de Glicobiologia de Eucariotos, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Niterói, Rio de Janeiro, Brazil
- Rede Micologia RJ - Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), Niterói, Rio de Janeiro, Brazil
| | - Jose Mauro Peralta
- Programa de Pós-Graduação em Doenças Infecciosas e Parasitárias, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Niterói, Rio de Janeiro, Brazil
| | - Allan J. Guimaraes
- Laboratório de Bioquímica e Imunologia das Micoses, Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Universidade Federal Fluminense, Niterói, Rio de Janeiro, Brazil
- Programa de Pós-Graduação em Imunologia e Inflamação, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Niterói, Rio de Janeiro, Brazil
- Rede Micologia RJ - Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), Niterói, Rio de Janeiro, Brazil
- Pós-Graduação em Microbiologia e Parasitologia Aplicadas, Instituto Biomédico, Universidade Federal Fluminense, Niterói, Rio de Janeiro, Brazil
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Akbar N, Siddiqui R, El-Gamal MI, Zaraei SO, Saeed BQ, Alawfi BS, Khan NA. Potential anti-amoebic activity of sulfonate- and sulfamate-containing carboxamide derivatives against pathogenic Acanthamoeba castellanii belonging to the genotype T4. Parasitol Int 2024; 98:102814. [PMID: 37806551 DOI: 10.1016/j.parint.2023.102814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 09/28/2023] [Accepted: 10/05/2023] [Indexed: 10/10/2023]
Abstract
Acanthamoeba are ubiquitously distributed in the environment and can cause infection of the central nervous system as well a sight-threatening eye infection. Herein, the potential anti-amoebic activity of a series of sulfonate/sulfamate derivatives against pathogenic A. castellanii was evaluated. These compounds were tested using several assays namely amoebicidal, adhesion, excystation, cytotoxic, and cytopathogenicity. Amoebicidal assays revealed that the selected compounds reduced amoebae viability significantly (P < 0.05), and exhibited IC50 values at two-digit micromolar concentrations. Sulfamate derivatives 1j & 1k inhibited 50% of amoebae at 30.65 μM and 27.21 μM, respectively. The tested compounds blocked amoebae binding to host cells as well as inhibited amoebae excystation. Notably, the selected derivatives exhibited minimal human cell cytotoxicity but reduced parasite-mediated host cell damage. Overall, our study showed that sulfamate derivatives 1j & 1k have anti-amoebic potential and offer a promising avenue in the development of potential anti-amoebic drug candidates.
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Affiliation(s)
- Noor Akbar
- Research Institute of Medical and Health Sciences, University of Sharjah, Sharjah 27272, United Arab Emirates; Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates
| | - Ruqaiyyah Siddiqui
- Microbiota Research Center, Istinye University, Istanbul 34010, Turkey; College of Arts and Sciences, American University of Sharjah, Sharjah 26666, United Arab Emirates
| | - Mohammed I El-Gamal
- Research Institute of Medical and Health Sciences, University of Sharjah, Sharjah 27272, United Arab Emirates; Department of Medicinal Chemistry, College of Pharmacy, University of Sharjah, Sharjah 27272, United Arab Emirates; Department of Medicinal Chemistry, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt.
| | - Seyed-Omar Zaraei
- Research Institute of Medical and Health Sciences, University of Sharjah, Sharjah 27272, United Arab Emirates
| | - Balsam Qubais Saeed
- Research Institute of Medical and Health Sciences, University of Sharjah, Sharjah 27272, United Arab Emirates; Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates
| | - Bader Saleem Alawfi
- Department of Medical Laboratories Technology, College of Applied Medical Sciences, Taibah University, Madinah 42353, Saudi Arabia
| | - Naveed Ahmed Khan
- Microbiota Research Center, Istinye University, Istanbul 34010, Turkey; Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates.
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Scheckhuber CQ, Damián Ferrara R, Gómez-Montalvo J, Maciver SK, de Obeso Fernández Del Valle A. Oxidase enzyme genes are differentially expressed during Acanthamoeba castellanii encystment. Parasitol Res 2024; 123:116. [PMID: 38289423 DOI: 10.1007/s00436-024-08138-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 01/22/2024] [Indexed: 02/01/2024]
Abstract
Acanthamoeba castellanii, a ubiquitous protozoan, is responsible for significant diseases such as Acanthamoeba keratitis and granulomatous amoebic encephalitis. A crucial survival strategy of A. castellanii involves the formation of highly resistant cysts during adverse conditions. This study delves into the cellular processes underpinning encystment, focusing on gene expression changes related to reactive oxygen species (ROS) balance, with a particular emphasis on mitochondrial processes. Our findings reveal a dynamic response within the mitochondria during encystment, with the downregulation of key enzymes involved in oxidative phosphorylation (COX, AOX, and NADHalt) during the initial 48 h, followed by their overexpression at 72 h. This orchestrated response likely creates a pro-oxidative environment, facilitating encystment. Analysis of other ROS processing enzymes across the cell reveals differential expression patterns. Notably, antioxidant enzymes, such as catalases, glutaredoxins, glutathione S-transferases, peroxiredoxins, and thioredoxins, mirror the mitochondrial trend of downregulation followed by upregulation. Additionally, glycolysis and gluconeogenesis are downregulated during the early stages in order to potentially balance the metabolic requirement of the cyst. Our study underscores the importance of ROS regulation in Acanthamoeba encystment. Understanding these mechanisms offers insights into infection control and identifies potential therapeutic targets. This work contributes to unraveling the complex biology of A. castellanii and may aid in combatting Acanthamoeba-related infections. Further research into ROS and oxidase enzymes is warranted, given the organism's remarkable respiratory versatility.
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Affiliation(s)
- Christian Q Scheckhuber
- Tecnologico de Monterrey, Escuela de Ingeniería y Ciencias, Ave. Eugenio Garza Sada 2501, 64849, Monterrey, N.L, Mexico
| | - Rebeca Damián Ferrara
- Tecnologico de Monterrey, Escuela de Ingeniería y Ciencias, Ave. Eugenio Garza Sada 2501, 64849, Monterrey, N.L, Mexico
| | - Jesús Gómez-Montalvo
- Tecnologico de Monterrey, Escuela de Ingeniería y Ciencias, Ave. Eugenio Garza Sada 2501, 64849, Monterrey, N.L, Mexico
| | - Sutherland K Maciver
- Centre for Discovery Brain Sciences, Edinburgh Medical School, Biomedical Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, Scotland, UK
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Chen CH, Liao CC, Wang YJ, Huang FC, Lin WC. A. castellanii and P. aeruginosa mutually exacerbate damage to corneal cells during coinfection. Microbiol Spectr 2024; 12:e0268323. [PMID: 38095463 PMCID: PMC10783079 DOI: 10.1128/spectrum.02683-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 10/31/2023] [Indexed: 01/13/2024] Open
Abstract
IMPORTANCE At the National Cheng Kung University Hospital, numerous cases of amoebic keratitis had been identified with concurrent bacterial infections. Among these bacterial coinfections, Pseudomonas aeruginosa accounted for 50% of the reported cases. However, the impact of pathogenic bacteria on amoeba-induced corneal damage remains unclear. In our study, we successfully demonstrated that P. aeruginosa accumulated on the Acanthamoeba castellanii surface and caused more severe corneal damage. We also indicated that the exposure of P. aeruginosa to amoeba-soluble antigens enhanced its adhesion ability, promoted biofilm formation, and led to more severe corneal cell damage. These findings significantly contributed to our understanding of the risk associated with P. aeruginosa coinfection in the progression of amoeba keratitis.
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Affiliation(s)
- Chun-Hsien Chen
- Department of Parasitology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Chen-Chieh Liao
- Department of Parasitology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yu-Jen Wang
- Department of Parasitology, School of Medicine, China Medical University, Taichung, Taiwan
| | - Fu-Chin Huang
- Department of Ophthalmology, College of Medicine, National Cheng Kung University Hospital, National Cheng Kung University, Tainan, Taiwan
| | - Wei-Chen Lin
- Department of Parasitology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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Thomas L, Khan NA, Siddiqui R, Alawfi BS, Lloyd D. Cell death of Acanthamoeba castellanii following exposure to antimicrobial agents commonly included in contact lens disinfecting solutions. Parasitol Res 2023; 123:16. [PMID: 38060008 DOI: 10.1007/s00436-023-08061-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 10/27/2023] [Indexed: 12/08/2023]
Abstract
Several antimicrobial agents are commonly included in contact lens disinfectant solutions including chlorhexidine diacetate (CHX), polyhexamethylene biguanide (PHMB) or myristamidopropyl dimethylamine (MAPD); however, their mode of action, i.e. necrosis versus apoptosis is incompletely understood. Here, we determined whether a mechanism of cell death resembling that of apoptosis was present in Acanthamoeba castellanii of the T4 genotype (NEFF) following exposure to the aforementioned antimicrobials using the anticoagulant annexin V that undergoes rapid high affinity binding to phosphatidylserine in the presence of calcium, making it a sensitive probe for phosphatidylserine exposure. The results revealed that under the conditions employed in this study, an apoptotic pathway of cell death in this organism at the tested conditions does not occur. Our findings suggest that necrosis is the likely mode of action; however, future mechanistic studies should be accomplished in additional experimental conditions to further comprehend the molecular mechanisms of cell death in Acanthamoeba.
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Affiliation(s)
- Louise Thomas
- Microbiology Research, School of Biosciences, Cardiff University, P. O. Box 915, Cardiff, CF10 3AX, UK
| | - Naveed Ahmed Khan
- Microbiota Research Center, Istinye University, 34010, Istanbul, Turkey.
| | - Ruqaiyyah Siddiqui
- Microbiota Research Center, Istinye University, 34010, Istanbul, Turkey
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University Edinburgh, Edinburgh, EH14 4AS, UK
| | - Bader S Alawfi
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Taibah University, Madinah, 42353, Saudi Arabia
| | - David Lloyd
- Microbiology Research, School of Biosciences, Cardiff University, P. O. Box 915, Cardiff, CF10 3AX, UK.
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Hoque MM, Noorian P, Espinoza-Vergara G, Adhikary S, To J, Rice SA, McDougald D. Increased iron utilization and oxidative stress tolerance in a Vibrio cholerae flrA mutant confers resistance to amoeba predation. Appl Environ Microbiol 2023; 89:e0109523. [PMID: 37882527 PMCID: PMC10686080 DOI: 10.1128/aem.01095-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 09/15/2023] [Indexed: 10/27/2023] Open
Abstract
IMPORTANCE Persistence of V. cholerae in the aquatic environment contributes to the fatal diarrheal disease cholera, which remains a global health burden. In the environment, bacteria face predation pressure by heterotrophic protists such as the free-living amoeba A. castellanii. This study explores how a mutant of V. cholerae adapts to acquire essential nutrients and survive predation. Here, we observed that up-regulation of iron acquisition genes and genes regulating resistance to oxidative stress enhances pathogen fitness. Our data show that V. cholerae can defend predation to overcome nutrient limitation and oxidative stress, resulting in an enhanced survival inside the protozoan hosts.
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Affiliation(s)
- M. Mozammel Hoque
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Sydney, NSW, Australia
| | - Parisa Noorian
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Sydney, NSW, Australia
| | - Gustavo Espinoza-Vergara
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Sydney, NSW, Australia
| | - Srijon Adhikary
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Sydney, NSW, Australia
| | - Joyce To
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Sydney, NSW, Australia
| | - Scott A. Rice
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Sydney, NSW, Australia
- CSIRO Animal, Food and Health Sciences, Westmead, NSW, Australia
| | - Diane McDougald
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Sydney, NSW, Australia
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Ahmed U, Ong SK, Tan KO, Khan KM, Khan NA, Siddiqui R, Alawfi BS, Anwar A. Alpha-Mangostin and its nano-conjugates induced programmed cell death in Acanthamoeba castellanii belonging to the T4 genotype. Int Microbiol 2023:10.1007/s10123-023-00450-1. [PMID: 38015290 DOI: 10.1007/s10123-023-00450-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 10/26/2023] [Accepted: 11/10/2023] [Indexed: 11/29/2023]
Abstract
Acanthamoeba are free living amoebae that are the causative agent of keratitis and granulomatous amoebic encephalitis. Alpha-Mangostin (AMS) is a significant xanthone; that demonstrates a wide range of biological activities. Here, the anti-amoebic activity of α-Mangostin and its silver nano conjugates (AMS-AgNPs) were evaluated against pathogenic A. castellanii trophozoites and cysts in vitro. Amoebicidal assays showed that both AMS and AMS-AgNPs inhibited the viability of A. castellanii dose-dependently, with an IC50 of 88.5 ± 2.04 and 20.2 ± 2.17 μM, respectively. Both formulations inhibited A. castellanii-mediated human keratinocyte cell cytopathogenicity. Functional assays showed that both samples caused apoptosis through the mitochondrial pathway and reduced mitochondrial membrane potential and ATP production, while increasing reactive oxygen species (ROS) and nicotinamide adenine dinucleotide phosphate (NADPH) cytochrome-c reductase in the cytosol. Whole transcriptome sequencing of A. castellanii showed the expression of 826 genes, with 447 genes being up-regulated and 379 genes being down-regulated post treatment. The Kyoto Encyclopedia of Genes and Genomes analysis showed that the majority of genes were linked to apoptosis, autophagy, RAP1, AGE-RAGE and oxytocin signalling pathways. Seven genes (PTEN, H3, ARIH1, SDR16C5, PFN, glnA GLUL, and SRX1) were identified as the most significant (Log2 (FC) value 4) for molecular mode of action in vitro. Future in vivo studies with AMS and nanoconjugates are needed to realize the clinical potential of this work.
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Affiliation(s)
- Usman Ahmed
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, 47500, Subang Jaya, Selangor, Malaysia
| | - Seng-Kai Ong
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, 47500, Subang Jaya, Selangor, Malaysia
| | - Kuan Onn Tan
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, 47500, Subang Jaya, Selangor, Malaysia
| | - Khalid Mohammed Khan
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Naveed Ahmed Khan
- Microbiota Research Center, Istinye University, Istanbul, 34010, Turkey.
| | - Ruqaiyyah Siddiqui
- Microbiota Research Center, Istinye University, Istanbul, 34010, Turkey
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Edinburgh, United Kingdom
| | - Bader Saleem Alawfi
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Taibah University, 42353, Madinah, Saudi Arabia
| | - Ayaz Anwar
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, 47500, Subang Jaya, Selangor, Malaysia.
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Ghosh S, Humera Khathun AH, Athulya GS, Vignesh P, Mathan L, Mudaraddi N, Narendran S, Lalitha P, Venkatesh Prajna N. Host cell-type and pathogen-specific immunomodulatory functions of macrophage migration inhibitory factor (MIF) in infectious keratitis. Exp Eye Res 2023; 236:109669. [PMID: 37774962 DOI: 10.1016/j.exer.2023.109669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 09/11/2023] [Accepted: 09/27/2023] [Indexed: 10/01/2023]
Abstract
Therapeutic management of inflammation in infectious keratitis (IK) requires new strategy and targets for selective immunomodulation. Targeting host cell-type specific inflammatory responses might be a viable strategy to curtail unnecessary inflammation and reduce tissue damage without affecting pathogen clearance. This study explores the possibility of pathogen and host cell-type dependent differences in the inflammatory pathways relevant in the pathogenesis of IK. Human corneal epithelial cell line (HCEC) and phorbol 12-myristate-13 acetate (PMA) differentiated THP-1 macrophage line were infected with either Aspergillus flavus conidia or Acanthamoeba castellanii trophozoites and the elicited inflammatory responses were studied in terms of gene expression and secretion of proinflammatory factors interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α) and an upstream inflammatory regulator and mediator protein-the Macrophage Migration Inhibitory Factor (MIF). Given the pleotropic mode of MIF function in diverse cell types relevant in many human diseases, we tested if MIF driven responses to infection is different in HCECs and THP-1 macrophages by studying its expression, secretion and involvement in inflammation by siRNA mediated knockdown. We also examined IK patient tear samples for MIF levels. Infection with A. flavus or A. castellanii induced IL-8 and TNF-α responses in HCECs and THP-1 macrophages but to different levels. Our preliminary human data showed that the level of secreted MIF protein was elevated in IK patient tear, however, MIF secretion by the two cell types were strikingly different in-vitro, under both normal and infected conditions. We found that HCECs released MIF constitutively, which was significantly inhibited with infection, whereas THP-1 macrophages were stimulated to release MIF during infection. MIF gene expression remained largely unaffected by infection in both the cell lines. Although MIF in HCECs appeared to be intracellularly captured during infection, MIF knockdown in HCECs associated with a partial reduction of the IL-8 and TNF-α expression produced by either of the pathogens, suggesting a pro-inflammatory role for MIF in HCECs, independent of its canonical cytokine like function. In contrast, MIF knockdown in THP-1 macrophages accompanied a dramatic increase in IL-8 and TNF-α expression during A. castellanii infection, while the responses to A. flavus infection remained unchanged. These data imply a host cell-type and pathogen specific distinction in the MIF- related inflammatory signaling and MIF as a potential selective immunomodulatory target in infectious keratitis.
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Affiliation(s)
- Swagata Ghosh
- Department of Microbiology, Aravind Medical Research Foundation, Madurai, India.
| | - A H Humera Khathun
- Department of Microbiology, Aravind Medical Research Foundation, Madurai, India
| | - G S Athulya
- Department of Microbiology, Aravind Medical Research Foundation, Madurai, India
| | - P Vignesh
- Department of Microbiology, Aravind Medical Research Foundation, Madurai, India
| | - L Mathan
- Department of Proteomics, Aravind Medical Research Foundation, Madurai, India
| | - Ninad Mudaraddi
- Department of Cornea and Refractive Surgery, Aravind Eye Hospital, Madurai, India
| | - Siddharth Narendran
- Department of Microbiology, Aravind Medical Research Foundation, Madurai, India; Aravind Eye Hospital, Coimbatore, India
| | - Prajna Lalitha
- Department of Ocular Microbiology, Aravind Eye Hospital, Madurai, India
| | - N Venkatesh Prajna
- Department of Cornea and Refractive Surgery, Aravind Eye Hospital, Madurai, India
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10
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Carvalho-Kelly LF, Freitas-Mesquita AL, Ferreira Pralon C, de Souza-Maciel E, Meyer-Fernandes JR. Identification and characterization of an ectophosphatase activity involved in Acanthamoeba castellanii adhesion to host cells. Eur J Protistol 2023; 91:126026. [PMID: 37871554 DOI: 10.1016/j.ejop.2023.126026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 10/06/2023] [Accepted: 10/11/2023] [Indexed: 10/25/2023]
Abstract
Acanthamoeba castellanii is a free-living amoeba and an opportunistic pathogen for humans that can cause encephalitis and, more commonly, Acanthamoeba keratitis. During its life cycle, A. castellanii may present as proliferative and infective trophozoites or resistant cysts. The adhesion of trophozoites to host cells is a key first step in the pathogenesis of infection. A major virulence protein of Acanthamoeba is a mannose-binding protein (MBP) that mediates the adhesion of amoebae to cell surfaces. Ectophosphatases are ecto-enzymes that can dephosphorylate extracellular substrates and have already been described in several microorganisms. Regarding their physiological roles, there is consistent evidence that ectophosphatase activities play an important role in parasite-host interactions. In the present work, we identified and biochemically characterized the ectophosphatase activity of A. castellanii. The ectophosphatase activity is acidic, stimulated by magnesium, cobalt and nickel, and presents the following apparent kinetic parameters: Km = 2.12 ± 0.54 mM p-NPP and Vmax = 26.12 ± 2.53 nmol p-NP × h-1 × 10-6 cells. We observed that sodium orthovanadate, ammonium molybdate, sodium fluoride, and inorganic phosphate are able to inhibit ectophosphatase activity. Comparing the two stages of the A. castellanii lifecycle, ectophosphatase activity is significantly higher in trophozoites than in cysts. The ectophosphatase activity is stimulated by mannose residues and is significantly increased when trophozoites interact with LLC-MK2 cells. The inhibition of ectophosphatase by pretreatment with sodium orthovanadate also inhibits the adhesion of trophozoites to epithelial cells. These results allow us to conclude that the ectophosphatase activity of A. castellanii is somehow important for the adhesion of trophozoites to their host cells. According to our data, we believe that the activation of MBP by mannose residues triggers the stimulation of ectophosphatase activity to facilitate the adhesion process.
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Affiliation(s)
| | | | - Clara Ferreira Pralon
- Instituto de Bioquímica Médica Leopoldo de Meis (IBqM), UFRJ, Rio de Janeiro, RJ, Brazil
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11
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Krela R, Poreba E, Lesniewicz K. Variations in the enzymatic activity of S1-type nucleases results from differences in their active site structures. Biochim Biophys Acta Gen Subj 2023; 1867:130424. [PMID: 37463618 DOI: 10.1016/j.bbagen.2023.130424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 05/27/2023] [Accepted: 07/02/2023] [Indexed: 07/20/2023]
Abstract
BACKGROUND S1-like nucleases are widespread enzymes commonly used in biotechnology and molecular biology. Although it is commonly believed that they are mainly Zn2+-dependent acidic enzymes, we have found that numerous members of this family deviate from this rule. Therefore, in this work, we decided to check how broad is the range of non‑zinc-dependent S1-like nucleases and what is the molecular basis of their activities. METHODS S1-like nucleases chosen for analysis were achieved through heterologous expression in appropriate eukaryotic hosts. To characterize nucleases' active-site properties, point mutations were introduced in selected positions. The enzymatic activities of wild-type and mutant nucleases were tested by in-gel nuclease activity assay. RESULTS We discovered that S1-like nucleases encoded by non-vascular plants and single-celled protozoa, like their higher plant homologues, exhibit a large variety of catalytic properties. We have shown that these individual properties are determined by specific non-conserved active site residues. CONCLUSIONS Our findings demonstrate that mutations that occur during evolution can significantly alter the catalytic properties of S1-like nucleases. As a result, different ions can compete for particular S1-type nucleases' active sites. This phenomenon undermines the existing classification of S1-like nucleases. GENERAL SIGNIFICANCE Our findings have numerous implications for applications and understanding the S1-like nucleases' biological functions. For example, new biotechnological applications should take into account their unexpected catalytic properties. Moreover, these results demonstrate that the trinuclear zinc-based model commonly used to characterize the catalytic activities of S1-like nucleases is insufficient to explain the actions of non‑zinc-dependent members of this family.
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Affiliation(s)
- Rafal Krela
- Department of Molecular and Cellular Biology, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University in Poznan, Umultowska St. 89, 61-614 Poznan, Poland; Biology Centre, Czech Academy of Sciences, Institute of Plant Molecular Biology, České Budějovice 370 05, Czech Republic.
| | - Elzbieta Poreba
- Department of Genetics, Institute of Experimental Biology, Adam Mickiewicz University in Poznan, Umultowska St. 89, 61-614 Poznan, Poland.
| | - Krzysztof Lesniewicz
- Department of Molecular and Cellular Biology, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University in Poznan, Umultowska St. 89, 61-614 Poznan, Poland.
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Bahrami S, Darvishi M, Zarei M, Sabaeian M, Henriquez FL. Sublethal Exposure to Plasma-Activated Water Influences the Morphological Characteristics, Phagocytic Ability, and Virulence of Acanthamoeba castellanii. Acta Parasitol 2023; 68:582-592. [PMID: 37338633 DOI: 10.1007/s11686-023-00691-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 05/29/2023] [Indexed: 06/21/2023]
Abstract
PURPOSE This study aimed to examine the ultrastructure, cytotoxicity, phagocytosis, and antioxidant responses of Acanthamoeba castellanii trophozoites exposed to sublethal plasma-activated water. METHODS Trophozoites were exposed to a sublethal treatment of PAW and compared to untreated viable trophozoites via adhesion assays on macrophage monolayers, osmo- and thermotolerance tests. Bacterial uptake was assessed in treated cells to evaluate their phagocytic characteristics. Oxidative stress biomarkers and antioxidant activities were compared in treated and untreated trophozoites. Finally, the expression of the mannose-binding protein (MBP), cysteine protease 3 (CP3), and serine endopeptidase (SEP) genes was determined in cells. RESULTS In PAW-treated trophozoites, cytopathic effects were more extensive and resulted in the detachment of macrophage monolayers. Treated trophozoites could not grow at high temperatures (43 °C). Moreover, they showed osmotolerance to 0.5 M D-mannitol but not to 1 M. Results demonstrated a higher bacterial uptake rate by PAW-treated trophozoites than untreated cells. Activities of superoxide dismutase and catalase and catalase were significantly greater in the treated trophozoites, and the glutathione and glutathione/glutathione disulfide were significantly lower in the PAW-treated cells. Exposure to PAW also significantly increased the malondialdehyde level and total antioxidant capacity. Treatment with PAW led to significantly higher expression of virulent genes like MBP, CP3, and SEP. CONCLUSION PAW is a double-edged sword against A. castellanii. PAW is an effective antiamoebic agent in proper usage, whereas its sublethal exposure may reduce its effectiveness and increase amoebas' pathogenicity. An agent's adequate concentration and exposure time are essential to achieve optimum results.
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Affiliation(s)
- Somayeh Bahrami
- Department of Parasitology, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
| | - Mojtaba Darvishi
- Department of Parasitology, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
| | - Mehdi Zarei
- Department of Food Hygiene, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
| | - Mohammad Sabaeian
- Department of Physics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
- Center for Research on Laser and Plasma, Shahid Chamran University of Ahvaz, Ahvaz, Iran
| | - Fiona L Henriquez
- Institute of Biomedical and Environmental Health Research, School of Health and Life Sciences, University of the West of Scotland (UWS), Paisley, PA1 2BE, Scotland, UK
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Hernández-Martínez D, Castro Pot E, Hernández Olmos P, Guzmán Hernández EA, Cobos DS, Villa Ramírez S, Villamar Duque TE, Durán Díaz Á, Omaña-Molina M. Acanthamoeba castellanii trophozoites that survive multipurpose solutions are able to adhere to cosmetic contact lenses, increasing the risk of infection. Heliyon 2023; 9:e19599. [PMID: 37809484 PMCID: PMC10558846 DOI: 10.1016/j.heliyon.2023.e19599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 08/14/2023] [Accepted: 08/28/2023] [Indexed: 10/10/2023] Open
Abstract
Amoebae of the genus Acanthamoeba are etiological agents of amoebic keratitis, for which up to now there is no treatment of choice and one of its main risk factors is the use of contact lenses, including cosmetic contact lenses. Recently there has been an increase in amoebic keratitis cases due to the use of cosmetic contact lenses. Therefore, having a solution for the care of lenses with an efficient disinfectant effect that prevents the adhesion of trophozoites to lenses becomes essential. This study was carried out to determine the effect of 8 multipurpose contact lenses care solutions on Acanthamoeba castellanii trophozoites viability, and the efficiency of two of them to prevent the trophozoites adherence onto two cosmetic contact lenses (Acuvue 2, approved by the US Food and Drug Administration, and Magic Eye CCL, not approved). After 3 h of interaction, only AO Sept Plus, OPTI FREE Replenish, Renu Plus, Bio True and Multiplus significantly reduced the number of viable trophozoites with respect to the control; at 6 h Renu Plus, and at 12 h Conta Soft Plus and Multiplus, maintained the inhibitory effect. Only Opti Free Pure Moist did not significantly reduce the number of viable trophozoites. Multiplus and Opti Free Pure Moist (selected for their greater and lesser antiamibic effect) significantly reduced trophozoite adherence to both lenses; however, Opti Free Pure Moist was more efficient, despite the fact that A. castellanii adhered similarly to both lenses. Our results show that in all the multipurpose solutions evaluated, hundreds of viable A. castellanii trophozoites remain after several hours of incubation. Therefore, storage of the lenses in their case with MPS maintains the potential risk of amoebic keratitis in, cosmetic contact lenses wearers. Moreover, the use of CCL, not approved by the FDA, can increase the risk factor for AK since its poor manufacture can favor the permanence of amoebae, in addition to being a risk for corneal integrity.
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Affiliation(s)
- Dolores Hernández-Martínez
- Carrera de Médico Cirujano, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Estado de México, Mexico
| | - Edson Castro Pot
- Carrera de Optometría, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Estado de México, Mexico
| | - Perla Hernández Olmos
- Carrera de Optometría, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Estado de México, Mexico
| | | | - David Segura Cobos
- Carrera de Médico Cirujano, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Estado de México, Mexico
| | - Sandra Villa Ramírez
- Carrera de Optometría, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Estado de México, Mexico
| | - Tomás Ernesto Villamar Duque
- Carrera de Biología, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Estado de México, Mexico
| | - Ángel Durán Díaz
- Carrera de Biología, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Estado de México, Mexico
| | - Maritza Omaña-Molina
- Carrera de Médico Cirujano, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Estado de México, Mexico
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Antos-Krzeminska N, Kicinska A, Nowak W, Jarmuszkiewicz W. Acanthamoeba castellanii Uncoupling Protein: A Complete Sequence, Activity, and Role in Response to Oxidative Stress. Int J Mol Sci 2023; 24:12501. [PMID: 37569876 PMCID: PMC10419851 DOI: 10.3390/ijms241512501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 08/01/2023] [Accepted: 08/04/2023] [Indexed: 08/13/2023] Open
Abstract
Uncoupling proteins (UCPs) are mitochondrial inner membrane transporters that mediate free-fatty-acid-induced, purine-nucleotide-inhibited proton leak into the mitochondrial matrix, thereby uncoupling respiratory substrate oxidation from ATP synthesis. The aim of this study was to provide functional evidence that the putative Acucp gene of the free-living protozoan amoeba, A. castellanii, encodes the mitochondrial protein with uncoupling activity characteristic of UCPs and to investigate its role during oxidative stress. We report the sequencing and cloning of a complete Acucp coding sequence, its phylogenetic analysis, and the heterologous expression of AcUCP in the S. cerevisiae strain InvSc1. Measurements of mitochondrial respiratory activity and membrane potential indicate that the heterologous expression of AcUCP causes AcUCP-mediated uncoupling activity. In addition, in a model of oxidative stress with increased reactive oxygen species levels (superoxide dismutase 1 knockout yeasts), AcUCP expression strongly promotes cell survival and growth. The level of superoxide anion radicals is greatly reduced in the ΔSOD1 strain expressing AcUCP. These results suggest that AcUCP targeted to yeast mitochondria causes uncoupling and may act as an antioxidant system. Phylogenetic analysis shows that the A. castellanii UCP diverges very early from other UCPs, but clearly locates within the UCP subfamily rather than among other mitochondrial anion carrier proteins.
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Affiliation(s)
- Nina Antos-Krzeminska
- Department of Bioenergetics, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 6, 61-614 Poznan, Poland; (A.K.); (W.J.)
| | - Anna Kicinska
- Department of Bioenergetics, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 6, 61-614 Poznan, Poland; (A.K.); (W.J.)
| | - Witold Nowak
- Molecular Biology Techniques Laboratory, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 6, 61-614 Poznan, Poland;
| | - Wieslawa Jarmuszkiewicz
- Department of Bioenergetics, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznanskiego 6, 61-614 Poznan, Poland; (A.K.); (W.J.)
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Tsai CM, Chen CH, Cheng WH, Stelma FF, Li SC, Lin WC. Homeostasis of cellular amino acids in Acanthamoeba castellanii exposed to different media under amoeba-bacteria coculture conditions. BMC Microbiol 2023; 23:198. [PMID: 37495951 PMCID: PMC10373360 DOI: 10.1186/s12866-023-02942-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 07/11/2023] [Indexed: 07/28/2023] Open
Abstract
BACKGROUND Acanthamoeba castellanii is a free-living protist that feeds on diverse bacteria. A. castellanii has frequently been utilized in studies on microbial interactions. Grazing bacteria also exhibit diverse effects on the physiological characteristics of amoebae, such as their growth, encystation, and cytotoxicity. Since the composition of amoebae amino acids is closely related to cellular activities, it can indicate the overall responses of A. castellanii to various stimuli. METHOD A. castellanii was exposed to different culture conditions in low-nutrient medium with heat-killed DH5α to clarify their effects. A targeted metabolomic technique was utilized to evaluate the concentration of cellular amino acids. The amino acid composition and pathways were analyzed by two web-based tools: MetaboAnalyst and Pathview. Then, long-term exposure to A. castellanii was investigated through in silico and in vitro methods to elucidate the homeostasis of amino acids and the growth of A. castellanii. RESULTS Under short-term exposure, all kinds of amino acids were enriched in all exposed groups. In contrast to the presence of heat-killed bacteria, the medium exhibited obvious effects on the amino acid composition of A. castellanii. After long-term exposure, the amino acid composition was more similar to that of the control group. A. castellanii may achieve amino acid homeostasis through pathways related to alanine, aspartate, citrulline, and serine. DISCUSSION Under short-term exposure, compared to the presence of bacteria, the type of medium exerted a more powerful effect on the amino acid composition of the amoeba. Previous studies focused on the interaction of the amoeba and bacteria with effective secretion systems and effectors. This may have caused the effects of low-nutrient environments to be overlooked. CONCLUSION When A. castellanii was stimulated in the coculture system through various methods, such as the presence of bacteria and a low-nutrient environment, it accumulated intracellular amino acids within a short period. However, different stimulations correspond to different amino acid compositions. After long-term exposure, A. castellanii achieved an amino acid equilibrium by downregulating the biosynthesis of several amino acids.
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Affiliation(s)
- Chih-Ming Tsai
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Chun-Hsien Chen
- Department of Parasitology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Wei-Hung Cheng
- Department of Parasitology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Foekje F. Stelma
- Department of Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands
| | - Sung-Chou Li
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
- Department of Nursing, Meiho University, Pingtung, Taiwan
| | - Wei-Chen Lin
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Parasitology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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Kim MJ, Moon EK, Jo HJ, Quan FS, Kong HH. Identifying the function of genes involved in excreted vesicle formation in Acanthamoeba castellanii containing Legionella pneumophila. Parasit Vectors 2023; 16:215. [PMID: 37380986 DOI: 10.1186/s13071-023-05824-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 05/28/2023] [Indexed: 06/30/2023] Open
Abstract
BACKGROUND Legionella spp. can survive and replicate inside host cells such as protozoa and macrophages. After enough growth, Legionella is released from the host cells as free legionellae or Legionella-filled vesicles. The vesicles support Legionella to survive for a long time in the environment and transmit to a new host. In this study, we identified the differentially expressed genes of Acanthamoeba infected by Legionella (ACA1_114460, ACA1_091500, and ACA1_362260) and examined their roles in the formation of the excreted vesicles and escape of Legionella from the Acanthamoeba. METHODS After ingestion of Escherichia coli and Legionella pneumophila, expression levels of target genes in Acanthamoeba were measured by real-time polymerase chain reaction (PCR) analysis. The roles of target genes were investigated by transfection of small interfering RNA (siRNA). The formation of Legionella-containing excreted vesicles and the vesicular co-localization with the lysosomes were examined by Giemsa stain and LysoTracker stain. RESULTS ACA1_114460, ACA1_091500, and ACA1_362260 were upregulated after ingestion of Legionella in Acanthamoeba. ACA1_114460- and ACA1_091500-silenced Acanthamoeba failed to form the Legionella-containing excreted vesicles. Legionella was released as free legionellae from the Acanthamoeba. When the ACA1_362260 of Acanthamoeba was silenced, Legionella-containing excreted vesicles were fused with the lysosome. CONCLUSIONS These results indicated that ACA1_114460, ACA1_091500, and ACA1_362260 of Acanthamoeba played important roles in the formation of Legionella-containing excreted vesicles and inhibition of the lysosomal co-localization with the phagosome.
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Affiliation(s)
- Min-Jeong Kim
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - Eun-Kyung Moon
- Department of Medical Zoology, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - Hye-Jeong Jo
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - Fu-Shi Quan
- Department of Medical Zoology, Kyung Hee University School of Medicine, Seoul, Republic of Korea
- Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, School of Medicine, Graduate school, Kyung Hee University, Seoul, Republic of Korea
| | - Hyun-Hee Kong
- Department of Parasitology, Dong-A University College of Medicine, Busan, Republic of Korea.
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Abdullah Hamad A. In vitro Evaluation the Efficacy of Some Nnew Plant Extracts and Biocides on the Viability of Acanthamoeba castellanii. Protist 2023; 174:125966. [PMID: 37229821 DOI: 10.1016/j.protis.2023.125966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 04/25/2023] [Accepted: 05/02/2023] [Indexed: 05/27/2023]
Abstract
The purpose of this study was to assess the efficacy of certain plant extracts and to compare them with current biocides on the viability of Acanthamoeba castellanii cysts and trophozoites in vitro. Amoebicidal and cysticidal assays were performed against both trophozoites and cysts of Acanthamoeba castellanii (ATCC 50370). Ten plant extracts were evaluated alongside the current agents included polyhexamethylene biguanide (PHMB), octenidine and chlorhexidine digluconate. A. castellanii (ATCC 50370) was treated to serial two-fold dilutions of the test compounds and extracts in microtitre plate wells to investigate the effect on trophozoites and cysts of A. castellanii (ATCC 50370). Furthermore, the toxicity of each of the test compounds and extracts were assessed towards a mammalian cell line. Minimum trophozoite inhibitory concentration (MTIC), minimum trophozoite amoebicidal concentration (MTAC), and minimum cysticidal concentration (MCC) were used to establish A. castellanii (ATCC 50370) in vitro sensitivity. The findings of this research revealed that the biguanides PHMB, chlorhexidine, and octenidine all had excellent effectiveness against trophozoites and cysts of A. castellanii (ATCC 50370). The plant extracts testing results showed that, great activity against trophozoites and cysts ofA. castellanii (ATCC 50370) at lower concentrations. This is the first study to demonstrate that the Proskia plant extract had the lowest MCC value, which was 3.9 µg/mL. The time kill experiment confirmed this finding, as this extract reduced cysts of A. castellanii (ATCC 50370) by more than 3-log at 6 hour and by 4-log after 24 hour. The anti-amoebic efficacy of new plant extracts on the viability of A. castellanii (ATCC 50370) cysts and trophozoites was comparable to existing biocide treatments and was not toxic when tested on a mammalian cell line. This could be a promising novel Acanthamoeba treatment by using the tested plant extracts as a monotherapy against trophozoites and cysts.
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Affiliation(s)
- Anas Abdullah Hamad
- University of Fallujah, College of Veterinary Medicine, Branch of Microbiology, Iraq, AL Anbar, Fallujah, Iraq.
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Akbar N, Khan NA, Giddey AD, Soares NC, Alharbi AM, Alfahemi H, Siddiqui R. Selected Gut Bacteria from Water Monitor Lizard Exhibit Effects against Pathogenic Acanthamoeba castellanii Belonging to the T4 Genotype. Microorganisms 2023; 11:microorganisms11041072. [PMID: 37110494 PMCID: PMC10142573 DOI: 10.3390/microorganisms11041072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 04/10/2023] [Accepted: 04/17/2023] [Indexed: 04/29/2023] Open
Abstract
Water monitor lizards (WMLs) reside in unhygienic and challenging ecological surroundings and are routinely exposed to various pathogenic microorganisms. It is possible that their gut microbiota produces substances to counter microbial infections. Here we determine whether selected gut bacteria of water monitor lizards (WMLs) possess anti-amoebic properties using Acanthamoeba castellanii of the T4 genotype. Conditioned media (CM) were prepared from bacteria isolated from WML. The CM were tested using amoebicidal, adhesion, encystation, excystation, cell cytotoxicity and amoeba-mediated host cell cytotoxicity assays in vitro. Amoebicidal assays revealed that CM exhibited anti-amoebic effects. CM inhibited both excystation and encystation in A. castellanii. CM inhibited amoebae binding to and cytotoxicity of host cells. In contrast, CM alone showed limited toxic effects against human cells in vitro. Mass spectrometry revealed several antimicrobials, anticancer, neurotransmitters, anti-depressant and other metabolites with biological functions. Overall, these findings imply that bacteria from unusual places, such as WML gut, produce molecules with anti-acanthamoebic capabilities.
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Affiliation(s)
- Noor Akbar
- Department of Clinical Sciences, College of Medicine, University of Sharjah, University City, Sharjah 27272, United Arab Emirates
- Sharjah Institute for Medical Research, University of Sharjah, Sharjah 27272, United Arab Emirates
| | - Naveed Ahmed Khan
- Department of Clinical Sciences, College of Medicine, University of Sharjah, University City, Sharjah 27272, United Arab Emirates
- Department of Medical Biology, Faculty of Medicine, Istinye University, Istanbul 34010, Turkey
| | - Alexander D Giddey
- Sharjah Institute for Medical Research, University of Sharjah, Sharjah 27272, United Arab Emirates
| | - Nelson C Soares
- Sharjah Institute for Medical Research, University of Sharjah, Sharjah 27272, United Arab Emirates
- Department of Medicinal Chemistry, College of Pharmacy, University of Sharjah, Sharjah 27272, United Arab Emirates
| | - Ahmad M Alharbi
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Taif University, Taif 21944, Saudi Arabia
| | - Hasan Alfahemi
- Department of Medical Microbiology, Faculty of Medicine, Al-Baha University, P.O. Box. 1988, Al-Baha 65799, Saudi Arabia
| | - Ruqaiyyah Siddiqui
- Department of Medical Biology, Faculty of Medicine, Istinye University, Istanbul 34010, Turkey
- College of Arts and Sciences, American University of Sharjah, University City, Sharjah 26666, United Arab Emirates
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Bahrami S, Asadi Z, Zarei M, Hamidinejat H, Henriquez FL. Exposure to sublethal concentrations of chlorine enhances the cytotoxicity of Acanthamoeba castellanii. Parasitol Res 2023; 122:1371-1380. [PMID: 37037947 DOI: 10.1007/s00436-023-07837-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 03/30/2023] [Indexed: 04/12/2023]
Abstract
Free-living amoebae belonging to the genus Acanthamoeba are the causative agents of infections in humans and animals. Many studies are being conducted to find effective compounds against amoebae, but their sublethal concentration effects on surviving amoebae seem to have been overlooked. Chlorine is a common disinfection agent commonly added to public water facilities and supplies. In this study, the cytopathic and phagocytic properties of Acanthamoeba castellanii trophozoites following exposure to sublethal concentrations of chlorine were examined. Two hours of exposure to 5 ppm hypochlorite calcium was considered the sublethal concentration for A. castellanii trophozoites. To compare the pathogenic potential of treated and untreated Acanthamoeba trophozoites, cytotoxicity, adhesion assays in RAW 264.7 macrophages, osmo, and thermotolerance tests were carried out. Bacterial uptake was assessed in treated cells to evaluate their phagocytic characteristics. Oxidative stress biomarkers and antioxidant activities were compared in treated and untreated trophozoites. Finally, the mRNA expression of the mannose-binding protein (MBP), cysteine protease 3 (CP3), and serine endopeptidase (SEP) genes was determined in cells. In all the experiments, untreated trophozoites were considered the control. In comparison to untreated trophozoites, in chlorine-treated trophozoites, cytopathic effects were more extensive and resulted in the detachment of macrophage monolayers. Treated trophozoites could not grow at high temperatures (43 °C). Besides, they showed osmotolerance to 0.5 M D-mannitol but not to 1 M. Results demonstrated a higher bacterial uptake rate by chlorine-treated trophozoites than untreated cells. The treated and untreated cells had significantly different glutathione and glutathione/glutathione disulfide ratios. Antioxidant enzyme activities, total antioxidant capacity, and malondialdehyde levels were increased significantly in chlorine-treated cells. Quantifying mRNA expression in chlorine-treated trophozoites revealed that virulence genes were upregulated. Chlorine can form resistance and virulent amoebae if it is not used at a proper concentration and exposure time. Identification of stress responses, their mechanisms in Acanthamoeba, and their relation to amoeba virulence would give us a better perception of their pathophysiology.
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Affiliation(s)
- Somayeh Bahrami
- Department of Parasitology, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
| | - Zeinab Asadi
- Department of Parasitology, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
| | - Mehdi Zarei
- Department of Food Hygiene, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
| | - Hossein Hamidinejat
- Department of Parasitology, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
| | - Fiona L Henriquez
- Institute of Biomedical and Environmental Health Research, School of Health and Life Sciences, University of the West of Scotland (UWS), Paisley, PA1 2BE, Scotland, UK
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Siddiqui R, Makhlouf Z, Akbar N, Khamis M, Ibrahim T, Khan AS, Khan NA. Antiamoebic properties of Methyltrioctylammonium chloride based deep eutectic solvents. Cont Lens Anterior Eye 2023; 46:101758. [PMID: 36243521 DOI: 10.1016/j.clae.2022.101758] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 09/06/2022] [Accepted: 09/09/2022] [Indexed: 11/25/2022]
Abstract
PURPOSE This aim of this study was to assess anti-parasitic properties of deep eutectic solvents against eye pathogen, Acanthamoeba, often associated with the use of contact lens. METHODS Assays were performed to investigate the effects of various Methyltrioctylammonium chloride-based deep eutectic solvents on Acanthamoeba castellanii, comprising amoebicidal assays, encystment assays, excystment assays, cytotoxicity assays by measuring lactate dehydrogenase release from human cells, and cytopathogenicity assays to determine parasite-mediated host cell death. RESULTS In a 2 h incubation period, DES-B, DES-C, DES-D, and DES-E exhibited up to 85 % amoebicidal activity at micromolar doses, which was enhanced further following 24 h incubation. When tested in encystment assays, selected deep eutectic solvents abolished cyst formation and were able to block excystment of A. castellanii. All solvents exhibited minimal human cell cytotoxicity except DES-D. Finally, all tested deep eutectic solvents inhibited amoeba-mediated cytopathogenicity, except DES-B. CONCLUSIONS Deep eutectic solvents show potent antiamoebic effects. These findings are promising and could lead to the development of novel contact lens disinfectants, as well as opening several avenues to explore the molecular mechanisms, various doses and incubation periods, and use of different bases against Acanthamoeba castellanii.
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Affiliation(s)
- Ruqaiyyah Siddiqui
- College of Arts and Sciences, American University of Sharjah, University City, Sharjah 26666, United Arab Emirates; Istinye Faculty of Medicine, Istinye University, Istanbul, Turkey
| | - Zinb Makhlouf
- College of Arts and Sciences, American University of Sharjah, University City, Sharjah 26666, United Arab Emirates
| | - Noor Akbar
- College of Arts and Sciences, American University of Sharjah, University City, Sharjah 26666, United Arab Emirates
| | - Mustafa Khamis
- College of Arts and Sciences, American University of Sharjah, University City, Sharjah 26666, United Arab Emirates
| | - Taleb Ibrahim
- Department of Chemical Engineering, College of Engineering, American University of Sharjah, P.O. Box 26666, Sharjah, United Arab Emirates
| | - Amir Sada Khan
- Department of Chemical Engineering, College of Engineering, American University of Sharjah, P.O. Box 26666, Sharjah, United Arab Emirates; Department of Chemistry, University of Science & Technology, Banuu 28100, Khyber Pakhtunkhwa, C
| | - Naveed Ahmed Khan
- Department of Clinical Sciences, College of Medicine, University of Sharjah, University, City, Sharjah 27272, United Arab Emirates; Istinye Faculty of Medicine, Istinye University, Istanbul, Turkey..
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Akbar N, Kawish M, Jabri T, Khan NA, Shah MR, Siddiqui R. Cinnamic acid and lactobionic acid based nanoformulations as a potential antiamoebic therapeutics. Exp Parasitol 2023; 246:108474. [PMID: 36708943 DOI: 10.1016/j.exppara.2023.108474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 12/30/2022] [Accepted: 01/24/2023] [Indexed: 01/26/2023]
Abstract
Acanthamoeba castellanii causes granulomatous amoebic encephalitis, an uncommon but severe brain infection and sight-threatening Acanthamoeba keratitis. Most of the currently used anti-amoebic treatments are not always effective, due to persistence of the cyst stage, and recurrence can occur. Here in this study we synthesize cinnamic acid and lactobionic acid-based magnetic nanoparticles (MNPs) using co-precipitation technique. These nanoformulations were characterized by Fourier transform infrared spectroscopy and Atomic form microscopy. The drugs alone (Hesperidin, Curcumin and Amphotericin B), magnetic NPs alone, and drug-loaded nano-formulations were evaluated at a concentration of 100 μg/mL for antiamoebic activity against a clinical isolate of A. castellanii. Amoebicidal assays revealed that drugs and conjugation of drugs and NPs further enhanced amoebicidal effects of drug-loaded nanoformulations. Drugs and drug-loaded nanoformulations inhibited both encystation and excystation of amoebae. In addition, drugs and drug-loaded nanoformulations inhibited parasite binding capability to the host cells. Neither drugs nor drug-loaded nanoformulations showed cytotoxic effects against host cells and considerably reduced parasite-mediated host cell death. Overall, these findings imply that conjugation of medically approved drugs with MNPs produce potent anti-Acanthamoebic effects, which could eventually lead to the development of therapeutic medications.
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Affiliation(s)
- Noor Akbar
- College of Arts and Sciences, American University of Sharjah, University City, Sharjah, 26666, United Arab Emirates; Department of Clinical Sciences, College of Medicine, University of Sharjah, University City, Sharjah, 27272, United Arab Emirates; Research Institute of Medical and Health Sciences (RIMHS), University of Sharjah, University City, Sharjah, 27272, United Arab Emirates.
| | - Muhammad Kawish
- H.E.J. Research Institute of Chemistry, International Centre for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan
| | - Tooba Jabri
- H.E.J. Research Institute of Chemistry, International Centre for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan
| | - Naveed Ahmed Khan
- Department of Clinical Sciences, College of Medicine, University of Sharjah, University City, Sharjah, 27272, United Arab Emirates; Research Institute of Medical and Health Sciences (RIMHS), University of Sharjah, University City, Sharjah, 27272, United Arab Emirates; Department of Medical Biology, Faculty of Medicine, Istinye University, Istanbul, 34010, Turkey.
| | - Muhammad Raza Shah
- H.E.J. Research Institute of Chemistry, International Centre for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan
| | - Ruqaiyyah Siddiqui
- College of Arts and Sciences, American University of Sharjah, University City, Sharjah, 26666, United Arab Emirates; Department of Medical Biology, Faculty of Medicine, Istinye University, Istanbul, 34010, Turkey
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22
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Hernández-Ramírez VI, Estrada-Figueroa LA, Medina Y, Lizarazo-Taborda MR, Toledo-Leyva A, Osorio-Trujillo C, Morales-Mora D, Talamás-Rohana P. A monoclonal antibody against a Leishmania mexicana COX-like enzymatic activity also recognizes similar proteins in different protozoa of clinical importance. Parasitol Res 2023; 122:479-492. [PMID: 36562799 DOI: 10.1007/s00436-022-07746-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022]
Abstract
In Leishmania mexicana, the protease gp63 has been documented as the protein responsible for cyclooxygenase (COX) activity. The present work aimed to obtain a monoclonal antibody capable of recognizing this protein without blocking the COX-like enzymatic activity. The antibody produced by the selected hybridoma was named D12 mAb. The antigen recognized by the D12 mAb was characterized by the determination of COX activity associated with immune complexes in the presence of exogenous arachidonic acid (AA) using the commercial Activity Assay Abcam kit. LSM-SMS analysis validated the identity of the antigen associated with the D12 mAb as the L. mexicana protease gp63. Confocal microscopy assays with the D12 mAb detected, by cross-recognition, similar proteins in other protozoan parasites. COX-like molecules are located in vesicular structures, homogeneously distributed throughout the cytoplasm in amastigotes (intracellular infectious phase) and promastigotes of L. mexicana, and trophozoites of Entamoeba histolytica, Acanthamoeba castellanii, and Naegleria fowleri. However, in Giardia duodenalis trophozoites, the distribution of the COX-like molecule was also in perinuclear areas. In comparison, in Trypanosoma cruzi trypomastigotes, the distribution was mainly observed in the plasma membrane. Structural analyses of COX-2-like antigens revealed continuous and discontinuous epitopes for B cells, which could be relevant in the cross-reaction of D12 mAb with the analyzed parasites. These results indicate that the D12 mAb against the L. mexicana gp63 also recognizes a COX-like molecule in several protozoan parasites, suggesting that this D12 mAb could potentially be used in combined therapies against infectious diseases.
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Affiliation(s)
- Verónica I Hernández-Ramírez
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y Estudios Avanzados, CINVESTAV-IPN, Ciudad de México, CP, 07360, México
| | - Luis A Estrada-Figueroa
- Instituto Mexicano de la Propiedad Industrial, Arenal Número 550, Primer piso, Pueblo Santa María, Ciudad de México, CP16020, México
| | - Yolanda Medina
- Laboratorio de Anticuerpos Monoclonales Unidad de Desarrollo Tecnológico e Investigación Molecular INDRE, Francisco de P. Miranda 177, Lomas de Plateros, Álvaro Obregón, Ciudad México, CP 01480, México
| | - Mélida R Lizarazo-Taborda
- Programa de Maestría en Microbiología Médica, Departamento de Microbiología y Patología, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, México
| | - Alfredo Toledo-Leyva
- Instituto Nacional de Cancerología., Av. San Fernando 22, Belisario Domínguez Secc 16, Tlalpan, Ciudad de México, CP 14080, México
| | - Carlos Osorio-Trujillo
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y Estudios Avanzados, CINVESTAV-IPN, Ciudad de México, CP, 07360, México
| | - Daniel Morales-Mora
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y Estudios Avanzados, CINVESTAV-IPN, Ciudad de México, CP, 07360, México
| | - Patricia Talamás-Rohana
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y Estudios Avanzados, CINVESTAV-IPN, Ciudad de México, CP, 07360, México.
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23
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Cha GY, Seo H, Oh J, Kim BJ, Kim BJ. Potential Use of Mycobacterium paragordonae for Antimycobacterial Drug Screening Systems. J Microbiol 2023; 61:121-9. [PMID: 36719620 DOI: 10.1007/s12275-022-00009-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 10/20/2022] [Accepted: 11/25/2022] [Indexed: 02/01/2023]
Abstract
Our recent genome-based study indicated that Mycobacterium paragordonae (Mpg) has evolved to become more adapted to an intracellular lifestyle within free-living environmental amoeba and its enhanced intracellular survival within Acanthamoeba castellanii was also proved. Here, we sought to investigate potential use of Mpg for antimycobacterial drug screening systems. Our data showed that Mpg is more susceptible to various antibiotics compared to the close species M. marinum (Mmar) and M. gordonae, further supporting its intracellular lifestyle in environments, which would explain its protection from environmental insults. In addition, we developed two bacterial whole-cell-based drug screening systems using a recombinant Mpg stain harboring a luciferase reporter vector (rMpg-LuxG13): one for direct application to rMpg-LuxG13 and the other for drug screening via the interaction of rMpg-LuxG13 with A. castellanii. Direct application to rMpg-LuxG13 showed lower inhibitory concentration 50 (IC50) values of rifampin, isoniazid, clarithromycin, and ciprofloxacin against Mpg compared to Mmar. Application of drug screening system via the interaction of rMpg-LuxG13 with A. castellanii also exhibited lower IC50 values for rifampin against Mpg compared to Mmar. In conclusion, our data indicate that Mpg is more susceptible to various antibiotics than other strains. In addition, our data also demonstrate the feasibility of two whole cell-based drug screening systems using rMpg-LuxG13 strain for the discovery of novel anti-mycobacterial drugs.
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24
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Goyal N, Barai A, Sen S, Kondabagil K. Amoebal Tubulin Cleavage Late during Infection Is a Characteristic Feature of Mimivirus but Not of Marseillevirus. Microbiol Spectr 2022; 10:e0275322. [PMID: 36453900 PMCID: PMC9769910 DOI: 10.1128/spectrum.02753-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 11/04/2022] [Indexed: 12/03/2022] Open
Abstract
Mimivirus and Marseillevirus infections of Acanthamoeba castellanii, like most other viral infections, induce cytopathic effects (CPE). The details of how they bring about CPE and to what extent and how they modify the host cytoskeletal network are unclear. In this study, we compared the rearrangement of the host cytoskeletal network induced by Mimivirus and Marseillevirus upon infection. We show that while both Mimivirus and Marseillevirus infections of A. castellanii cells cause retraction of acanthopodia and depolymerization of the host actin filament network, the Mimivirus infection also results in characteristic cleavage of the host tubulin, a phenomenon not previously reported with any intracellular pathogens. Furthermore, we show that the amoebal tubulin cleavage during Mimivirus infection is a post-replicative event. Because time-lapse microscopy showed that Mimivirus infection leads to the bursting of cells, releasing the virus, we hypothesize that tubulin cleavage together with actin depolymerization during the later stages of Mimivirus assembly is essential for cell lysis due to apoptotic/necrotic cell death. We also characterize the Mimivirus-encoded gp560, a Zn metalloprotease, however, the purified gp560 protein was unable to cleave the commercially available porcine brain tubulin. While protein synthesis is essential for causing the morphological changes in the case of Mimivirus, the proteins which are packaged in the viral capsid along with the genome are sufficient to induce CPE in the case of Marseillevirus. IMPORTANCE In general, intracellular pathogens target the cytoskeletal network to enable their life cycle inside the host. Pathogen-induced changes in the host cell morphology usually accompany global changes in the cytoskeleton resulting in cytopathic effects. While viruses have been shown to use the host actin cytoskeleton for entry and transport during early infection, the role of microtubules in the viral life cycle is only beginning to emerge. Here, we show that the giant viruses Mimivirus and Marseillevirus both induce depolymerization of the actin filament, Mimivirus also causes a characteristic cleavage of tubulin not previously reported for any intracellular pathogen. Because tubulin cleavage occurs late during infection, we hypothesize that tubulin cleavage aids in cell death and lysis rather than establishing infection. The different strategies used by viruses with similar host niches may help them survive in competition.
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Affiliation(s)
- Nisha Goyal
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Amlan Barai
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Shamik Sen
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Kiran Kondabagil
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
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25
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Lê HG, Choi JS, Hwang BS, Jeong YT, Kang JM, Võ TC, Cho PY, Lee YK, Yoo WG, Hong Y, Oh YT, Na BK. Phragmites australis (Cav.) Trin. ex Steud. Extract Induces Apoptosis-like Programmed Cell Death in Acanthamoeba castellanii Trophozoites. Plants (Basel) 2022; 11:3459. [PMID: 36559571 PMCID: PMC9783201 DOI: 10.3390/plants11243459] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 11/23/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
Acanthamoeba keratitis (AK) is an infectious ocular disease which is difficult to diagnose correctly and cure. Development of an effective and safe therapeutic drug for AK is needed. Our preliminary screening of more than 200 extracts from wild plants collected in Korea suggested the potential amoebicidal activity of Phragmites australis (Cav.) Trin. ex Steud. extract (PAE) against Acanthamoeba species. Here, we aimed to analyze the amoebicidal activity of PAE on Acanthamoeba and its underlying amoebicidal mechanism. PAE induced amoebicidal activity against both A. castellanii and A. polyphaga trophozoites, while it showed low cytotoxicity in human corneal epithelial cells (HCE-2) and human retinal pigment epithelial cells (ARPE-19). Transmission electron microscopy analysis showed subcellular morphological changes, such as increased granules, abnormal mitochondria, and atypical cyst wall formation, in the PAE-treated A. castellanii. Fluorometric apoptosis assay and TUNEL assay revealed apoptosis-like programmed cell death (PCD) in the PAE-treated A. castellanii. The PAE treatment increased reactive oxygen species production and reduced mitochondrial membrane potential in the amoeba. The enhanced expression of autophagy-associated genes was also detected. These results suggested that PAE exerted a promising amoebicidal effect on A. castellanii trophozoites via the PCD pathway. PAE could be a potential candidate for developing a therapeutic drug for AK.
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Affiliation(s)
- Hương-Giang Lê
- Department of Parasitology and Tropical Medicine, Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju 52727, Republic of Korea
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Republic of Korea
| | - Ji-Su Choi
- Nakdonggang National Institute of Biological Resources, Sangju 37242, Republic of Korea
| | - Buyng-Su Hwang
- Nakdonggang National Institute of Biological Resources, Sangju 37242, Republic of Korea
| | - Yong-Tae Jeong
- Nakdonggang National Institute of Biological Resources, Sangju 37242, Republic of Korea
| | - Jung-Mi Kang
- Department of Parasitology and Tropical Medicine, Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju 52727, Republic of Korea
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Republic of Korea
| | - Tuấn-Cường Võ
- Department of Parasitology and Tropical Medicine, Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju 52727, Republic of Korea
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Republic of Korea
| | - Pyo-Yun Cho
- Nakdonggang National Institute of Biological Resources, Sangju 37242, Republic of Korea
| | - Young-Kyung Lee
- Nakdonggang National Institute of Biological Resources, Sangju 37242, Republic of Korea
| | - Won-Gi Yoo
- Department of Parasitology and Tropical Medicine, Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju 52727, Republic of Korea
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Republic of Korea
| | - Yeonchul Hong
- Department of Parasitology and Tropical Medicine, School of Medicine, Kyungpook National University, Daegu 41944, Republic of Korea
| | - Young-Taek Oh
- Nakdonggang National Institute of Biological Resources, Sangju 37242, Republic of Korea
| | - Byoung-Kuk Na
- Department of Parasitology and Tropical Medicine, Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju 52727, Republic of Korea
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Republic of Korea
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26
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Makhlouf Z, Akbar N, Khan NA, Shah MR, Alharbi AM, Alfahemi H, Siddiqui R. Antiamoebic Properties of Ceftriaxone and Zinc-Oxide-Cyclodextrin-Conjugated Ceftriaxone. Antibiotics (Basel) 2022; 11. [PMID: 36551378 DOI: 10.3390/antibiotics11121721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/20/2022] [Accepted: 11/20/2022] [Indexed: 12/05/2022] Open
Abstract
Acanthamoeba castellanii is a ubiquitous free-living amoeba capable of instigating keratitis and granulomatous amoebic encephalitis in humans. Treatment remains limited and inconsistent. Accordingly, there is a pressing need for novel compounds. Nanotechnology has been gaining attention for enhancing drug delivery and reducing toxicity. Previous work has shown that various antibiotic classes displayed antiamoebic activity. Herein, we employed two antibiotics: ampicillin and ceftriaxone, conjugated with the nanocarrier zinc oxide and β-cyclodextrin, and tested them against A. castellanii via amoebicidal, amoebistatic, encystment, excystment, cytopathogenicity, and cytotoxicity assays at a concentration of 100 μg/mL. Notably, zinc oxide β-cyclodextrin ceftriaxone significantly inhibited A. castellanii growth and cytopathogenicity. Additionally, both zinc oxide β-cyclodextrin ceftriaxone and ceftriaxone markedly inhibited A. castellanii encystment. Furthermore, all the tested compounds displayed negligible cytotoxicity. However, minimal anti-excystment or amoebicidal effects were observed for the compounds. Accordingly, this novel nanoconjugation should be employed in further studies in hope of discovering novel anti-Acanthamoeba compounds.
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27
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Martín-Escolano R, Pérez-Cordón G, Arán VJ, Marín C, Sánchez-Moreno M, Rosales MJ. 5-Nitroindazole derivatives as potential therapeutic alternatives against Acanthamoeba castellanii. Acta Trop 2022; 232:106538. [PMID: 35618027 DOI: 10.1016/j.actatropica.2022.106538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 05/20/2022] [Accepted: 05/22/2022] [Indexed: 11/29/2022]
Abstract
Amoebas of the genus Acanthamoeba are distributed worldwide, including species with a high pathogenic capacity for humans. In a similar way to what occurs with other parasitic protozoa, the available treatments show variable effectiveness in addition to high toxicity, which demands the development of new treatments. Positive results of 5-nitroindazole derivatives against several protozoa parasites suggest that these compounds may be a promising tool for the development of efficient antiparasitic drugs. In the present work we have evaluated the in vitro activity of ten 5-nitroindazole derivatives against Acanthamoeba castellanii trophozoites and cysts. To that end, AlamarBlue Assay Reagent® was used to determine the activity against trophozoites compared to the reference drug chlorhexidine digluconate. Cytotoxicity of the compounds was evaluated using Vero cells. The activity on cysts was evaluated by light microscopy and using a Neubauer chamber to quantifying cysts and presence of trophozoites, as an indication of cyst. Our results showed the effectiveness of the 5-nitroindazole derivatives tested against both trophozoites and cysts of A. castellani highlighting 5-nitroindazole derivative 8 which showed a 80% activity on cysts, which is higher than that of the reference drug. Moreover, 5-nitroindazole derivatives 8, 9 and 10 were more effective on trophozoites than the reference drug showing IC50 values lower than 5 µM. Taking together these results, these 5-nitroindazole derivatives specially compound 8, might be a promising alternative for the development of more efficient treatments against A. castellani infection.
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Affiliation(s)
- Rubén Martín-Escolano
- Laboratory of Molecular & Evolutionary Parasitology, RAPID group, School of Biosciences, University of Kent, Canterbury, CT27NJ, UK.
| | - Gregorio Pérez-Cordón
- Department of Parasitology, University of Granada, Severo Ochoa s/n, E-18071, Granada, Spain
| | - Vicente J Arán
- Instituto de Química Médica (IQM), Consejo Superior de Investigaciones Científicas (CSIC), Calle Juan de la Cierva 3, 28006 Madrid, Spain
| | - Clotilde Marín
- Department of Parasitology, University of Granada, Severo Ochoa s/n, E-18071, Granada, Spain
| | - Manuel Sánchez-Moreno
- Department of Parasitology, University of Granada, Severo Ochoa s/n, E-18071, Granada, Spain
| | - María José Rosales
- Department of Parasitology, University of Granada, Severo Ochoa s/n, E-18071, Granada, Spain.
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Akbar N, Siddiqui R, Khamis M, Ibrahim T, Khan NA. A novel montmorillonite clay-cetylpyridinium chloride complex as a potential antiamoebic composite material in contact lenses disinfection. Exp Parasitol 2022;:108330. [PMID: 35868573 DOI: 10.1016/j.exppara.2022.108330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 06/18/2022] [Accepted: 07/11/2022] [Indexed: 11/23/2022]
Abstract
BACKGROUND Acanthamoeba keratitis is a painful, sight-threatening infection. It is commonly associated with the use of contact lens. Several lines of evidence suggest inadequate contact lens solutions especially against the cyst forms of pathogenic Acanthamoeba, indicating the need to develop effective disinfectants. OBJECTIVE In this work, the application and assessment of montmorillonite clay (Mt-clay), cetylpyridinium chloride (CPC) and cetylpyridinium chloride-montmorillonite clay complex (CPC-Mt) against keratitis-causing A. castellanii belonging to the T4 genotype was studied. METHODS Adhesion to human cells and amoeba-mediated cytopathogenicity assays were conducted to determine the impact of Mt-clay, CPC and CPC-Mt complex on amoeba-mediated binding and host cell death. Furthermore, assays were also performed to determine inhibitory effects of Mt-clay, CPC and CPC-Mt complex on encystment and excystment. In addition, the cytotoxicity of Mt-clay, CPC and CPC-Mt complex against human cells was examined. RESULTS The results revealed that CPC and CPC-Mt complex presented significant antiamoebic effects against A. castellanii at microgram dose. Also, the CPC and CPC-Mt complex inhibited amoebae binding to host cells. Furthermore, CPC and CPC-Mt complex, were found to inhibit the encystment and excystment processes. Finally, CPC and CPC-Mt complex showed minimal host cell cytotoxicity. These results show that CPC and CPC-Mt complex exhibit potent anti-acanthamoebic properties. CONCLUSION Given the ease of usage, safety, cost-effectiveness and long-term stability, CPC and CPC-Mt complex can prove to be an excellent choice in the rational development of contact-lens disinfectants to eradicate pathogenic Acanthamoeba effectively.
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Ahmed U, Ho KY, Simon SE, Saad SM, Ong SK, Anwar A, Tan KO, Sridewi N, Khan KM, Khan NA, Anwar A. Potential anti-acanthamoebic effects through inhibition of CYP51 by novel quinazolinones. Acta Trop 2022; 231:106440. [PMID: 35378058 DOI: 10.1016/j.actatropica.2022.106440] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 03/27/2022] [Accepted: 03/30/2022] [Indexed: 12/01/2022]
Abstract
Acanthamoeba spp. are free living amoebae which can give rise to Acanthamoeba keratitis and granulomatous amoebic encephalitis. The surface of Acanthamoeba contains ergosterol which is an important target for drug development against eukaryotic microorganisms. A library of ten functionally diverse quinazolinone derivatives (Q1-Q10) were synthesised to assess their activity against Acanthamoeba castellanii T4. The in-vitro effectiveness of these quinazolinones were investigated against Acanthamoeba castellanii by amoebicidal, excystation, host cell cytopathogenicity, and NADPH-cytochrome c reductase assays. Furthermore, wound healing capability was assessed at different time durations. Maximum inhibition at 50 μg/mL was recorded for compounds Q5, Q6 and Q8, while the compound Q3 did not exhibit amoebicidal effects at tested concentrations. Moreover, LDH assay was conducted to assess the cytotoxicity of quinazolinones against HaCaT cell line. The results of wound healing assay revealed that all compounds are not cytotoxic and are likely to promote wound healing at 10 μg/mL. The excystation assays revealed that these compounds significantly inhibit the morphological transformation of A. castellanii. Compound Q3, Q7 and Q8 elevated the level of NADPH-cytochrome c reductase up to five folds. Sterol 14alpha-demethylase (CYP51) a reference enzyme in ergosterol pathway was used as a potential target for anti-amoebic drugs. In this study using i-Tasser, the protein structure of Acanthamoeba castellanii (AcCYP51) was developed in comparison with Naegleria fowleri protein (NfCYP51) structure. The sequence alignment of both proteins has shown 42.72% identity. Compounds Q1-Q10 were then molecularly docked with the predicted AcCYP51. Out of ten quinazolinones, three compounds (Q3, Q7 and Q8) showed good binding activity within 3 Å of TYR 114. The in-silico study confirmed that these compounds are the inhibitor of CYP51 target site. This report presents several potential lead compounds belonging to quinazolinone derivatives for drug discovery against Acanthamoeba infections.
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Affiliation(s)
- Usman Ahmed
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya, Selangor, Malaysia
| | - Keat-Yie Ho
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya, Selangor, Malaysia
| | - Samson Eugin Simon
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya, Selangor, Malaysia
| | | | - Seng-Kai Ong
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya, Selangor, Malaysia
| | - Areeba Anwar
- Faculty of Defence Science and Technology, National Defence University of Malaysia, Kuala Lumpur, Malaysia
| | - Kuan Onn Tan
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya, Selangor, Malaysia
| | - Nanthini Sridewi
- Faculty of Defence Science and Technology, National Defence University of Malaysia, Kuala Lumpur, Malaysia
| | - Khalid Mohammed Khan
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan; Department of Clinical Pharmacy, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Naveed Ahmed Khan
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, University City, United Arab Emirates
| | - Ayaz Anwar
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya, Selangor, Malaysia.
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Siddiqui R, Makhlouf Z, Akbar N, Khamis M, Ibrahim T, Khan AS, Khan NA. Antiamoebic properties of salicylic acid-based deep eutectic solvents for the development of contact lens disinfecting solutions against Acanthamoeba. Mol Biochem Parasitol 2022; 250:111493. [PMID: 35753525 DOI: 10.1016/j.molbiopara.2022.111493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 05/30/2022] [Accepted: 06/20/2022] [Indexed: 10/17/2022]
Abstract
Acanthamoeba castellanii is a protist pathogen that can cause sight-threatening keratitis and a fatal infection of the central nervous system, known as granulomatous amoebic encephalitis. In this study, effects of five malonic acid and salicylic acid-based deep eutectic solvents (DES) on A. castellanii were investigated. These are salicylic acid-trioctylphosphine (DES 1), salicylic acid- trihexylamine (DES 2), salicylic acid-trioctylamine (DES 3), malonic acid-trioctylphosphine (DES 4) and malonic acid-trihexylamine (DES 5). The experiments were done by performing amoebicidal, encystment, excystment, cytopathogenicity, and cytotoxicity assays. At micromolar dosage, the solvents DES 2 and DES 3 displayed significant amoebicidal effects (P<0.05), inhibited encystment and excystment, undermined the cell-mediated cytopathogenicity of A. castellanii, and also displayed minimal cytotoxicity to human cells. Conversely, the chemical components of these solvents: salicylic acid, trihexylamine, and trioctylamine showed minimal effects when tested individually. These results are very promising and to the best of our knowledge, are reported for the first time on the effects of deep eutectic solvents on amoebae. These results can be applied in the development of new formulations of novel contact lens disinfectants against Acanthamoeba castellanii.
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Affiliation(s)
- Ruqaiyyah Siddiqui
- College of Arts and Sciences, American University of Sharjah, University City, Sharjah 26666, United Arab Emirates
| | - Zinb Makhlouf
- College of Arts and Sciences, American University of Sharjah, University City, Sharjah 26666, United Arab Emirates
| | - Noor Akbar
- College of Arts and Sciences, American University of Sharjah, University City, Sharjah 26666, United Arab Emirates
| | - Mustafa Khamis
- College of Arts and Sciences, American University of Sharjah, University City, Sharjah 26666, United Arab Emirates
| | - Taleb Ibrahim
- Department of Chemical Engineering, College of Engineering, American University of Sharjah, P.O. Box 26666, Sharjah, United Arab Emirates
| | - Amir Sada Khan
- Department of Chemical Engineering, College of Engineering, American University of Sharjah, P.O. Box 26666, Sharjah, United Arab Emirates
| | - Naveed Ahmed Khan
- Department of Clinical Sciences, College of Medicine, University of Sharjah, University, City, Sharjah, 27272, United Arab Emirates.
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Milanes JE, Suryadi J, Monaghan NP, Harding EM, Morris CS, Rozema SD, Khalifa MM, Golden JE, Phan IQ, Zigweid R, Abendroth J, Rice CA, McCord HT, Wilson S, Fenwick MK, Morris JC. Characterization of Glucokinases from Pathogenic Free-Living Amoebae. Antimicrob Agents Chemother 2022; 66:e0237321. [PMID: 35604214 PMCID: PMC9211422 DOI: 10.1128/aac.02373-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 04/27/2022] [Indexed: 11/20/2022] Open
Abstract
Infection with pathogenic free-living amoebae, including Naegleria fowleri, Acanthamoeba spp., and Balamuthia mandrillaris, can lead to life-threatening illnesses, primarily because of catastrophic central nervous system involvement. Efficacious treatment options for these infections are lacking, and the mortality rate due to infection is high. Previously, we evaluated the N. fowleri glucokinase (NfGlck) as a potential target for therapeutic intervention, as glucose metabolism is critical for in vitro viability. Here, we extended these studies to the glucokinases from two other pathogenic free-living amoebae, including Acanthamoeba castellanii (AcGlck) and B. mandrillaris (BmGlck). While these enzymes are similar (49.3% identical at the amino acid level), they have distinct kinetic properties that distinguish them from each other. For ATP, AcGlck and BmGlck have apparent Km values of 472.5 and 41.0 μM, while Homo sapiens Glck (HsGlck) has a value of 310 μM. Both parasite enzymes also have a higher apparent affinity for glucose than the human counterpart, with apparent Km values of 45.9 μM (AcGlck) and 124 μM (BmGlck) compared to ~8 mM for HsGlck. Additionally, AcGlck and BmGlck differ from each other and other Glcks in their sensitivity to small molecule inhibitors, suggesting that inhibitors with pan-amoebic activity could be challenging to generate.
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Affiliation(s)
- Jillian E. Milanes
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, USA
| | - Jimmy Suryadi
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, USA
| | - Neil P. Monaghan
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, USA
| | - Elijah M. Harding
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, USA
| | - Corbin S. Morris
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, USA
| | - Soren D. Rozema
- School of Pharmacy, Pharmaceutical Sciences Division, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Muhammad M. Khalifa
- School of Pharmacy, Pharmaceutical Sciences Division, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Jennifer E. Golden
- School of Pharmacy, Pharmaceutical Sciences Division, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Isabelle Q. Phan
- Seattle Structural Genomics Center for Infectious Disease, Center for Global Infection Disease Research, Seattle Children’s Research Institute, Seattle, Washington, USA
| | - Rachael Zigweid
- Seattle Structural Genomics Center for Infectious Disease, Center for Global Infection Disease Research, Seattle Children’s Research Institute, Seattle, Washington, USA
| | - Jan Abendroth
- Seattle Structural Genomics Center for Infectious Disease, Center for Global Infection Disease Research, Seattle Children’s Research Institute, Seattle, Washington, USA
- UCB BioSciences, Bainbridge Island, Washington, USA
| | - Christopher A. Rice
- Pharmaceutical and Biomedical Sciences, Center for Drug Discovery, College of Pharmacy, University of Georgia, Athens, Georgia, USA
| | - Hayden T. McCord
- Pharmaceutical and Biomedical Sciences, Center for Drug Discovery, College of Pharmacy, University of Georgia, Athens, Georgia, USA
| | - Stevin Wilson
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, USA
- Genomics and Bioinformatics Facility, Clemson University, Clemson, South Carolina, USA
| | - Michael K. Fenwick
- Seattle Structural Genomics Center for Infectious Disease, Center for Global Infection Disease Research, Seattle Children’s Research Institute, Seattle, Washington, USA
| | - James C. Morris
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, USA
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Saeed BQ, Rawas-Qalaji M, Akbar N, Siddiqui R, Roberta C, Manzoor S, Muhammad JS, Adrees AO, Al-Shahrabi R, Khan NA. Evaluation of Nanoparticles with 5-Fluorouracil and Chloroquine on Acanthamoeba castellanii activity. Mol Biochem Parasitol 2022; 250:111492. [PMID: 35714753 DOI: 10.1016/j.molbiopara.2022.111492] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 05/30/2022] [Accepted: 06/08/2022] [Indexed: 01/04/2023]
Abstract
Acanthamoeba is opportunistic pathogens that cause vision-threatening Acanthamoeba keratitis (AK). Previous studies proposed the use of chloroquine (CQ) and 5-fluorouracil (5FU) as anti-Acanthamoeba agents. The objective of this study was to determine the benefit of using 5FU and CQ nanoparticles (NP) formulations against A. castellanii that belonging to the T4 genotype and evaluate their anti-Acanthamoebic characteristic. Triplicate batches of 5FU nanoparticles (5FU-NP) were synthesized by using a modified nanoprecipitation method, while CQ anoparticles (CQ-NP) synthesized using a modified double emulsion method. The synthesized nanoparticles were subjected to biological assays to investigate their amoebicidal, amoebistatic, anti-encystation, and anti-excystation effects against A. castellanii, as well as cell cytotoxicity. Cytotoxicity assays were performed using human keratinocyte cells (HaCat) to determine the effect of CQ and 5FU nanoformulations on host cells. 5FU-NP with a concentration of 60µM showed significant inhibition to amoeba binding into human cell lines and remarkable prevention mainly during the encystation stage. Moreover, 5FU-NP resulted in less cytotoxicity and pathogenicity when compared with the free 5FU. On the other hand, CQ and CQ-NP, at the same concentration, showed poor inhibition to amoeba binding into human cells and insignificant prevention to encystation stage. Moderate human cells damage was resulted following their treatment with CQ and CQ-NP. In conclusion, 5FU may have the potential as an antiamoebic agent against Acanthamoeba spp. preferably as a nanoformulation to enhance its activity and reduce its cytoxicity.
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Affiliation(s)
- Balsam Qubais Saeed
- Department of Clinical Sciences, College of Medicine, University of Sharjah, UAE; Research Institute of Medical and Health Sciences, University of Sharjah, Sharjah 27272, United Arab Emirates.
| | - Mutasem Rawas-Qalaji
- Research Institute of Medical and Health Sciences, University of Sharjah, Sharjah 27272, United Arab Emirates; College of Pharmacy, University of Sharjah, Sharjah, United Arab Emirates; Dr. Kiran C. Patel College of Allopathic Medicine, Nova Southeastern University, Fort Lauderdale, FL, USA
| | - Noor Akbar
- College of Arts and Sciences, American University of Sharjah, UAE
| | | | - Cagliani Roberta
- Research Institute of Medical and Health Sciences, University of Sharjah, Sharjah 27272, United Arab Emirates
| | - Shaista Manzoor
- Research Institute of Medical and Health Sciences, University of Sharjah, Sharjah 27272, United Arab Emirates; Department of Basic Medical Sciences, College of Medicine, University of Sharjah, Sharjah, 27272, United Arab Emirates
| | - Jibran Sualeh Muhammad
- Research Institute of Medical and Health Sciences, University of Sharjah, Sharjah 27272, United Arab Emirates; Department of Basic Medical Sciences, College of Medicine, University of Sharjah, Sharjah, 27272, United Arab Emirates
| | - Ahmed Omar Adrees
- College of Medicine, University of Sharjah, Sharjah, 27272, United Arab Emirates
| | - Rula Al-Shahrabi
- Department of Clinical Sciences, College of Medicine, University of Sharjah, UAE
| | - Naveed Ahmed Khan
- Department of Clinical Sciences, College of Medicine, University of Sharjah, UAE; Research Institute of Medical and Health Sciences, University of Sharjah, Sharjah 27272, United Arab Emirates
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Abstract
This article describes a practical method for prospecting and isolating giant viruses based on direct inoculation of environmental samples into amoeba cultures of Acanthamoeba castellanii. The giant viruses that infect amoebas have already been isolated from various environmental samples in several countries worldwide, including in extreme environments. Here we describe the methodologic procedures regarding the prospecting of giant viruses in A. castellanii, including the preparation of environmental samples, the culture of amoebas, and the observation of cytopathic effects that can indicate the presence and potential isolation of giant viruses. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Sample collection Support Protocol: Propagation of Acanthamoeba castellanii Basic Protocol 2: Prospecting of giant viruses in environmental samples by cytopathic effect analysis.
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Affiliation(s)
- Talita Bastos Machado
- Instituto de Ciências Biológicas, Departamento de Microbiologia, Laboratório de Vírus, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Isabella Luiza Martins de Aquino
- Instituto de Ciências Biológicas, Departamento de Microbiologia, Laboratório de Vírus, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Jônatas Santos Abrahão
- Instituto de Ciências Biológicas, Departamento de Microbiologia, Laboratório de Vírus, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
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Köhsler M, Leitsch D, Loufouma Mbouaka A, Wekerle M, Walochnik J. Transcriptional changes of proteins of the thioredoxin and glutathione systems in Acanthamoeba spp. under oxidative stress - an RNA approach. Parasite 2022; 29:24. [PMID: 35532265 PMCID: PMC9083255 DOI: 10.1051/parasite/2022025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 04/19/2022] [Indexed: 12/03/2022] Open
Abstract
The thioredoxin (Trx) and the glutathione (GSH) systems represent important antioxidant systems in cells and in particular thioredoxin reductase (TrxR) has been shown to constitute a promising drug target in parasites. For the facultative protozoal pathogen Acanthamoeba, it was demonstrated that a bacterial TrxR as well as a TrxR, characteristic of higher eukaryotes, mammals and humans is expressed on the protein level. However, only bacterial TrxR is strongly induced by oxidative stress in Acanthamoeba castellanii. In this study, the impact of oxidative stress on key enzymes involved in the thioredoxin and the glutathione system of A. castellanii under different culture conditions and of clinical Acanthamoeba isolates was evaluated on the RNA level employing RT-qPCR. Additionally, the effect of auranofin, a thioredoxin reductase inhibitor, already established as a potential drug in other parasites, on target enzymes in A. castellanii was investigated. Oxidative stress induced by hydrogen peroxide led to significant stimulation of bacterial TrxR and thioredoxin, while diamide had a strong impact on all investigated enzymes. Different strains displayed distinct transcriptional responses, rather correlating to sensitivity against the respective stressor than to respective pathogenic potential. Culture conditions appear to have a major effect on transcriptional changes in A. castellanii. Treatment with auranofin led to transcriptional activation of the GSH system, indicating its role as a potential backup for the Trx system. Altogether, our data provide more profound insights into the complex redox system of Acanthamoeba, preparing the ground for further investigations on this topic.
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Affiliation(s)
- Martina Köhsler
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Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna 1090 Vienna Austria
| | - David Leitsch
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Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna 1090 Vienna Austria
| | - Alvie Loufouma Mbouaka
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Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna 1090 Vienna Austria
| | - Maximilian Wekerle
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Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna 1090 Vienna Austria
| | - Julia Walochnik
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Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna 1090 Vienna Austria
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Grechnikova M, Arbon D, Ženíšková K, Malych R, Mach J, Krejbichová L, Šimáčková A, Sutak R. Elucidation of iron homeostasis in Acanthamoeba castellanii. Int J Parasitol 2022; 52:497-508. [PMID: 35533729 DOI: 10.1016/j.ijpara.2022.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 03/21/2022] [Accepted: 03/27/2022] [Indexed: 11/25/2022]
Abstract
Acanthamoeba castellanii is a ubiquitously distributed amoeba that can be found in soil, dust, natural and tap water, air conditioners, hospitals, contact lenses and other environments. It is an amphizoic organism that can cause granulomatous amoebic encephalitis, an infrequent fatal disease of the central nervous system, and amoebic keratitis, a severe corneal infection that can lead to blindness. These diseases are extremely hard to treat; therefore, a more comprehensive understanding of this pathogen's metabolism is essential for revealing potential therapeutic targets. To propagate successfully in human tissues, the parasites must resist the iron depletion caused by nutritional immunity. The aim of our study is to elucidate the mechanisms underlying iron homeostasis in A. castellanii. Using a comparative whole-cell proteomic analysis of cells grown under different degrees of iron availability, we identified the primary proteins involved in Acanthamoeba iron acquisition. Our results suggest a two-step reductive mechanism of iron acquisition by a ferric reductase from the STEAP family and a divalent metal transporter from the NRAMP family. Both proteins are localized to the membranes of acidified digestive vacuoles where endocytosed medium and bacteria are trafficked. The expression levels of these proteins are significantly higher under iron-limited conditions, which allows Acanthamoeba to increase the efficiency of iron uptake despite the observed reduced pinocytosis rate. We propose that excessive iron gained while grown under iron-rich conditions is removed from the cytosol into the vacuoles by an iron transporter homologous to VIT/Ccc1 proteins. Additionally, we identified a novel protein that may participate in iron uptake regulation, the overexpression of which leads to increased iron acquisition.
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Affiliation(s)
- Maria Grechnikova
- Department of Parasitology, Charles University, Faculty of Science, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Dominik Arbon
- Department of Parasitology, Charles University, Faculty of Science, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Kateřina Ženíšková
- Department of Parasitology, Charles University, Faculty of Science, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Ronald Malych
- Department of Parasitology, Charles University, Faculty of Science, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Jan Mach
- Department of Parasitology, Charles University, Faculty of Science, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Lucie Krejbichová
- Department of Parasitology, Charles University, Faculty of Science, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Aneta Šimáčková
- Department of Parasitology, Charles University, Faculty of Science, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Robert Sutak
- Department of Parasitology, Charles University, Faculty of Science, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic.
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de Carvalho Clímaco M, de Oliveira YLM, Ramos ACS, Ramos-de-Souza J, Silva ARST, Jain S, Rott MB, Scher R, Correa CB, Barbosa AAT, Dolabella SS. Nisin Induces Cell-Cycle Arrest in Free-Living Amoebae Acanthamoeba castellanii. Acta Parasitol 2022; 67:511-517. [PMID: 34156633 DOI: 10.1007/s11686-021-00436-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Accepted: 06/07/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE Acanthamoeba spp. are free-living amoebas with worldwide distribution and play an important role as disease-causing agents in humans. Drug inability to completely eradicate these parasites along with their toxic effects suggest urgent need for new antimicrobials. Nisin is a natural antimicrobial peptide produced by Lactococcus lactis. Nisin is also the only bacteriocin approved for use in food preservation. In this work, we analyzed the effect of nisin on the growth of Acanthamoeba castellanii trophozoites. METHODS A total of 8 × 104 trophozoites were exposed to increasing concentrations of nisin to determine its activity. Changes in cell membrane and cellular cycle of trophozoites were investigated by flow cytometry, and nisin cytotoxicity in mammalian cells was evaluated in L929 cells by MTT method. RESULTS After 24 h exposure to increasing nisin concentrations, an IC50 of 4493.2 IU mL-1 was obtained for A. castellanii trophozoites. However, after 72 h a recovery in amoebic growth was observed, and it was no longer possible to determine IC50. Flow cytometry analysis showed that nisin has no effect on the membrane integrity. Treatment with nisin induced cell-cycle arrest during G1 and S phases in A. castellanii trophozoites, which recovered their growth after 72 h. CONCLUSION This is one of the first studies showing the effect of internationally approved nisin against A. castellanii trophozoites. Nisin caused cell-cycle arrest in trophozoites, momentarily interfering with the DNA replication process. The data highlight the amoebostatic activity of nisin, and suggest its use as an adjuvant for the treatment of infections caused by Acanthamoeba spp.
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Abstract
The ubiquitous unicellular eukaryote, Acanthamoeba, is known to play a role in the survival and dissemination of Campylobacter jejuni. C. jejuni is the leading cause of bacterial foodborne gastroenteritis world-wide and is a major public health problem. The ability of C. jejuni to interact and potentially invade epithelial cells is thought to be key for disease development in humans. We examined C. jejuni grown under standard laboratory conditions, 11168HCBA with that harvested from within Acanthamoeba castellanii (11168HAC/CBA) or Acanthamoeba polyphaga (11168HAP/CBA), and compared their ability to invade different cell lines. C. jejuni harvested from within amoebae had a ~3.7-fold increase in invasiveness into T84 human epithelial cells and a striking ~11-fold increase for re-entry into A. castellanii cells. We also investigated the invasiveness and survivability of six diverse representative C. jejuni strains within Acanthamoeba spp., our results confirm that invasion and survivability is likely host-cell-dependent. Our survival assay data led us to conclude that Acanthamoeba spp. are a transient host for C. jejuni and that survival within amoebae pre-adapts C. jejuni and enhances subsequent cell invasion. This study provides new insight into C. jejuni interactions with amoebae and its increased invasiveness potential in mammalian hosts.
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Affiliation(s)
- Fauzy Nasher
- London School of Hygiene and Tropical Medicine, London, UK
| | - Brendan W Wren
- London School of Hygiene and Tropical Medicine, London, UK
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Wang YJ, Chen CH, Chen JW, Lin WC. Commensals Serve as Natural Barriers to Mammalian Cells during Acanthamoeba castellanii Invasion. Microbiol Spectr 2021; 9:e0051221. [PMID: 34935418 PMCID: PMC8693914 DOI: 10.1128/spectrum.00512-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 11/02/2021] [Indexed: 12/23/2022] Open
Abstract
Acanthamoeba castellanii is a free-living, pathogenic ameba found in the soil and water. It invades the body through ulcerated skin, the nasal passages, and eyes and can cause blinding keratitis and granulomatous encephalitis. However, the mechanisms underlying the opportunistic pathogenesis of A. castellanii remain unclear. In this study, we observed that commensal bacteria significantly reduced the cytotoxicity of the ameba on mammalian cells. This effect occurred in the presence of both Gram-positive and Gram-negative commensals. Additionally, commensals mitigated the disruption of cell junctions. Ex vivo experiments on mouse eyeballs further showed that the commensals protected the corneal epithelial layer. Together, these findings indicate that A. castellanii is pathogenic to individuals with a dysbiosis of the microbiota at infection sites, further highlighting the role of commensals as a natural barrier during parasite invasion. IMPORTANCE Acanthamoeba castellanii, an opportunistic protozoan widely present in the environment, can cause Acanthamoeba keratitis and encephalitis in humans. However, only a few reports describe how the ameba acts as an opportunistic pathogen. Our study showed that the normal microbiota interfered with the cytotoxicity of Acanthamoeba, persevered during Acanthamoeba invasion, and reduced corneal epithelium peeling in the mouse eyeball model. This suggests that commensals may act as a natural barrier against Acanthamoeba invasion. In future, individuals who suffer from Acanthamoeba keratitis should be examined for microbiota absence or dysbiosis to reduce the incidence of Acanthamoeba infection in clinical settings.
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Affiliation(s)
- Yu-Jen Wang
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Clinical Laboratory, Chest Hospital, Ministry of Health and Welfare, Tainan, Taiwan
| | - Chun-Hsien Chen
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Jenn-Wei Chen
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Wei-Chen Lin
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Parasitology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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Quirk S, Lieberman RL. Improved resolution crystal structure of Acanthamoeba actophorin reveals structural plasticity not induced by microgravity. Acta Crystallogr F Struct Biol Commun 2021; 77:452-458. [PMID: 34866600 PMCID: PMC8647214 DOI: 10.1107/s2053230x21011419] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 10/28/2021] [Indexed: 11/10/2022] Open
Abstract
Actophorin, a protein that severs actin filaments isolated from the amoeba Acanthamoeba castellanii, was employed as a test case for crystallization under microgravity. Crystals of purified actophorin were grown under microgravity conditions aboard the International Space Station (ISS) utilizing an interactive crystallization setup between the ISS crew and ground-based experimenters. Crystals grew in conditions similar to those grown on earth. The structure was solved by molecular replacement at a resolution of 1.65 Å. Surprisingly, the structure reveals conformational changes in a remote β-turn region that were previously associated with actophorin phosphorylated at the terminal residue Ser1. Although crystallization under microgravity did not yield a higher resolution than crystals grown under typical laboratory conditions, the conformation of actophorin obtained from solving the structure suggests greater flexibility in the actophorin β-turn than previously appreciated and may be beneficial for the binding of actophorin to actin filaments.
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Affiliation(s)
- Stephen Quirk
- Kimberley-Clark, 1400 Holcomb Bridge Road, Roswell, GA 30076, USA
| | - Raquel L. Lieberman
- Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, GA 30332, USA
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Kim DY, Son DH, Matin A, Jung SY. Production of a monoclonal antibody against a galactose-binding protein of Acanthamoeba castellanii and its cytotoxicity. Parasitol Res 2021; 120:3845-3850. [PMID: 34561750 DOI: 10.1007/s00436-021-07321-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 09/15/2021] [Indexed: 11/29/2022]
Abstract
In this study, it was confirmed whether the galactose-binding protein (GBP) was present in Acanthamoeba castellanii, and its function on a target cell was confirmed by production of an antibody against the GBP. Since the genes for GBP have not yet been identified at all, the purification of GBP was done using galactose-beads from amoebial lysates, and monoclonal antibodies were produced using cell fusion. GBP was confirmed to have a size of about 35 kDa. After the third immunization with purified GBP in BALB/c mice, monoclonal antibody production was analyzed. The clone cultured before limiting dilution was named 2AB2 and showed the highest antibody titer in the culture supernatant of a 24-well plate. AF6 clone cultured after limiting dilution showed an antibody titer of 0.259 in a 75-T flask. Antibodies generated by collecting ascites by injecting monoclonal colonies into the abdominal cavity of mice were confirmed through gel analysis and were observed to belong to the isotype of the IgM having kappa chains. Since the cytotoxicity of A. castellanii was inhibited by about 26% by the monoclonal antibody against GBP, it was confirmed that the antibody against GBP had an inhibitory effect on cytotoxicity. This study was the first report on GBP isolated and purified from A. castellanii, and similarly to a mannose-binding protein (MBP), its involvement in contact-dependent cytotoxicity was demonstrated with monoclonal antibody production.
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Affiliation(s)
- Dong-Youn Kim
- Department of Biomedical Laboratory Science, Molecular Diagnostics Research Institute, Namseoul University, 91 Daehak-ro, Seonghwan-eup, Cheonan, 31020, Republic of Korea
| | - Dae-Hyun Son
- Department of Biomedical Laboratory Science, Molecular Diagnostics Research Institute, Namseoul University, 91 Daehak-ro, Seonghwan-eup, Cheonan, 31020, Republic of Korea
| | - Abdul Matin
- Department of Biological Science, University of Baltistan, Kargil Road, Main Campus, SkarduHussainabad, Gilgit-Baltistan, 16100, Pakistan
| | - Suk-Yul Jung
- Department of Biomedical Laboratory Science, Molecular Diagnostics Research Institute, Namseoul University, 91 Daehak-ro, Seonghwan-eup, Cheonan, 31020, Republic of Korea.
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Martín-Escolano R, Molero Romero S, Díaz JG, Marín C, Sánchez-Moreno M, Rosales MJ. In vitro anti- Acanthamoeba activity of flavonoid glycosides isolated from Delphinium gracile, D. staphisagria, Consolida oliveriana and Aconitum napellus. Parasitology 2021; 148:1392-1400. [PMID: 34162452 PMCID: PMC11010224 DOI: 10.1017/s0031182021001025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 06/13/2021] [Accepted: 06/14/2021] [Indexed: 11/07/2022]
Abstract
Acanthamoeba spp. are widely distributed in the environment and cause serious infections in humans. Treatment of Acanthamoeba infections is very challenging and not always effective which requires the development of more efficient drugs against Acanthamoeba spp. The purpose of the present study was to test medicinal plants that may be useful in the treatment of Acanthamoeba spp. Here we evaluated the trophozoital and cysticidal activity of 13 flavonoid glycosides isolated from Delphinium gracile, D. staphisagria, Consolida oliveriana and from Aconitum napellus subsp. Lusitanicum against the amoeba Acanthamoeba castellanii. AlamarBlue Assay Reagent® was used to determine the activity against trophozoites of A. castellanii, and cytotoxic using Vero cells. Cysticidal activity was assessed on treated cysts by light microscopy using a Neubauer chamber to quantify cysts and trophozoites. Flavonoids 1, 2, 3 and 4 showed higher trophozoital activity and selectivity indexes than the reference drug chlorhexidine digluconate. In addition, flavonoid 2 showed 100% cysticidal activity at a concentration of 50 μm, lower than those of the reference drug and flavonoid 3 (100 μm). These results suggest that flavonoids 2 and 3 might be used for the development of novel therapeutic approaches against Acanthamoeba infections after satisfactory in vivo evaluations.
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Affiliation(s)
- Rubén Martín-Escolano
- Laboratory of Molecular & Evolutionary Parasitology, RAPID group, School of Biosciences, University of Kent, Canterbury, CT2 7NJ, UK
| | - Sonia Molero Romero
- Departamento de Parasitología, Instituto de Investigacion Biosanitaria Ibs, University of Granada, Severo Ochoa s/n, E-18071, Granada, Spain
| | - Jesus G. Díaz
- Departamento de Química Orgánica, Instituto de Bio-Orgánica ‘Antonio González’, Universidad de La Laguna, Ctra. a la Esperanza 2, 38206-La Laguna, Tenerife, Spain
| | - Clotilde Marín
- Departamento de Parasitología, Instituto de Investigacion Biosanitaria Ibs, University of Granada, Severo Ochoa s/n, E-18071, Granada, Spain
| | - Manuel Sánchez-Moreno
- Departamento de Parasitología, Instituto de Investigacion Biosanitaria Ibs, University of Granada, Severo Ochoa s/n, E-18071, Granada, Spain
| | - Mª José Rosales
- Departamento de Parasitología, Instituto de Investigacion Biosanitaria Ibs, University of Granada, Severo Ochoa s/n, E-18071, Granada, Spain
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Sahmi-Bounsiar D, Baudoin JP, Hannat S, Decloquement P, Chabrieres E, Aherfi S, La Scola B. Generation of Infectious Mimivirus Virions Through Inoculation of Viral DNA Within Acanthamoeba castellanii Shows Involvement of Five Proteins, Essentially Uncharacterized. Front Microbiol 2021; 12:677847. [PMID: 34305841 PMCID: PMC8299487 DOI: 10.3389/fmicb.2021.677847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 06/08/2021] [Indexed: 11/13/2022] Open
Abstract
One of the most curious findings associated with the discovery of Acanthamoeba polyphaga mimivirus (APMV) was the presence of many proteins and RNAs within the virion. Although some hypotheses on their role in Acanthamoeba infection have been put forward, none have been validated. In this study, we directly transfected mimivirus DNA with or without additional proteinase K treatment to extracted DNA into Acanthamoeba castellanii. In this way, it was possible to generate infectious APMV virions, but only without extra proteinase K treatment of extracted DNA. The virus genomes before and after transfection were identical. We searched for the remaining DNA-associated proteins that were digested by proteinase K and could visualize at least five putative proteins. Matrix-assisted laser desorption/ionization time-of-flight and liquid chromatography–mass spectrometry comparison with protein databases allowed the identification of four hypothetical proteins—L442, L724, L829, and R387—and putative GMC-type oxidoreductase R135. We believe that L442 plays a major role in this protein–DNA interaction. In the future, expression in vectors and then diffraction of X-rays by protein crystals could help reveal the exact structure of this protein and its precise role.
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Affiliation(s)
- Dehia Sahmi-Bounsiar
- IHU Méditerranée Infection, Marseille, France.,Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), Assistance Publique- Hôpitaux de Marseille (AP-HM), MEPHI, Marseille, France
| | - Jean-Pierre Baudoin
- IHU Méditerranée Infection, Marseille, France.,Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), Assistance Publique- Hôpitaux de Marseille (AP-HM), MEPHI, Marseille, France
| | - Sihem Hannat
- IHU Méditerranée Infection, Marseille, France.,Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), Assistance Publique- Hôpitaux de Marseille (AP-HM), MEPHI, Marseille, France
| | - Philippe Decloquement
- IHU Méditerranée Infection, Marseille, France.,Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), Assistance Publique- Hôpitaux de Marseille (AP-HM), MEPHI, Marseille, France
| | - Eric Chabrieres
- IHU Méditerranée Infection, Marseille, France.,Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), Assistance Publique- Hôpitaux de Marseille (AP-HM), MEPHI, Marseille, France
| | - Sarah Aherfi
- IHU Méditerranée Infection, Marseille, France.,Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), Assistance Publique- Hôpitaux de Marseille (AP-HM), MEPHI, Marseille, France
| | - Bernard La Scola
- IHU Méditerranée Infection, Marseille, France.,Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), Assistance Publique- Hôpitaux de Marseille (AP-HM), MEPHI, Marseille, France
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43
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Erber L, Betat H, Mörl M. CCA-Addition Gone Wild: Unusual Occurrence and Phylogeny of Four Different tRNA Nucleotidyltransferases in Acanthamoeba castellanii. Mol Biol Evol 2021; 38:1006-1017. [PMID: 33095240 PMCID: PMC7947759 DOI: 10.1093/molbev/msaa270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
tRNAs are important players in the protein synthesis machinery, where they act as adapter molecules for translating the mRNA codons into the corresponding amino acid sequence. In a series of highly conserved maturation steps, the primary transcripts are converted into mature tRNAs. In the amoebozoan Acanthamoeba castellanii, a highly unusual evolution of some of these processing steps was identified that are based on unconventional RNA polymerase activities. In this context, we investigated the synthesis of the 3′-terminal CCA-end that is added posttranscriptionally by a specialized polymerase, the tRNA nucleotidyltransferase (CCA-adding enzyme). The majority of eukaryotic organisms carry only a single gene for a CCA-adding enzyme that acts on both the cytosolic and the mitochondrial tRNA pool. In a bioinformatic analysis of the genome of this organism, we identified a surprising multitude of genes for enzymes that contain the active site signature of eukaryotic/eubacterial tRNA nucleotidyltransferases. In vitro activity analyses of these enzymes revealed that two proteins represent bona fide CCA-adding enzymes, one of them carrying an N-terminal sequence corresponding to a putative mitochondrial target signal. The other enzymes have restricted activities and represent CC- and A-adding enzymes, respectively. The A-adding enzyme is of particular interest, as its sequence is closely related to corresponding enzymes from Proteobacteria, indicating a horizontal gene transfer. Interestingly, this unusual diversity of nucleotidyltransferase genes is not restricted to Acanthamoeba castellanii but is also present in other members of the Acanthamoeba genus, indicating an ancient evolutionary trait.
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Affiliation(s)
- Lieselotte Erber
- Institute for Biochemistry, Leipzig University, Leipzig, Germany
| | - Heike Betat
- Institute for Biochemistry, Leipzig University, Leipzig, Germany
| | - Mario Mörl
- Institute for Biochemistry, Leipzig University, Leipzig, Germany
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44
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Fu MS, Liporagi-Lopes LC, Dos Santos SR, Tenor JL, Perfect JR, Cuomo CA, Casadevall A. Amoeba Predation of Cryptococcus neoformans Results in Pleiotropic Changes to Traits Associated with Virulence. mBio 2021; 12:e00567-21. [PMID: 33906924 PMCID: PMC8092252 DOI: 10.1128/mbio.00567-21] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 03/30/2021] [Indexed: 11/20/2022] Open
Abstract
Amoeboid predators, such as amoebae, are proposed to select for survival traits in soil microbes such as Cryptococcus neoformans; these traits can also function in animal virulence by defeating phagocytic immune cells, such as macrophages. Consistent with this notion, incubation of various fungal species with amoebae enhanced their virulence, but the mechanisms involved are unknown. In this study, we exposed three strains of C. neoformans (1 clinical and 2 environmental) to predation by Acanthamoeba castellanii for prolonged times and then analyzed surviving colonies phenotypically and genetically. Surviving colonies comprised cells that expressed either pseudohyphal or yeast phenotypes, which demonstrated variable expression of traits associated with virulence, such as capsule size, urease production, and melanization. Phenotypic changes were associated with aneuploidy and DNA sequence mutations in some amoeba-passaged isolates, but not in others. Mutations in the gene encoding the oligopeptide transporter (CNAG_03013; OPT1) were observed among amoeba-passaged isolates from each of the three strains. Isolates derived from environmental strains gained the capacity for enhanced macrophage toxicity after amoeba selection and carried mutations on the CNAG_00570 gene encoding Pkr1 (AMP-dependent protein kinase regulator) but manifested reduced virulence in mice because they elicited more effective fungal-clearing immune responses. Our results indicate that C. neoformans survival under constant amoeba predation involves the generation of strains expressing pleiotropic phenotypic and genetic changes. Given the myriad potential predators in soils, the diversity observed among amoeba-selected strains suggests a bet-hedging strategy whereby variant diversity increases the likelihood that some will survive predation.IMPORTANCECryptococcus neoformans is a ubiquitous environmental fungus that is also a leading cause of fatal fungal infection in humans, especially among immunocompromised patients. A major question in the field is how an environmental yeast such as C. neoformans becomes a human pathogen when it has no need for an animal host in its life cycle. Previous studies showed that C. neoformans increases its pathogenicity after interacting with its environmental predator amoebae. Amoebae, like macrophages, are phagocytic cells that are considered an environmental training ground for pathogens to resist macrophages, but the mechanism by which C. neoformans changes its virulence through interactions with protozoa is unknown. Our study indicates that fungal survival in the face of amoeba predation is associated with the emergence of pleiotropic phenotypic and genomic changes that increase the chance of fungal survival, with this diversity suggesting a bet-hedging strategy to ensure that some forms survive.
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Affiliation(s)
- Man Shun Fu
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Livia C Liporagi-Lopes
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Samuel R Dos Santos
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Jennifer L Tenor
- Division of Infectious Diseases, Department of Medicine and Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, USA
| | - John R Perfect
- Division of Infectious Diseases, Department of Medicine and Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, USA
| | - Christina A Cuomo
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
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Kunze M, Steiner T, Chen F, Huber C, Rydzewski K, Stämmler M, Heuner K, Eisenreich W. Metabolic adaption of Legionella pneumophila during intracellular growth in Acanthamoeba castellanii. Int J Med Microbiol 2021; 311:151504. [PMID: 33906075 DOI: 10.1016/j.ijmm.2021.151504] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/19/2021] [Accepted: 04/15/2021] [Indexed: 11/15/2022] Open
Abstract
The metabolism of Legionella pneumophila strain Paris was elucidated during different time intervals of growth within its natural host Acanthamoeba castellanii. For this purpose, the amoebae were supplied after bacterial infection (t =0 h) with 11 mM [U-13C6]glucose or 3 mM [U-13C3]serine, respectively, during 0-17 h, 17-25 h, or 25-27 h of incubation. At the end of these time intervals, bacterial and amoebal fractions were separated. Each of these fractions was hydrolyzed under acidic conditions. 13C-Enrichments and isotopologue distributions of resulting amino acids and 3-hydroxybutyrate were determined by gas chromatography - mass spectrometry. Comparative analysis of the labelling patterns revealed the substrate preferences, metabolic pathways, and relative carbon fluxes of the intracellular bacteria and their amoebal host during the time course of the infection cycle. Generally, the bacterial infection increased the usage of exogenous glucose via glycolysis by A. castellanii. In contrast, carbon fluxes via the amoebal citrate cycle were not affected. During the whole infection cycle, intracellular L. pneumophila incorporated amino acids from their host into the bacterial proteins. However, partial bacterial de novo biosynthesis from exogenous 13C-Ser and, at minor rates, from 13C-glucose could be shown for bacterial Ala, Asp, Glu, and Gly. More specifically, the catabolic usage of Ser increased during the post-exponential phase of intracellular growth, whereas glucose was utilized by the bacteria throughout the infection cycle and not only late during infection as assumed on the basis of earlier in vitro experiments. The early usage of 13C-glucose by the intracellular bacteria suggests that glucose availability could serve as a trigger for replication of L. pneumophila inside the vacuoles of host cells.
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Affiliation(s)
- Mareike Kunze
- Working Group: Cellular Interactions of Bacterial Pathogens, Centre for Biological Threats and Special Pathogens, ZBS 2, Robert Koch Institute, Berlin, Germany
| | - Thomas Steiner
- Bavarian NMR Center - Structural Membrane Biochemistry, Department of Chemistry, Technische Universität München, Garching, Germany
| | - Fan Chen
- Bavarian NMR Center - Structural Membrane Biochemistry, Department of Chemistry, Technische Universität München, Garching, Germany
| | - Claudia Huber
- Bavarian NMR Center - Structural Membrane Biochemistry, Department of Chemistry, Technische Universität München, Garching, Germany
| | - Kerstin Rydzewski
- Working Group: Cellular Interactions of Bacterial Pathogens, Centre for Biological Threats and Special Pathogens, ZBS 2, Robert Koch Institute, Berlin, Germany
| | - Maren Stämmler
- Proteomics and Spectroscopy, ZBS 6, Robert Koch Institute, Berlin, Germany
| | - Klaus Heuner
- Working Group: Cellular Interactions of Bacterial Pathogens, Centre for Biological Threats and Special Pathogens, ZBS 2, Robert Koch Institute, Berlin, Germany.
| | - Wolfgang Eisenreich
- Bavarian NMR Center - Structural Membrane Biochemistry, Department of Chemistry, Technische Universität München, Garching, Germany.
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Allegro AR, Barhoumi R, Bordin AI, Bray JM, Cohen ND. Uptake and replication in Acanthamoeba castellanii of a virulent (pVAPA-positive) strain of Rhodococcus equi and its isogenic, plasmid-cured strain. Vet Microbiol 2021; 257:109069. [PMID: 33862330 DOI: 10.1016/j.vetmic.2021.109069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 04/07/2021] [Indexed: 11/16/2022]
Abstract
Rhodococcus equi is a soil saprophytic bacterium and intracellular pathogen that causes pneumonia in foals. Strains of R. equi that are virulent in foals contain a plasmid that encodes a virulence-associated protein A (VapA) necessary for replication in macrophages. Because other intracellular pathogens survive and replicate inside amoebae, we postulated that the VapA-bearing plasmid (pVAPA) confers a survival advantage for R. equi against environmental predators like amoebae. To test this hypothesis, we compared phagocytosis by and survival in Acanthamoeba castellanii of isogenic strains of pVAPA-positive and pVAPA-negative R. equi. Phagocytosis of the pVAPA-negative strain by A. castellanii was significantly (P < 0.0001) greater than the pVAPA-positive strain. Intracellular replication of the pVAPA-positive strain in A. castellanii was significantly (P < 0.0001) greater than the pVAPA-negative strain during both 48 h and 9 days. These results indicate that the presence of the VapA plasmid reduces uptake and aids replication of R. equi in A. castellanii.
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Affiliation(s)
- Angelica R Allegro
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, 77843-4475, United States
| | - Rola Barhoumi
- Image Analysis Laboratory, Department of Veterinary Integrative Biosciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, 77843-4458, United States
| | - Angela I Bordin
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, 77843-4475, United States
| | - Jocelyne M Bray
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, 77843-4475, United States
| | - Noah D Cohen
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, 77843-4475, United States.
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Leitsch D, Mbouaka AL, Köhsler M, Müller N, Walochnik J. An unusual thioredoxin system in the facultative parasite Acanthamoeba castellanii. Cell Mol Life Sci 2021; 78:3673-3689. [PMID: 33599799 PMCID: PMC8038987 DOI: 10.1007/s00018-021-03786-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/08/2021] [Accepted: 02/02/2021] [Indexed: 01/25/2023]
Abstract
The free-living amoeba Acanthamoeba castellanii occurs worldwide in soil and water and feeds on bacteria and other microorganisms. It is, however, also a facultative parasite and can cause serious infections in humans. The annotated genome of A. castellanii (strain Neff) suggests the presence of two different thioredoxin reductases (TrxR), of which one is of the small bacterial type and the other of the large vertebrate type. This combination is highly unusual. Similar to vertebrate TrxRases, the gene coding for the large TrxR in A. castellanii contains a UGA stop codon at the C-terminal active site, suggesting the presence of selenocysteine. We characterized the thioredoxin system in A. castellanii in conjunction with glutathione reductase (GR), to obtain a more complete understanding of the redox system in A. castellanii and the roles of its components in the response to oxidative stress. Both TrxRases localize to the cytoplasm, whereas GR localizes to the cytoplasm and the large organelle fraction. We could only identify one thioredoxin (Trx-1) to be indeed reduced by one of the TrxRases, i.e., by the small TrxR. This thioredoxin, in turn, could reduce one of the two peroxiredoxins tested and also methionine sulfoxide reductase A (MsrA). Upon exposure to hydrogen peroxide and diamide, only the small TrxR was upregulated in expression at the mRNA and protein levels, but not the large TrxR. Our results show that the small TrxR is involved in the A. castellanii's response to oxidative stress. The role of the large TrxR, however, remains elusive.
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Affiliation(s)
- David Leitsch
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Kinderspitalgasse 15, 1090, Vienna, Austria.
| | - Alvie Loufouma Mbouaka
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Kinderspitalgasse 15, 1090, Vienna, Austria
| | - Martina Köhsler
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Kinderspitalgasse 15, 1090, Vienna, Austria
| | - Norbert Müller
- Institute of Parasitology, Vetsuisse Faculty, University of Bern, Länggassstrasse 122, 3012, Bern, Switzerland
| | - Julia Walochnik
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Kinderspitalgasse 15, 1090, Vienna, Austria
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Head BM, Graham CI, MacMartin T, Keynan Y, Brassinga AKC. Development of a Fluorescent Tool for Studying Legionella bozemanae Intracellular Infection. Microorganisms 2021; 9:379. [PMID: 33668592 PMCID: PMC7917989 DOI: 10.3390/microorganisms9020379] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/08/2021] [Accepted: 02/11/2021] [Indexed: 01/14/2023] Open
Abstract
Legionnaires' disease incidence is on the rise, with the majority of cases attributed to the intracellular pathogen, Legionella pneumophila. Nominally a parasite of protozoa, L. pneumophila can also infect alveolar macrophages when bacteria-laden aerosols enter the lungs of immunocompromised individuals. L. pneumophila pathogenesis has been well characterized; however, little is known about the >25 different Legionella spp. that can cause disease in humans. Here, we report for the first time a study demonstrating the intracellular infection of an L. bozemanae clinical isolate using approaches previously established for L. pneumophila investigations. Specifically, we report on the modification and use of a green fluorescent protein (GFP)-expressing plasmid as a tool to monitor the L. bozemanae presence in the Acanthamoeba castellanii protozoan infection model. As comparative controls, L. pneumophila strains were also transformed with the GFP-expressing plasmid. In vitro and in vivo growth kinetics of the Legionella parental and GFP-expressing strains were conducted followed by confocal microscopy. Results suggest that the metabolic burden imposed by GFP expression did not impact cell viability, as growth kinetics were similar between the GFP-expressing Legionella spp. and their parental strains. This study demonstrates that the use of a GFP-expressing plasmid can serve as a viable approach for investigating Legionella non-pneumophila spp. in real time.
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Affiliation(s)
- Breanne M. Head
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB R3T 2N2, Canada;
| | - Christopher I. Graham
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada; (C.I.G.); (T.M.); (A.K.C.B.)
| | - Teassa MacMartin
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada; (C.I.G.); (T.M.); (A.K.C.B.)
| | - Yoav Keynan
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB R3T 2N2, Canada;
| | - Ann Karen C. Brassinga
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada; (C.I.G.); (T.M.); (A.K.C.B.)
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Wang Z, Wu D, Tachibana H, Feng M, Cheng XJ. Identification and biochemical characterisation of Acanthamoeba castellanii cysteine protease 3. Parasit Vectors 2020; 13:592. [PMID: 33228764 PMCID: PMC7685649 DOI: 10.1186/s13071-020-04474-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 11/05/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Acanthamoeba spp. are free-living amoeba that are ubiquitously distributed in the environment. This study examines pathogenic Acanthamoeba cysteine proteases (AcCPs) belonging to the cathepsin L-family and explores the mechanism of AcCP3 interaction with host cells. METHODS Six AcCP genes were amplified by polymerase chain reaction (PCR). Quantitative real-time PCR was used to analyse the relative mRNA expression of AcCPs during the encystation process and between pre- and post-reactivated trophozoites. To further verify the role of AcCP3 in these processes, AcCP3 recombinant proteins were expressed in Escherichia coli, and the hydrolytic activity of AcCP3 was determined. The influence of the AcCP3 on the hydrolytic activity of trophozoites and the toxicity of trophozoites to human corneal epithelial cells (HCECs) was examined by inhibiting AcCP3 expression using siRNA. Furthermore, the levels of p-Raf and p-Erk were examined in HCECs following coculture with AcCP3 gene knockdown trophozoites by Western blotting. RESULTS During encystation, five out of six AcCPs exhibited decreased expression, and only AcCP6 was substantially up-regulated at the mRNA level, indicating that most AcCPs were not directly correlated to encystation. Furthermore, six AcCPs exhibited increased expression level following trophozoite reactivation with HEp-2 cells, particularly AcCP3, indicating that these AcCPs might be virulent factors. After refolding of recombinant AcCP3 protein, the 27 kDa mature protein from the 34 kDa pro-protein hydrolysed host haemoglobin, collagen and albumin and showed high activity in an acidic environment. After AcCP3 knockdown, the hydrolytic activity of trophozoite crude protein against gelatin was decreased, suggesting that these trophozoites had decreased toxicity. Compared with untreated trophozoites or negative control siRNA-treated trophozoites, AcCP3-knockdown trophozoites were less able to penetrate and damage monolayers of HCECs. Western blot analysis showed that the activation levels of the Ras/Raf/Erk/p53 signalling pathways in HCECs decreased after inhibiting the expression of trophozoite AcCP3. CONCLUSIONS AcCP6 was correlated to encystation. Furthermore, AcCP3 was a virulent factor in trophozoites and participated in the activation of the Ras/Raf/Erk/p53 signalling pathways of host cells.
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Affiliation(s)
- Zhixin Wang
- Department of Medical Microbiology and Parasitology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Duo Wu
- Department of Medical Microbiology and Parasitology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Hiroshi Tachibana
- Department of Infectious Diseases, Tokai University School of Medicine, Isehara, Kanagawa, 259-1193, Japan
| | - Meng Feng
- Department of Medical Microbiology and Parasitology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China.
| | - Xun-Jia Cheng
- Department of Medical Microbiology and Parasitology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China.
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Latifi A, Salimi M. Growth comparison of Acanthamoeba genotypes T3 and T4 in several culture media. Heliyon 2020; 6:e04805. [PMID: 32984575 PMCID: PMC7494459 DOI: 10.1016/j.heliyon.2020.e04805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 05/07/2019] [Accepted: 08/24/2020] [Indexed: 11/18/2022] Open
Abstract
Acanthamoeba causes severe diseases such as Granulomatous Amebic Encephalitis (GAE) and Acanthamoeba keratitis (AK). Improving the culture media classically used for this amoeba could help to identify it quickly and facilitate its study as a biological model. The purpose of this study was to compare the growth of two Acanthamoeba genotypes (T3 and T4) in several culture media. Acanthamoeba griffini (T3 genotype) and Acanthamoeba castellanii (T4 genotype) were cultured in PYG, TSY, TYI-S-33, RPMI, and RPMI-FBS medium. The number of amoebas grown in different culture media was counted and compared to each other for 14 days. Findings in this research revealed the highest growth in RPMI-FBS medium. For this reason, we can recommend this culture medium to promote the growth of Acanthamoeba in its biological studies.
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