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Lê HG, Kang JM, Võ TC, Yoo WG, Hong Y, Na BK. (‒)-Epicatechin reveals amoebicidal activity against Acanthamoeba castellanii by activating the programmed cell death pathway. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2024; 125:155389. [PMID: 38306720 DOI: 10.1016/j.phymed.2024.155389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 12/28/2023] [Accepted: 01/24/2024] [Indexed: 02/04/2024]
Abstract
BACKGROUND Acanthamoeba is an opportunistic pathogen that can cause human infections such as granulomatous amebic encephalitis and acanthamoeba keratitis. However, no specific drug to treat the diseases has been developed. Therefore, the discovery or development of novel drugs for treating Acanthamoeba infections is urgently needed. The anti-protozoan activity of (‒)-epicatechin (EC) has been reported, suggesting it is an attractive anti-protozoal drug candidate. In this study, the amoebicidal activity of EC against A. castellanii was assessed and its mechanism of action was unveiled. METHODS The amoebicidal activity of EC against A. castellanii trophozoites and the cytotoxicity of EC in HCE-2 and C6 cells were determined with cell viability assay. The underlying amoebicidal mechanism of EC against A. castellanii was analyzed by the apoptosis/necrosis assay, TUNEL assay, mitochondrial dysfunction assay, caspase-3 assay, and quantitative reverse transcription polymerase chain reaction. The cysticidal activity of EC was also investigated. RESULTS EC revealed amoebicidal activity against A. castellanii trophozoites with an IC50 of 37.01 ± 3.96 µM, but was not cytotoxic to HCE-2 or C6 cells. EC induced apoptotic events such as increases in DNA fragmentation and intracellular reactive oxygen species production in A. castellanii. EC also caused mitochondrial dysfunction in the amoebae, as evidenced by the loss of mitochondrial membrane potential and reductions in ATP production. Caspase-3 activity, autophagosome formation, and the expression levels of autophagy-related genes were also increased in EC-treated amoebae. EC led to the partial death of cysts and the inhibition of excystation. CONCLUSION EC revealed promising amoebicidal activity against A. castellanii trophozoites via programmed cell death events. EC could be a candidate drug or supplemental compound for treating Acanthamoeba infections.
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Affiliation(s)
- Hương Giang Lê
- Department of Parasitology and Tropical Medicine, and Institute of Health Science, Gyeongsang National University College of Medicine, Jinju, 52727, Korea; Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Korea
| | - Jung-Mi Kang
- Department of Parasitology and Tropical Medicine, and Institute of Health Science, Gyeongsang National University College of Medicine, Jinju, 52727, Korea; Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Korea
| | - Tuấn Cường Võ
- Department of Parasitology and Tropical Medicine, and Institute of Health Science, Gyeongsang National University College of Medicine, Jinju, 52727, Korea; Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Korea
| | - Won Gi Yoo
- Department of Parasitology and Tropical Medicine, and Institute of Health Science, Gyeongsang National University College of Medicine, Jinju, 52727, Korea; Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Korea
| | - Yeonchul Hong
- Department of Parasitology and Tropical Medicine, School of Medicine, Kyungpook National University, Daegu, 41944, Korea
| | - Byoung-Kuk Na
- Department of Parasitology and Tropical Medicine, and Institute of Health Science, Gyeongsang National University College of Medicine, Jinju, 52727, Korea; Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Korea.
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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] [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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Bandyopadhyay A, Ghosh SK. Role of autophagy in stress and drug-responsive cell death in Entamoeba histolytica and its cross-talk with apoptosis-inducing factor. Mol Biochem Parasitol 2023; 256:111593. [PMID: 37708914 DOI: 10.1016/j.molbiopara.2023.111593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 09/03/2023] [Accepted: 09/11/2023] [Indexed: 09/16/2023]
Abstract
Cell death in unicellular protozoan parasite Entamoeba histolytica is not yet reported though it displays several features of autophagic cell death. Autophagic cell death was reported to take place in ancient protozoans under several stresses. Here we report the occurrence of autophagic cell death in the Entamoeba histolytica trophozoites under oxidative stress as well as by the treatment with metronidazole, the most-widely-used drug for amoebiasis treatment and was shown to generate oxidative stress in the trophozoites. The autophagic flux increases during nutrient deprivation and metronidazole treatment and decreases upon oxidative stress. During oxidative stress the autophagy leads to nucleophagy that is ultimately destined to be digested within the lysosomal chamber. The formation of nucleophagosome depends on the apoptosis-inducing factor (AIF) that translocates to the nucleus from cytoplasm upon oxidative stress. It was experimentally proved that ATG8 (Autophagy-related protein 8) binds with the AIF in the nucleus of the trophozoites and helps in ATG8 recruitment and autophagy initiation overall suggesting that oxidative stress-driven AIF translocation to nucleus results in binding with ATG8 and initiates nucleophagy leading to cell death.
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Affiliation(s)
| | - Sudip Kumar Ghosh
- Department of Biotechnology, IIT Kharagpur, West Bengal 721302, India.
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Samba-Louaka A, Labruyère E, Matondo M, Locard-Paulet M, Olivo-Marin JC, Guillen N. Encystation and Stress Responses under the Control of Ubiquitin-like Proteins in Pathogenic Amoebae. Microorganisms 2023; 11:2670. [PMID: 38004682 PMCID: PMC10673212 DOI: 10.3390/microorganisms11112670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 10/21/2023] [Accepted: 10/24/2023] [Indexed: 11/26/2023] Open
Abstract
Amoebae found in aquatic and terrestrial environments encompass various pathogenic species, including the parasite Entamoeba histolytica and the free-living Acanthamoeba castellanii. Both microorganisms pose significant threats to public health, capable of inducing life-threatening effects on humans. These amoebae exist in two cellular forms: trophozoites and cysts. The trophozoite stage is the form used for growth and reproduction while the cyst stage is the resistant and disseminating form. Cysts occur after cellular metabolism slowdown due to nutritional deprivation or the appearance of environmental conditions unfavourable to the amoebae's growth and division. The initiation of encystation is accompanied by the activation of stress responses, and scarce data indicate that encystation shares factors and mechanisms identified in stress responses occurring in trophozoites exposed to toxic compounds derived from human immune defence. Although some "omics" analyses have explored how amoebae respond to diverse stresses, these studies remain limited and rarely report post-translational modifications that would provide knowledge on the molecular mechanisms underlying amoebae-specific stress responses. In this review, we discuss ubiquitin-like proteins associated with encystation and cell survival during oxidative damage. We aim to shed light on the signalling pathways involved in amoebic defence mechanisms, with a focus on their potential clinical implications against pathogenic amoebae, addressing the pressing need for effective therapies.
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Affiliation(s)
- Ascel Samba-Louaka
- Université de Poitiers, Centre National de la Recherche Scientifique UMR7267, Laboratoire Ecologie et Biologie des Interactions, TSA51106, 86073 Poitiers, France
| | - Elisabeth Labruyère
- Institut Pasteur, Biological Image Analysis Unit, Centre National de la Recherche Scientifique UMR3691, Université Paris Cité, 75015 Paris, France; (E.L.); (J.-C.O.-M.)
| | - Mariette Matondo
- Institut Pasteur, Proteomics Core Facility, Mass Spectrometry for Biology Unit, Centre National de la Recherche Scientifique UAR 2024, Université Paris Cité, 75015 Paris, France;
| | - Marie Locard-Paulet
- Institut de Pharmacologie et de Biologie Structurale, Centre National de la Recherche Scientifique UMR 5089, Université Toulouse III-Paul Sabatier, 31077 Toulouse, France;
- Infrastructure Nationale de Proteomique ProFI—FR2048, 2048 Toulouse, France
| | - Jean-Christophe Olivo-Marin
- Institut Pasteur, Biological Image Analysis Unit, Centre National de la Recherche Scientifique UMR3691, Université Paris Cité, 75015 Paris, France; (E.L.); (J.-C.O.-M.)
| | - Nancy Guillen
- Institut Pasteur, Biological Image Analysis Unit, Centre National de la Recherche Scientifique UMR3691, Université Paris Cité, 75015 Paris, France; (E.L.); (J.-C.O.-M.)
- Institut Pasteur, Centre National de la Recherche Scientifique ERL9195, 75015 Paris, France
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Lê HG, Kang JM, Võ TC, Na BK. Kaempferol induces programmed cell death in Naegleria fowleri. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2023; 119:154994. [PMID: 37597363 DOI: 10.1016/j.phymed.2023.154994] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/21/2023] [Accepted: 07/22/2023] [Indexed: 08/21/2023]
Abstract
BACKGROUND Naegleria fowleri is a brain-eating amoeba causing a fatal brain infection called primary amoebic meningoencephalitis (PAM). Despite its high mortality over 95%, effective therapeutic drug for PAM has not been developed yet. Therefore, development of an effective and safe therapeutic drug for PAM is urgently needed. In this study, we investigated anti-amoebic effect of kaempferol (KPF) against N. fowleri and its underlying anti-amoebic molecular mechanisms. METHODS Anti-amoebic activity of KPF against N. fowleri trophozoites, as well as cytotoxicity of KPF in C6 glial cells and CHO-K1 cells were investigated. The programmed cell death mechanisms in KPF-treated N. fowleri were also analyzed by apoptosis-necrosis assay, mitochondrial dysfunction assay, TUNEL assay, RT-qPCR, and CYTO-ID assay. RESULTS KPF showed anti-amoebic activity against N. fowleri trophozoites with an IC50 of 29.28 ± 0.63 μM. However, it showed no significant cytotoxicity to mammalian cells. KPF induced significant morphological alterations of the amoebae, resulting in death. Signals associated with apoptosis were detected in the amoebae upon treatment with KPF. KPF induced an increase of intracellular reactive oxygen species level, loss of mitochondrial membrane potential, increases of expression levels of genes associated with mitochondria dysfunction, and reduction of ATP levels in the amoebae. Autophagic vacuole accumulations with increased expression levels of autophagy-related genes were also detected in KPF-treated amoebae. CONCLUSION KPF induces programmed cell death in N. fowleri trophozoites via apoptosis-like pathway and autophagy pathway. KPF could be used as a candidate of anti-amoebic drug or supplement compound in the process of developing or optimizing therapeutic drug for PAM.
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Affiliation(s)
- Hương Giang Lê
- Department of Parasitology and Tropical Medicine, Institute of Health Science, Gyeongsang National University College of Medicine, Jinju 52727, Korea; Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Korea
| | - Jung-Mi Kang
- Department of Parasitology and Tropical Medicine, Institute of Health Science, Gyeongsang National University College of Medicine, Jinju 52727, Korea; Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Korea
| | - Tuấn Cường Võ
- Department of Parasitology and Tropical Medicine, Institute of Health Science, Gyeongsang National University College of Medicine, Jinju 52727, Korea; Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Korea
| | - Byoung-Kuk Na
- Department of Parasitology and Tropical Medicine, Institute of Health Science, Gyeongsang National University College of Medicine, Jinju 52727, Korea; Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Korea.
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Ayilam Ramachandran R, Sanches JM, Robertson DM. The roles of autophagy and mitophagy in corneal pathology: current knowledge and future perspectives. Front Med (Lausanne) 2023; 10:1064938. [PMID: 37153108 PMCID: PMC10160402 DOI: 10.3389/fmed.2023.1064938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Accepted: 01/16/2023] [Indexed: 05/09/2023] Open
Abstract
The cornea is the clear dome that covers the front portion of the globe. The primary functions of the cornea are to promote the refraction of light and to protect the eye from invading pathogens, both of which are essential for the preservation of vision. Homeostasis of each cellular layer of the cornea requires the orchestration of multiple processes, including the ability to respond to stress. One mechanism whereby cells respond to stress is autophagy, or the process of "self-eating." Autophagy functions to clear damaged proteins and organelles. During nutrient deprivation, amino acids released from protein breakdown via autophagy are used as a fuel source. Mitophagy, a selective form of autophagy, functions to clear damaged mitochondria. Thus, autophagy and mitophagy are important intracellular degradative processes that sustain tissue homeostasis. Importantly, the inhibition or excessive activation of these processes result in deleterious effects on the cell. In the eye, impairment or inhibition of these mechanisms have been associated with corneal disease, degenerations, and dystrophies. This review summarizes the current body of knowledge on autophagy and mitophagy at all layers in the cornea in both non-infectious and infectious corneal disease, dystrophies, and degenerations. It further highlights the critical gaps in our understanding of mitochondrial dysfunction, with implications for novel therapeutics in clinical practice.
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Affiliation(s)
| | - Jose Marcos Sanches
- Department of Ophthalmology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Danielle M Robertson
- Department of Ophthalmology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
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de Obeso Fernández Del Valle A, Scheckhuber CQ, Chavaro-Pérez DA, Ortega-Barragán E, Maciver SK. mRNA Sequencing Reveals Upregulation of Glutathione S-Transferase Genes during Acanthamoeba Encystation. Microorganisms 2023; 11:992. [PMID: 37110414 PMCID: PMC10142586 DOI: 10.3390/microorganisms11040992] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/04/2023] [Accepted: 04/05/2023] [Indexed: 04/29/2023] Open
Abstract
Some members of the genus Acanthamoeba are facultative pathogens typically with a biphasic lifestyle: trophozoites and cysts. Acanthamoeba is capable of infecting the cornea, resulting in Acanthamoeba keratitis. The cyst is one of the key components for the persistence of infection. Gene expression during Acanthamoeba encystation showed an upregulation of glutathione S-transferase (GST) genes and other closely related proteins. mRNA sequencing showed GST, and five genes with similar sequences were upregulated after 24 h of inducing encystation. GST overexpression was verified with qPCR using the HPRT and the cyst-specific protein 21 genes as controls. The GST inhibitor ethacrynic acid was found to decrease cell viability by 70%. These results indicate a role of GST in successful encystation, possibly by maintaining redox balance. GST and associated processes could be targets for potential treatments alongside regular therapies to reduce relapses of Acanthamoeba infection.
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Affiliation(s)
- Alvaro de Obeso Fernández Del Valle
- Departamento de Bioingeniería, Escuela de Ingeniería y Ciencias, Tecnologico de Monterrey, Ave. Eugenio Garza Sada 2501, Monterrey 64849, Nuevo León, Mexico
| | - Christian Quintus Scheckhuber
- Departamento de Bioingeniería, Escuela de Ingeniería y Ciencias, Tecnologico de Monterrey, Ave. Eugenio Garza Sada 2501, Monterrey 64849, Nuevo León, Mexico
| | - David Armando Chavaro-Pérez
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Ave. Eugenio Garza Sada 2501, Monterrey 64849, Nuevo León, Mexico
| | - Erandi Ortega-Barragán
- Departamento de Bioingeniería, Escuela de Ingeniería y Ciencias, Tecnologico de Monterrey, Ave. Eugenio Garza Sada 2501, Monterrey 64849, Nuevo León, 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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Romano PS, Akematsu T, Besteiro S, Bindschedler A, Carruthers VB, Chahine Z, Coppens I, Descoteaux A, Alberto Duque TL, He CY, Heussler V, Le Roch KG, Li FJ, de Menezes JPB, Menna-Barreto RFS, Mottram JC, Schmuckli-Maurer J, Turk B, Tavares Veras PS, Salassa BN, Vanrell MC. Autophagy in protists and their hosts: When, how and why? AUTOPHAGY REPORTS 2023; 2:2149211. [PMID: 37064813 PMCID: PMC10104450 DOI: 10.1080/27694127.2022.2149211] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 11/15/2022] [Indexed: 03/12/2023]
Abstract
Pathogenic protists are a group of organisms responsible for causing a variety of human diseases including malaria, sleeping sickness, Chagas disease, leishmaniasis, and toxoplasmosis, among others. These diseases, which affect more than one billion people globally, mainly the poorest populations, are characterized by severe chronic stages and the lack of effective antiparasitic treatment. Parasitic protists display complex life-cycles and go through different cellular transformations in order to adapt to the different hosts they live in. Autophagy, a highly conserved cellular degradation process, has emerged as a key mechanism required for these differentiation processes, as well as other functions that are crucial to parasite fitness. In contrast to yeasts and mammals, protist autophagy is characterized by a modest number of conserved autophagy-related proteins (ATGs) that, even though, can drive the autophagosome formation and degradation. In addition, during their intracellular cycle, the interaction of these pathogens with the host autophagy system plays a crucial role resulting in a beneficial or harmful effect that is important for the outcome of the infection. In this review, we summarize the current state of knowledge on autophagy and other related mechanisms in pathogenic protists and their hosts. We sought to emphasize when, how, and why this process takes place, and the effects it may have on the parasitic cycle. A better understanding of the significance of autophagy for the protist life-cycle will potentially be helpful to design novel anti-parasitic strategies.
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Affiliation(s)
- Patricia Silvia Romano
- Laboratorio de Biología de Trypanosoma cruzi y de la célula hospedadora. Instituto de Histología y Embriología de Mendoza. Universidad Nacional de Cuyo. (IHEM-CONICET-UNCUYO). Facultad de Ciencias Médicas. Universidad Nacional de Cuyo. Av. Libertador 80 (5500), Mendoza, Argentina
| | - Takahiko Akematsu
- Department of Biosciences, College of Humanities and Sciences, Nihon University, Tokyo, Japan
| | | | | | - Vern B Carruthers
- Department of Microbiology and Immunology, University of Michigan School of Medicine, Ann Arbor, MI, USA
| | - Zeinab Chahine
- Department of Molecular, Cell and Systems Biology, University of California Riverside, CA, USA
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology. Department of Molecular Microbiology and Immunology. Johns Hopkins Malaria Research Institute. Johns Hopkins University Bloomberg School of Public Health. Baltimore 21205, MD, USA
| | - Albert Descoteaux
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique, Laval, QC
| | - Thabata Lopes Alberto Duque
- Autophagy Inflammation and Metabolism Center, University of New Mexico Health Sciences Center, Albuquerque, NM, USA; Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Cynthia Y He
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Volker Heussler
- Institute of Cell Biology.University of Bern. Baltzerstr. 4 3012 Bern
| | - Karine G Le Roch
- Department of Molecular, Cell and Systems Biology, University of California Riverside, CA, USA
| | - Feng-Jun Li
- Department of Biological Sciences, National University of Singapore, Singapore
| | | | | | - Jeremy C Mottram
- York Biomedical Research Institute, Department of Biology, University of York, York, UK
| | | | - Boris Turk
- Department of Biochemistry and Molecular and Structural Biology, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
| | - Patricia Sampaio Tavares Veras
- Laboratory of Host-Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Fiocruz-Bahia
- National Institute of Science and Technology of Tropical Diseases - National Council for Scientific Research and Development (CNPq)
| | - Betiana Nebai Salassa
- Laboratorio de Biología de Trypanosoma cruzi y de la célula hospedadora. Instituto de Histología y Embriología de Mendoza. Universidad Nacional de Cuyo. (IHEM-CONICET-UNCUYO). Facultad de Ciencias Médicas. Universidad Nacional de Cuyo. Av. Libertador 80 (5500), Mendoza, Argentina
| | - María Cristina Vanrell
- Laboratorio de Biología de Trypanosoma cruzi y de la célula hospedadora. Instituto de Histología y Embriología de Mendoza. Universidad Nacional de Cuyo. (IHEM-CONICET-UNCUYO). Facultad de Ciencias Médicas. Universidad Nacional de Cuyo. Av. Libertador 80 (5500), Mendoza, Argentina
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Wang Y, Jiang L, Zhao Y, Ju X, Wang L, Jin L, Fine RD, Li M. Biological characteristics and pathogenicity of Acanthamoeba. Front Microbiol 2023; 14:1147077. [PMID: 37089530 PMCID: PMC10113681 DOI: 10.3389/fmicb.2023.1147077] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 03/21/2023] [Indexed: 04/25/2023] Open
Abstract
Acanthamoeba is an opportunistic protozoa, which exists widely in nature and is mainly distributed in soil and water. Acanthamoeba usually exists in two forms, trophozoites and cysts. The trophozoite stage is one of growth and reproduction while the cyst stage is characterized by cellular quiescence, commonly resulting in human infection, and the lack of effective monotherapy after initial infection leads to chronic disease. Acanthamoeba can infect several human body tissues such as the skin, cornea, conjunctiva, respiratory tract, and reproductive tract, especially when the tissue barriers are damaged. Furthermore, serious infections can cause Acanthamoeba keratitis, granulomatous amoebic encephalitis, skin, and lung infections. With an increasing number of Acanthamoeba infections in recent years, the pathogenicity of Acanthamoeba is becoming more relevant to mainstream clinical care. This review article will describe the etiological characteristics of Acanthamoeba infection in detail from the aspects of biological characteristic, classification, disease, and pathogenic mechanism in order to provide scientific basis for the diagnosis, treatment, and prevention of Acanthamoeba infection.
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Affiliation(s)
- Yuehua Wang
- College of Laboratory Medicine, Jilin Medical University, Jilin City, China
| | - Linzhe Jiang
- General Surgery, Jilin People’s Hospital, Jilin City, China
| | - Yitong Zhao
- College of Laboratory Medicine, Jilin Medical University, Jilin City, China
| | - Xiaohong Ju
- College of Laboratory Medicine, Jilin Medical University, Jilin City, China
| | - Le Wang
- Department of Laboratory Medicine, Jilin Hospital of Integrated Chinese and Western Medicine, Jilin City, China
| | - Liang Jin
- Department of Laboratory Medicine, Jilin Hospital of Integrated Chinese and Western Medicine, Jilin City, China
| | - Ryan D. Fine
- Center for Human Genetics and Genomics, New York University Grossman School of Medicine, New York City, NY, United States
| | - Mingguang Li
- College of Laboratory Medicine, Jilin Medical University, Jilin City, China
- *Correspondence: Mingguang Li,
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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, SWITZERLAND) 2022; 11:3459. [PMID: 36559571 PMCID: PMC9783201 DOI: 10.3390/plants11243459] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [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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11
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Fechtali-Moute Z, Loiseau PM, Pomel S. Stimulation of Acanthamoeba castellanii excystment by enzyme treatment and consequences on trophozoite growth. Front Cell Dev Biol 2022; 10:982897. [PMID: 36172275 PMCID: PMC9511172 DOI: 10.3389/fcell.2022.982897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/17/2022] [Indexed: 11/13/2022] Open
Abstract
Acanthamoeba castellanii is a widespread Free-Living Amoeba (FLA) that can cause severe ocular or cerebral infections in immunocompetent and immunocompromised patients, respectively, besides its capacity to transport diverse pathogens. During their life cycle, FLA can alternate between a vegetative form, called a trophozoite, and a latent and resistant form, called a cyst. This resistant form is characterized by the presence of a cell wall containing two layers, namely the ectocyst and the endocyst, mainly composed of cellulose and proteins. In the present work, we aimed to stimulate Acanthamoeba castellanii excystment by treating their cysts with a cellulolytic enzyme, i.e., cellulase, or two proteolytic enzymes, i.e., collagenase and pepsin. While 11 days were necessary to obtain total excystment in the control at 27°C, only 48 h were sufficient at the same temperature to obtain 100% trophozoites in the presence of 25 U/mL cellulase, 50 U/mL collagenase or 100 U/mL pepsin. Additionally, more than 96% amoebae have excysted after only 24 h with 7.5 U/mL cellulase at 30°C. Nevertheless, no effect of the three enzymes was observed on the excystment of Balamuthia mandrillaris and Vermamoeba vermiformis. Surprisingly, A. castellanii trophozoites excysted in the presence of cellulase displayed a markedly shorter doubling time at 7 h, in comparison to the control at 23 h. Likewise, trophozoites doubled their population in 9 h when both cellulose and cellulase were added to the medium, indicating that Acanthamoeba cyst wall degradation products promote their trophozoite proliferation. The analysis of cysts in epifluorescent microscopy using FITC-lectins and in electron microscopy revealed a disorganized endocyst and a reduction of the intercystic space area after cellulase treatment, implying that these cellular events are preliminary to trophozoite release during excystment. Further studies would be necessary to determine the signaling pathways involved during this amoebal differentiation process to identify new therapeutic targets for the development of anti-acanthamoebal drugs.
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12
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A time-resolved multi-omics atlas of Acanthamoeba castellanii encystment. Nat Commun 2022; 13:4104. [PMID: 35835784 PMCID: PMC9283445 DOI: 10.1038/s41467-022-31832-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 06/30/2022] [Indexed: 12/14/2022] Open
Abstract
Encystment is a common stress response of most protists, including free-living amoebae. Cyst formation protects the amoebae from eradication and can increase virulence of the bacteria they harbor. Here, we mapped the global molecular changes that occur in the facultatively pathogenic amoeba Acanthamoeba castellanii during the early steps of the poorly understood process of encystment. By performing transcriptomic, proteomic, and phosphoproteomic experiments during encystment, we identified more than 150,000 previously undescribed transcripts and thousands of protein sequences absent from the reference genome. These results provide molecular details to the regulation of expected biological processes, such as cell proliferation shutdown, and reveal new insights such as a rapid phospho-regulation of sites involved in cytoskeleton remodeling and translation regulation. This work constitutes the first time-resolved molecular atlas of an encysting organism and a useful resource for further investigation of amoebae encystment to allow for a better control of pathogenic amoebae.
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13
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Boonhok R, Sangkanu S, Phumjan S, Jongboonjua R, Sangnopparat N, Kwankaew P, Tedasen A, Lim CL, Pereira MDL, Rahmatullah M, Wilairatana P, Wiart C, Dolma KG, Paul AK, Gupta M, Nissapatorn V. Curcumin effect on Acanthamoeba triangularis encystation under nutrient starvation. PeerJ 2022; 10:e13657. [PMID: 35811814 PMCID: PMC9261923 DOI: 10.7717/peerj.13657] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 06/09/2022] [Indexed: 01/17/2023] Open
Abstract
Background Curcumin is an active compound derived from turmeric, Curcuma longa, and is known for its benefits to human health. The amoebicidal activity of curcumin against Acanthamoeba triangularis was recently discovered. However, a physiological change of intracellular pathways related to A. triangularis encystation mechanism, including autophagy in the surviving amoeba after curcumin treatment, has never been reported. This study aims to investigate the effect of curcumin on the survival of A. triangularis under nutrient starvation and nutrient-rich condition, as well as to evaluate the A. triangularis encystation and a physiological change of Acanthamoeba autophagy at the mRNA level. Methods In this study, A. triangularis amoebas were treated with a sublethal dose of curcumin under nutrient starvation and nutrient-rich condition and the surviving amoebas was investigated. Cysts formation and vacuolization were examined by microscopy and transcriptional expression of autophagy-related genes and other encystation-related genes were evaluated by real-time PCR. Results A. triangularis cysts were formed under nutrient starvation. However, in the presence of the autophagy inhibitor, 3-methyladenine (3-MA), the percentage of cysts was significantly reduced. Interestingly, in the presence of curcumin, most of the parasites remained in the trophozoite stage in both the starvation and nutrient-rich condition. In vacuolization analysis, the percentage of amoebas with enlarged vacuole was increased upon starvation. However, the percentage was significantly declined in the presence of curcumin and 3-MA. Molecular analysis of A. triangularis autophagy-related (ATG) genes showed that the mRNA expression of the ATG genes, ATG3, ATG8b, ATG12, ATG16, under the starvation with curcumin was at a basal level along the treatment. The results were similar to those of the curcumin-treated amoebas under a nutrient-rich condition, except AcATG16 which increased later. On the other hand, mRNA expression of encystation-related genes, cellulose synthase and serine proteinase, remained unchanged during the first 18 h, but significantly increased at 24 h post treatment. Conclusion Curcumin inhibits cyst formation in surviving trophozoites, which may result from its effect on mRNA expression of key Acanthamoeba ATG-related genes. However, further investigation into the mechanism of curcumin in A. triangularis trophozoites arrest and its association with autophagy or other encystation-related pathways is needed to support the future use of curcumin.
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Affiliation(s)
- Rachasak Boonhok
- Department of Medical Technology, School of Allied Health Sciences, and Research Excellence Center for Innovation and Health Products (RECIHP), Walailak University, Thai Buri, Nakhon Si Thammarat, Thailand
| | - Suthinee Sangkanu
- School of Allied Health Sciences, Southeast Asia Water Team (SEA Water Team) and World Union for Herbal Drug Discovery (WUHeDD), and Research Excellence Center for Innovation and Health Products (RECIHP), Walailak University, Thai Buri, Nakhon Si Thammarat, Thailand
| | - Suganya Phumjan
- Department of Medical Technology, School of Allied Health Sciences, and Research Excellence Center for Innovation and Health Products (RECIHP), Walailak University, Thai Buri, Nakhon Si Thammarat, Thailand
| | - Ramita Jongboonjua
- Department of Medical Technology, School of Allied Health Sciences, and Research Excellence Center for Innovation and Health Products (RECIHP), Walailak University, Thai Buri, Nakhon Si Thammarat, Thailand
| | - Nawarat Sangnopparat
- Department of Medical Technology, School of Allied Health Sciences, and Research Excellence Center for Innovation and Health Products (RECIHP), Walailak University, Thai Buri, Nakhon Si Thammarat, Thailand
| | - Pattamaporn Kwankaew
- Department of Medical Technology, School of Allied Health Sciences, and Research Excellence Center for Innovation and Health Products (RECIHP), Walailak University, Thai Buri, Nakhon Si Thammarat, Thailand
| | - Aman Tedasen
- Department of Medical Technology, School of Allied Health Sciences, and Research Excellence Center for Innovation and Health Products (RECIHP), Walailak University, Thai Buri, Nakhon Si Thammarat, Thailand
| | - Chooi Ling Lim
- Division of Applied Biomedical Science and Biotechnology, School of Health Sciences, International Medical University, Kuala Lumpur, Malaysia
| | - Maria de Lourdes Pereira
- CICECO-Aveiro Institute of Materials and Department of Medical Sciences, University of Aveiro, Aveiro, Portugal
| | - Mohammed Rahmatullah
- Department of Biotechnology and Genetic Engineering, University of Development Alternative, Dhaka, Bangladesh
| | - Polrat Wilairatana
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Rachathewee, Bangkok, Thailand
| | - Christophe Wiart
- The Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
| | - Karma G. Dolma
- Department of Microbiology, Sikkim Manipal Institute of Medical Sciences, Sikkim, India
| | - Alok K. Paul
- School of Pharmacy and Pharmacology, University of Tasmania, Hobart, Tasmania, Australia
| | - Madhu Gupta
- Department of Pharmaceutics, Delhi Pharmaceutical Sciences and Research University, New Delhi, India
| | - Veeranoot Nissapatorn
- School of Allied Health Sciences, Southeast Asia Water Team (SEA Water Team) and World Union for Herbal Drug Discovery (WUHeDD), and Research Excellence Center for Innovation and Health Products (RECIHP), Walailak University, Thai Buri, Nakhon Si Thammarat, Thailand
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14
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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] [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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15
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Joo SY, Aung JM, Shin M, Moon EK, Kong HH, Goo YK, Chung DI, Hong Y. Sirtinol Supresses Trophozoites Proliferation and Encystation of Acanthamoeba via Inhibition of Sirtuin Family Protein. THE KOREAN JOURNAL OF PARASITOLOGY 2022; 60:1-6. [PMID: 35247948 PMCID: PMC8898648 DOI: 10.3347/kjp.2022.60.1.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 01/27/2022] [Indexed: 11/23/2022]
Abstract
The encystation of Acanthamoeba leads to the development of metabolically inactive and dormant cysts from vegetative trophozoites under unfavorable conditions. These cysts are highly resistant to anti-Acanthamoeba drugs and biocides. Therefore, the inhibition of encystation would be more effective in treating Acanthamoeba infection. In our previous study, a sirtuin family protein—Acanthamoeba silent-information regulator 2-like protein (AcSir2)—was identified, and its expression was discovered to be critical for Acanthamoeba castellanii proliferation and encystation. In this study, to develop Acanthamoeba sirtuin inhibitors, we examine the effects of sirtinol, a sirtuin inhibitor, on trophozoite growth and encystation. Sirtinol inhibited A. castellanii trophozoites proliferation (IC50=61.24 μM). The encystation rate of cells treated with sirtinol significantly decreased to 39.8% (200 μM sirtinol) after 24 hr of incubation compared to controls. In AcSir2-overexpressing cells, the transcriptional level of cyst-specific cysteine protease (CSCP), an Acanthamoeba cysteine protease involved in the encysting process, was 11.6- and 88.6-fold higher at 48 and 72 hr after induction of encystation compared to control. However, sirtinol suppresses CSCP transcription, resulting that the undegraded organelles and large molecules remained in sirtinol-treated cells during encystation. These results indicated that sirtinol sufficiently inhibited trophozoite proliferation and encystation, and can be used to treat Acanthamoeba infections.
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Affiliation(s)
- So-Young Joo
- Department of Parasitology and Tropical Medicine, School of Medicine, Kyungpook National University, Daegu 41944,
Korea
| | - Ja Moon Aung
- Department of Parasitology and Tropical Medicine, School of Medicine, Kyungpook National University, Daegu 41944,
Korea
| | - Minsang Shin
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu 41944,
Korea
| | - Eun-Kyung Moon
- Department of Medical Zoology, Kyung Hee University School of Medicine, Seoul 02447,
Korea
| | - Hyun-Hee Kong
- Department of Parasitology, Dong-A University College of Medicine, Busan 49201,
Korea
| | - Youn-Kyoung Goo
- Department of Parasitology and Tropical Medicine, School of Medicine, Kyungpook National University, Daegu 41944,
Korea
| | - Dong-Il Chung
- Department of Parasitology and Tropical Medicine, School of Medicine, Kyungpook National University, Daegu 41944,
Korea
| | - Yeonchul Hong
- Department of Parasitology and Tropical Medicine, School of Medicine, Kyungpook National University, Daegu 41944,
Korea
- Corresponding author ()
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16
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Boonhok R, Sangkanu S, Norouzi R, Siyadatpanah A, Mirzaei F, Mitsuwan W, Charong N, Wisessombat S, Pereira MDL, Rahmatullah M, Wilairatana P, Wiart C, Tabo HA, Dolma KG, Nissapatorn V. Amoebicidal activity of Cassia angustifolia extract and its effect on Acanthamoeba triangularis autophagy-related gene expression at the transcriptional level. Parasitology 2021; 148:1074-1082. [PMID: 33966667 PMCID: PMC11010062 DOI: 10.1017/s0031182021000718] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 04/07/2021] [Accepted: 04/29/2021] [Indexed: 12/30/2022]
Abstract
Cassia angustifolia Vahl. plant is used for many therapeutic purposes, for example, in people with constipation, skin diseases, including helminthic and parasitic infections. In our study, we demonstrated an amoebicidal activity of C. angustifolia extract against Acanthamoeba triangularis trophozoite at a micromolar level. Scanning electron microscopy (SEM) images displayed morphological changes in the Acanthamoeba trophozoite, which included the formation of pores in cell membrane and the membrane rupture. In addition to the amoebicidal activity, effects of the extract on surviving trophozoites were observed, which included cyst formation and vacuolization by a microscope and transcriptional expression of Acanthamoeba autophagy in response to the stress by quantitative polymerase chain reaction. Our data showed that the surviving trophozoites were not transformed into cysts and the trophozoite number with enlarged vacuole was not significantly different from that of untreated control. Molecular analysis data demonstrated that the mRNA expression of AcATG genes was slightly changed. Interestingly, AcATG16 decreased significantly at 12 h post treatment, which may indicate a transcriptional regulation by the extract or a balance of intracellular signalling pathways in response to the stress, whereas AcATG3 and AcATG8b remained unchanged. Altogether, these data reveal the anti-Acanthamoeba activity of C. angustifolia extract and the autophagic response in the surviving trophozoites under the plant extract pressure, along with data on the formation of cysts. These represent a promising plant for future drug development. However, further isolation and purification of an active compound and cytotoxicity against human cells are needed, including a study on the autophagic response at the protein level.
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Affiliation(s)
- Rachasak Boonhok
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat80160, Thailand
| | - Suthinee Sangkanu
- School of Allied Health Sciences, Southeast Asia Water Team (SEA Water Team) and World Union for Herbal Drug Discovery (WUHeDD), and Research Excellence Center for Innovation and Health Products, Walailak University, Nakhon Si Thammarat80160, Thailand
| | - Roghayeh Norouzi
- Department of Pathobiology, Faculty of Veterinary Medicine, University of Tabriz, Tabriz51664, Iran
| | - Abolghasem Siyadatpanah
- Ferdows School of Paramedical and Health, Birjand University of Medical Sciences, Birjand9717853577, Iran
| | - Farzaneh Mirzaei
- Department Parasitology and Mycology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd14188-15971, Iran
| | - Watcharapong Mitsuwan
- School of Allied Health Sciences, Southeast Asia Water Team (SEA Water Team) and World Union for Herbal Drug Discovery (WUHeDD), and Research Excellence Center for Innovation and Health Products, Walailak University, Nakhon Si Thammarat80160, Thailand
- Akkhraratchakumari Veterinary College, and Research Center of Excellence in Innovation of Essential Oil, Walailak University, Nakhon Si Thammarat80160, Thailand
| | - Nurdina Charong
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat80160, Thailand
| | - Sueptrakool Wisessombat
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat80160, Thailand
| | - Maria de Lourdes Pereira
- Department of Medical Sciences, CICECO-Aveiro Institute of Materials, University of Aveiro, Aveiro3810-193, Portugal
| | - Mohammed Rahmatullah
- Department of Biotechnology and Genetic Engineering, University of Development Alternative Lalmatia, Dhaka1209, Bangladesh
| | - Polrat Wilairatana
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok10400, Thailand
| | - Christophe Wiart
- School of Pharmacy, University of Nottingham Malaysia Campus, Selangor43500, Malaysia
| | - Hazel Anne Tabo
- Biological Sciences Department, College of Science and Computer Studies, De La Salle University-Dasmarinas, Cavite4115, Philippines
| | - Karma G. Dolma
- Department of Microbiology, Sikkim Manipal Institute of Medical Sciences (SMIMS), Gangtok, Sikkim737102, India
| | - Veeranoot Nissapatorn
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat80160, Thailand
- School of Allied Health Sciences, Southeast Asia Water Team (SEA Water Team) and World Union for Herbal Drug Discovery (WUHeDD), and Research Excellence Center for Innovation and Health Products, Walailak University, Nakhon Si Thammarat80160, Thailand
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17
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Boonhok R, Sangkanu S, Chuprom J, Srisuphanunt M, Norouzi R, Siyadatpanah A, Mirzaei F, Mitsuwan W, Wisessombat S, de Lourdes Pereira M, Rahmatullah M, Wilairatana P, Wiart C, Ling LC, Dolma KG, Nissapatorn V. Peganum harmala Extract Has Antiamoebic Activity to Acanthamoeba triangularis Trophozoites and Changes Expression of Autophagy-Related Genes. Pathogens 2021; 10:842. [PMID: 34357992 PMCID: PMC8308471 DOI: 10.3390/pathogens10070842] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 07/02/2021] [Accepted: 07/02/2021] [Indexed: 02/03/2023] Open
Abstract
Peganum harmala, a well-known medicinal plant, has been used for several therapeutic purposes as it contains numerous pharmacological active compounds. Our study reported an anti-parasitic activity of P. harmala seed extract against Acanthamoeba triangularis. The stress induced by the extract on the surviving trophozoites for Acanthamoeba encystation and vacuolization was examined by microscopy, and transcriptional expression of Acanthamoeba autophagy-related genes was investigated by quantitative PCR. Our results showed that the surviving trophozoites were not transformed into cysts, and the number of trophozoites with enlarged vacuoles were not significantly different from that of untreated control. Molecular analysis data demonstrated that the mRNA expression of tested AcATG genes, i.e., ATG3, ATG8b, and ATG16, was at a basal level along the treatment. However, upregulation of AcATG16 at 24 h post treatment was observed, which may indicate an autophagic activity of this protein in response to the stress. Altogether, these data revealed the anti-Acanthamoeba activity of P. harmala extract and indicated the association of autophagy mRNA expression and cyst formation under the extract stress, representing a promising plant for future drug development. However, further identification of an active compound and a study of autophagy at the protein level are needed.
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Affiliation(s)
- Rachasak Boonhok
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand; (R.B.); (M.S.); (S.W.)
| | - Suthinee Sangkanu
- Research Excellence Center for Innovation and Health Products (RECIHP), School of Allied Health Sciences, Southeast Asia Water Team (SEA Water Team) and World Union for Herbal Drug Discovery (WUHeDD), Walailak University, Nakhon Si Thammarat 80160, Thailand; (S.S.); (J.C.)
| | - Julalak Chuprom
- Research Excellence Center for Innovation and Health Products (RECIHP), School of Allied Health Sciences, Southeast Asia Water Team (SEA Water Team) and World Union for Herbal Drug Discovery (WUHeDD), Walailak University, Nakhon Si Thammarat 80160, Thailand; (S.S.); (J.C.)
| | - Mayuna Srisuphanunt
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand; (R.B.); (M.S.); (S.W.)
| | - Roghayeh Norouzi
- Department of Pathobiology, Faculty of Veterinary Medicine, University of Tabriz, Tabriz 5166616471, Iran;
| | - Abolghasem Siyadatpanah
- Ferdows School of Paramedical and Health, Birjand University of Medical Sciences, Birjand 9717853577, Iran;
| | - Farzaneh Mirzaei
- Department Parasitology and Mycology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd 14188-15971, Iran;
| | - Watcharapong Mitsuwan
- Akkhraratchakumari Veterinary College and Research Center of Excellence in Innovation of Essential Oil, Walailak University, Nakhon Si Thammarat 80160, Thailand;
| | - Sueptrakool Wisessombat
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand; (R.B.); (M.S.); (S.W.)
| | - Maria de Lourdes Pereira
- CICECO-Aveiro Institute of Materials and Department of Medical Sciences, University of Aveiro, 3810-193 Aveiro, Portugal;
| | - Mohammed Rahmatullah
- Department of Biotechnology and Genetic Engineering, University of Development Alternative, Lalmatia, Dhaka 1209, Bangladesh;
| | - Polrat Wilairatana
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Christophe Wiart
- School of Pharmacy, University of Nottingham Malaysia Campus, Selangor 43500, Malaysia;
| | - Lim Chooi Ling
- Division of Applied Biomedical Science and Biotechnology, School of Health Sciences, International Medical University, Kuala Lumpur 57000, Malaysia;
| | - Karma G. Dolma
- Department of Microbiology, Sikkim Manipal Institute of Medical Sciences (SMIMS), Sikkim 737102, India;
| | - Veeranoot Nissapatorn
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand; (R.B.); (M.S.); (S.W.)
- Research Excellence Center for Innovation and Health Products (RECIHP), School of Allied Health Sciences, Southeast Asia Water Team (SEA Water Team) and World Union for Herbal Drug Discovery (WUHeDD), Walailak University, Nakhon Si Thammarat 80160, Thailand; (S.S.); (J.C.)
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The Autophagy Machinery in Human-Parasitic Protists; Diverse Functions for Universally Conserved Proteins. Cells 2021; 10:cells10051258. [PMID: 34069694 PMCID: PMC8161075 DOI: 10.3390/cells10051258] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/17/2021] [Accepted: 05/18/2021] [Indexed: 12/31/2022] Open
Abstract
Autophagy is a eukaryotic cellular machinery that is able to degrade large intracellular components, including organelles, and plays a pivotal role in cellular homeostasis. Target materials are enclosed by a double membrane vesicle called autophagosome, whose formation is coordinated by autophagy-related proteins (ATGs). Studies of yeast and Metazoa have identified approximately 40 ATGs. Genome projects for unicellular eukaryotes revealed that some ATGs are conserved in all eukaryotic supergroups but others have arisen or were lost during evolution in some specific lineages. In spite of an apparent reduction in the ATG molecular machinery found in parasitic protists, it has become clear that ATGs play an important role in stage differentiation or organelle maintenance, sometimes with an original function that is unrelated to canonical degradative autophagy. In this review, we aim to briefly summarize the current state of knowledge in parasitic protists, in the light of the latest important findings from more canonical model organisms. Determining the roles of ATGs and the diversity of their functions in various lineages is an important challenge for understanding the evolutionary background of autophagy.
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Matsuoka T. Early signaling pathways mediating dormant cyst formation in terrestrial unicellular eukaryote Colpoda. FEMS Microbiol Lett 2021; 368:6156630. [PMID: 33677557 DOI: 10.1093/femsle/fnab019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 02/24/2021] [Indexed: 12/23/2022] Open
Abstract
Dormant (resting) cyst formation (encystment) in unicellular eukaryotes is the process of a large-scale digestion of vegetative cell structures and reconstruction into the dormant form, which is performed by cell signaling pathways accompanied by up- or down-regulation of protein expression, and by posttranslational modification such as phosphorylation. In this review, the author describes the morphogenetic events during encystment of Colpoda and the early molecular events in the Ca2+/calmodulin-triggered signaling pathways for encystment, based mainly on our research results of the past 10 years; especially, the author discusses the role of c-AMP dependently phosphorylated proteins (ribosomal P0 protein, ribosomal S5 protein, Rieske iron-sulfur protein, actin and histone H4) and encystment-dependently upregulated (EF-1α-HSP60, actin-related protein) and downregulated proteins (ATP synthase β-chain). In addition, the roles of AMPK, a key molecule in the signaling pathways leading to Colpoda encystment, and differentially expressed genes and proteins during encystment of other ciliates are discussed.
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Affiliation(s)
- Tatsuomi Matsuoka
- Department of Biological Science, Faculty of Science and Technology, Kochi University, Akebono-cho 2-5-1, Kochi, Japan
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20
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Joo SY, Aung JM, Shin M, Moon EK, Kong HH, Goo YK, Chung DI, Hong Y. The role of the Acanthamoeba castellanii Sir2-like protein in the growth and encystation of Acanthamoeba. Parasit Vectors 2020; 13:368. [PMID: 32698828 PMCID: PMC7376869 DOI: 10.1186/s13071-020-04237-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 07/15/2020] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND The encystation of Acanthamoeba leads to the development of resilient cysts from vegetative trophozoites. This process is essential for the survival of parasites under unfavorable conditions. Previous studies have reported that, during the encystation of A. castellanii, the expression levels of encystation-related factors are upregulated. However, the regulatory mechanisms for their expression during the encystation process remains unknown. Proteins in the sirtuin family, which consists of nicotinamide adenine dinucleotide-dependent deacetylases, are known to play an important role in various cellular functions. In the present study, we identified the Acanthamoeba silent-information regulator 2-like protein (AcSir2) and examined its role in the growth and encystation of Acanthamoeba. METHODS We obtained the full-length sequence for AcSir2 using reverse-transcription polymerase chain reaction. In Acanthamoeba transfectants that constitutively overexpress AcSir2 protein, SIRT deacetylase activity was measured, and the intracellular localization of AcSir2 and the effects on the growth and encystation of trophozoites were examined. In addition, the sirtuin inhibitor salermide was used to determine whether these effects were caused by AcSir2 overexpression RESULTS: AcSir2 was classified as a class-IV sirtuin. AcSir2 exhibited functional SIRT deacetylase activity, localized mainly in the nucleus, and its transcription was upregulated during encystation. In trophozoites, AcSir2 overexpression led to greater cell growth, and this growth was inhibited by treatment with salermide, a sirtuin inhibitor. When AcSir2 was overexpressed in the cysts, the encystation rate was significantly higher; this was also reversed with salermide treatment. In AcSir2-overexpressing encysting cells, the transcription of cellulose synthase was highly upregulated compared with that of control cells, and this upregulation was abolished with salermide treatment. Transmission electron microscope-based ultrastructural analysis of salermide-treated encysting cells showed that the structure of the exocyst wall and intercyst space was impaired and that the endocyst wall had not formed. CONCLUSIONS These results indicate that AcSir2 is a SIRT deacetylase that plays an essential role as a regulator of a variety of cellular processes and that the regulation of AcSir2 expression is important for the growth and encystation of A. castellanii.
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Affiliation(s)
- So-Young Joo
- Department of Parasitology and Tropical Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Ja Moon Aung
- Department of Parasitology and Tropical Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Minsang Shin
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Eun-Kyung Moon
- Department of Medical Zoology, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - Hyun-Hee Kong
- Department of Parasitology, Dong-A University College of Medicine, Busan, Republic of Korea
| | - Youn-Kyoung Goo
- Department of Parasitology and Tropical Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Dong-Il Chung
- Department of Parasitology and Tropical Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Yeonchul Hong
- Department of Parasitology and Tropical Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea.
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21
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Alkyl-carbon chain length of two distinct compounds and derivatives are key determinants of their anti-Acanthamoeba activities. Sci Rep 2020; 10:6420. [PMID: 32286337 PMCID: PMC7156471 DOI: 10.1038/s41598-020-62934-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 03/05/2020] [Indexed: 02/06/2023] Open
Abstract
The opportunistic pathogen, Acanthamoeba castellanii is the causative agent for the sight threatening infection Acanthamoeba keratitis (AK). It is commonly associated with contact lens wearers, and prevalence is increasing at an alarming rate due to an inadequate preventive strategy to protect the lens from this protist. This problem is compounded by the lack of an effective acanthamoebocide, particularly with cysticidal activity in the contact lens solutions. We have used cytotoxicity assays and a variety of biophysical approaches to show that two molecules with tails made of alkyl carbon, alkylphosphocholines (APCs) and quaternary ammonium compounds (QACs) had significant chain-length dependent efficacy against A. castellanii trophozoites, the latter producing death via permeabilization, and DNA complexing. QACs were more effective than APCs and had activity against cysts. Conversely, the QAC with 12 alkyl carbon chain, was non toxic, its presence increased A. castellanii trophozoites biomass and delayed encystation by 96 h. Interestingly, it was unable to induce excystation and increased trophozoite sensitivity to APC16. These results present a mono- and multi-inhibitor management strategy effective against trophozoites and cysts that may be useful for formulating into contact lense cleaning solutions and reducing AK incidence.
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22
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Zhang Z, Guo M, Li Y, Shen M, Kong D, Shao J, Ding H, Tan S, Chen A, Zhang F, Zheng S. RNA-binding protein ZFP36/TTP protects against ferroptosis by regulating autophagy signaling pathway in hepatic stellate cells. Autophagy 2019; 16:1482-1505. [PMID: 31679460 DOI: 10.1080/15548627.2019.1687985] [Citation(s) in RCA: 245] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Ferroptosis is a recently discovered form of programmed cell death, but its regulatory mechanisms remain poorly understood. Here, we show that the RNA-binding protein ZFP36/TTP (ZFP36 ring finger protein) plays a crucial role in regulating ferroptosis in hepatic stellate cells (HSCs). Upon exposure to ferroptosis-inducing compounds, the ubiquitin ligase FBXW7/CDC4 (F-box and WD repeat domain containing 7) decreased ZFP36 protein expression by recognizing SFSGLPS motif. FBXW7 plasmid contributed to classical ferroptotic events, whereas ZFP36 plasmid impaired FBXW7 plasmid-induced HSC ferroptosis. Interestingly, ZFP36 plasmid inhibited macroautophagy/autophagy activation by destabilizing ATG16L1 (autophagy related 16 like 1) mRNA. ATG16L1 plasmid eliminated the inhibitory action of ZFP36 plasmid on ferroptosis, and FBXW7 plasmid enhanced the effect of ATG16L1 plasmid on autophagy. Importantly, ZFP36 plasmid promoted ATG16L1 mRNA decay via binding to the AU-rich elements (AREs) within the 3'-untranslated region. The internal mutation of the ARE region abrogated the ZFP36-mediated ATG16L1 mRNA instability, and prevented ZFP36 plasmid-mediated ferroptosis resistance. In mice, treatment with erastin and sorafenib alleviated murine liver fibrosis by inducing HSC ferroptosis. HSC-specific overexpression of Zfp36 impaired erastin- or sorafenib-induced HSC ferroptosis. Noteworthy, we analyzed the effect of sorafenib on HSC ferroptosis in fibrotic patients with hepatocellular carcinoma receiving sorafenib monotherapy. Attractively, sorafenib monotherapy led to ZFP36 downregulation, ferritinophagy activation, and ferroptosis induction in human HSCs. Overall, these results revealed novel molecular mechanisms and signaling pathways of ferroptosis, and also identified ZFP36-autophagy-dependent ferroptosis as a potential target for the treatment of liver fibrosis. ABBREVIATIONS ARE: AU-rich elements; ATG: autophagy related; BECN1: beclin 1; CHX: cycloheximide; COL1A1: collagen type I alpha 1 chain; ELAVL1/HuR: ELAV like RNA binding protein 1; FBXW7/CDC4: F-box and WD repeat domain containing 7; FN1: fibronectin 1; FTH1: ferritin heavy chain 1; GPX4/PHGPx: glutathione peroxidase 4; GSH: glutathione; HCC: hepatocellular carcinoma; HSC: hepatic stellate cell; LSEC: liver sinusoidal endothelial cell; MAP1LC3A: microtubule associated protein 1 light chain 3 alpha; MDA: malondialdehyde; NCOA4: nuclear receptor coactivator 4; PTGS2/COX2: prostaglandin-endoperoxide synthase 2; RBP: RNA-binding protein; ROS: reactive oxygen species; SLC7A11/xCT: solute carrier family 7 member 11; SQSTM1/p62: sequestosome 1; TNF: tumor necrosis factor; TP53/p53: tumor protein p53; UTR: untranslated region; ZFP36/TTP: ZFP36 ring finger protein.
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Affiliation(s)
- Zili Zhang
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine , Nanjing, China
| | - Mei Guo
- Department of Pathogenic biology and Immunology, Medical School, Southeast University , Nanjing, China
| | - Yujia Li
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine , Nanjing, China
| | - Min Shen
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine , Nanjing, China
| | - Desong Kong
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine , Nanjing, China
| | - Jiangjuan Shao
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine , Nanjing, China
| | - Hai Ding
- Department of Integrated TCM and Western Medicine, Nanjing Hospital Affiliated to Nanjing University of Chinese Medicine , Nanjing, China
| | - Shanzhong Tan
- Department of Integrated TCM and Western Medicine, Nanjing Hospital Affiliated to Nanjing University of Chinese Medicine , Nanjing, China
| | - Anping Chen
- Department of Pathology, School of Medicine, Saint Louis University , St Louis, USA
| | - Feng Zhang
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine , Nanjing, China.,Jiangsu Key Laboratory of Therapeutic Material of Chinese Medicine, Nanjing University of Chinese Medicine , Nanjing, China
| | - Shizhong Zheng
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine , Nanjing, China.,Jiangsu Key Laboratory of Therapeutic Material of Chinese Medicine, Nanjing University of Chinese Medicine , Nanjing, China
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23
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Samba-Louaka A, Delafont V, Rodier MH, Cateau E, Héchard Y. Free-living amoebae and squatters in the wild: ecological and molecular features. FEMS Microbiol Rev 2019; 43:415-434. [DOI: 10.1093/femsre/fuz011] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 04/30/2019] [Indexed: 02/06/2023] Open
Abstract
ABSTRACT
Free-living amoebae are protists frequently found in water and soils. They feed on other microorganisms, mainly bacteria, and digest them through phagocytosis. It is accepted that these amoebae play an important role in the microbial ecology of these environments. There is a renewed interest for the free-living amoebae since the discovery of pathogenic bacteria that can resist phagocytosis and of giant viruses, underlying that amoebae might play a role in the evolution of other microorganisms, including several human pathogens. Recent advances, using molecular methods, allow to bring together new information about free-living amoebae. This review aims to provide a comprehensive overview of the newly gathered insights into (1) the free-living amoeba diversity, assessed with molecular tools, (2) the gene functions described to decipher the biology of the amoebae and (3) their interactions with other microorganisms in the environment.
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Affiliation(s)
- Ascel Samba-Louaka
- Laboratoire Ecologie et Biologie des Interactions (EBI), Equipe Microbiologie de l'Eau, Université de Poitiers, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 POITIERS Cedex 9, France
| | - Vincent Delafont
- Laboratoire Ecologie et Biologie des Interactions (EBI), Equipe Microbiologie de l'Eau, Université de Poitiers, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 POITIERS Cedex 9, France
| | - Marie-Hélène Rodier
- Laboratoire Ecologie et Biologie des Interactions (EBI), Equipe Microbiologie de l'Eau, Université de Poitiers, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 POITIERS Cedex 9, France
- Laboratoire de Parasitologie et Mycologie, CHU La Milétrie, 2 rue de la Milétrie, 86021 Poitiers Cedex, France
| | - Estelle Cateau
- Laboratoire Ecologie et Biologie des Interactions (EBI), Equipe Microbiologie de l'Eau, Université de Poitiers, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 POITIERS Cedex 9, France
- Laboratoire de Parasitologie et Mycologie, CHU La Milétrie, 2 rue de la Milétrie, 86021 Poitiers Cedex, France
| | - Yann Héchard
- Laboratoire Ecologie et Biologie des Interactions (EBI), Equipe Microbiologie de l'Eau, Université de Poitiers, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 POITIERS Cedex 9, France
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24
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Chan LL, Mak JW, Ambu S, Chong PY. Identification and ultrastructural characterization of Acanthamoeba bacterial endocytobionts belonging to the Alphaproteobacteria class. PLoS One 2018; 13:e0204732. [PMID: 30356282 PMCID: PMC6200196 DOI: 10.1371/journal.pone.0204732] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 09/13/2018] [Indexed: 12/17/2022] Open
Abstract
The detection and identification of two endocytobiotic bacterial strains, one affiliated to the “Candidatus Caedibacter acanthamoebae”/“Ca. Paracaedimonas acanthamoeba”, and another to the endosymbiont of Acanthamoeba UWC8 and “Ca. Jidaibacter acanthamoeba” are described. For endocytobiont screening, we developed a PCR method with a set of broad-range bacterial 16S rRNA primers to substitute the commonly used but technically demanding fluorescent in situ hybridization technique. Our PCR test alone without sequencing failed to discriminate the endocytobiont-containing and endocytobiont-free Acanthamoeba sp. due to the presence of mismatched primers to host mitochondrial DNA. We highlighted the need to perform bacterial primer checking against the Acanthamoeba genome to avoid false positive detection in PCR. Although the genetic aspect of “Ca. Caedibacter acanthamoebae”/“Ca. Paracaedimonas acanthamoeba” and the endosymbiont of Acanthamoeba UWC8/“Ca. Jidaibacter acanthamoeba” are well studied, knowledge pertaining to their morphologies are quite vague. Hence, we used transmission electron microscopy to examine our endocytobionts which are affiliated to previously described intracellular bacteria of Acanthamoeba sp. We used good-quality TEM images for the localization and the fate of the current endocytobionts inside different life stages of the hosts. Furthermore, to the best of our knowledge, our TEM findings are the first to provide morphological evidence for the clearance of defective Acanthamoeba endocytobionts via an autophagic-like process.
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Affiliation(s)
- Li Li Chan
- Pathology Division, School of Medicine, International Medical University, Kuala Lumpur, Malaysia
- * E-mail:
| | - Joon Wah Mak
- Pathology Division, School of Medicine, International Medical University, Kuala Lumpur, Malaysia
- School of Postgraduate Studies and Research, International Medical University, Kuala Lumpur, Malaysia
| | - Stephen Ambu
- Pathology Division, School of Medicine, International Medical University, Kuala Lumpur, Malaysia
- School of Postgraduate Studies and Research, International Medical University, Kuala Lumpur, Malaysia
| | - Pei Yee Chong
- Medical Sciences, School of Medicine, International Medical University, Kuala Lumpur, Malaysia
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25
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Schaap P, Schilde C. Encystation: the most prevalent and underinvestigated differentiation pathway of eukaryotes. MICROBIOLOGY-SGM 2018; 164:727-739. [PMID: 29620506 DOI: 10.1099/mic.0.000653] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Not long ago, protists were considered one of four eukaryote kingdoms, but recent gene-based phylogenies show that they contribute to all nine eukaryote subdomains. The former kingdoms of animals, plants and fungi are now relegated to lower ranks within subdomains. Most unicellular protists respond to adverse conditions by differentiating into dormant walled cysts. As cysts, they survive long periods of starvation, drought and other environmental threats, only to re-emerge when conditions improve. For protists pathogens, the resilience of their cysts can prevent successful treatment or eradication of the disease. In this context, effort has been directed towards understanding the molecular mechanisms that control encystation. We here firstly summarize the prevalence of encystation across protists and next focus on Amoebozoa, where most of the health-related issues occur. We review current data on processes and genes involved in encystation of the obligate parasite Entamoeba histolytica and the opportunistic pathogen Acanthamoeba. We show how the cAMP-mediated signalling pathway that controls spore and stalk cell encapsulation in Dictyostelium fruiting bodies could be retraced to a stress-induced pathway controlling encystation in solitary Amoebozoa. We highlight the conservation and prevalence of cAMP signalling genes in Amoebozoan genomes and the suprisingly large and varied repertoire of proteins for sensing and processing environmental signals in individual species.
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Affiliation(s)
- Pauline Schaap
- School of Life Sciences, University of Dundee, Dundee DD15EH, UK
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26
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Moon EK, Lee S, Quan FS, Kong HH. Chloroquine as a possible disinfection adjunct of disinfection solutions against Acanthamoeba. Exp Parasitol 2018; 188:102-106. [PMID: 29625097 DOI: 10.1016/j.exppara.2018.04.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 03/14/2018] [Accepted: 04/02/2018] [Indexed: 12/13/2022]
Abstract
Acanthamoeba keratitis is commonly encountered by contact lens wearers. Contact lens solution plays an important role in the safe use of contact lenses. The most popular products for disinfecting lenses are multipurpose disinfecting solutions (MPDS). However, almost all MPDS retailed in Korea are ineffective in killing Acanthamoeba. The objective of this study was to determine the possibility of using autophagy inhibitor chloroquine as a disinfecting agent to improve the amoebicidal activity of MPDS against Acanthamoeba, especially the cyst. Amoebicidal effects of eight different MPDSs combined with chloroquine (CQ), an autophagy inhibitor, and their cytotoxicities to human corneal epithelium cells were determined. Almost all MPDS showed strong amoebicidal effect on trophozoites after 8 h of exposure. However, they showed inadequate amoebicidal effect on cysts even after 24 h of exposure. MPDSs combined with 100 μM CQ increased their amoebicidal effects on immature cyst by inhibiting formation of mature cysts. Incubation with 100 μM CQ for 30 min did not have cytotoxicity to human corneal epithelial cells.
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Affiliation(s)
- Eun-Kyung Moon
- Department of Medical Zoology, Kyung Hee University School of Medicine, Seoul 02447, Republic of Korea
| | - Seungeun Lee
- Department of Parasitology, Dong-A University College of Medicine, Busan 49201, Republic of Korea
| | - Fu-Shi Quan
- Department of Medical Zoology, Kyung Hee University School of Medicine, Seoul 02447, Republic of Korea
| | - Hyun-Hee Kong
- Department of Parasitology, Dong-A University College of Medicine, Busan 49201, Republic of Korea.
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27
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Moon EK, Hong Y, Lee HA, Quan FS, Kong HH. DNA Methylation of Gene Expression in Acanthamoeba castellanii Encystation. THE KOREAN JOURNAL OF PARASITOLOGY 2017; 55:115-120. [PMID: 28506032 PMCID: PMC5450953 DOI: 10.3347/kjp.2017.55.2.115] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 03/13/2017] [Accepted: 04/03/2017] [Indexed: 12/04/2022]
Abstract
Encystation mediating cyst specific cysteine proteinase (CSCP) of Acanthamoeba castellanii is expressed remarkably during encystation. However, the molecular mechanism involved in the regulation of CSCP gene expression remains unclear. In this study, we focused on epigenetic regulation of gene expression during encystation of Acanthamoeba. To evaluate methylation as a potential mechanism involved in the regulation of CSCP expression, we first investigated the correlation between promoter methylation status of CSCP gene and its expression. A 2,878 bp of promoter sequence of CSCP gene was amplified by PCR. Three CpG islands (island 1–3) were detected in this sequence using bioinformatics tools. Methylation of CpG island in trophozoites and cysts was measured by bisulfite sequence PCR. CSCP promoter methylation of CpG island 1 (1,633 bp) was found in 8.2% of trophozoites and 7.3% of cysts. Methylation of CpG island 2 (625 bp) was observed in 4.2% of trophozoites and 5.8% of cysts. Methylation of CpG island 3 (367 bp) in trophozoites and cysts was both 3.6%. These results suggest that DNA methylation system is present in CSCP gene expression of Acanthamoeba. In addition, the expression of encystation mediating CSCP is correlated with promoter CpG island 1 hypomethylation.
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Affiliation(s)
- Eun-Kyung Moon
- Department of Medical Zoology, Kyung Hee University School of Medicine, Seoul 02447, Korea
| | - Yeonchul Hong
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 41944, Korea
| | - Hae-Ahm Lee
- Department of Pharmacology, Kyungpook National University School of Medicine, Daegu 41944, Korea
| | - Fu-Shi Quan
- Department of Medical Zoology, Kyung Hee University School of Medicine, Seoul 02447, Korea
| | - Hyun-Hee Kong
- Department of Parasitology, Dong-A University College of Medicine, Busan 49201, Korea
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Identification of Atg8 from Acanthamoeba castellanii by genetic complementation in Saccharomyces cerevisiae. Mol Biochem Parasitol 2016; 210:55-57. [PMID: 27585717 DOI: 10.1016/j.molbiopara.2016.08.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 08/20/2016] [Accepted: 08/26/2016] [Indexed: 12/19/2022]
Abstract
Autophagy is a eukaryotic process responsible for the degradation of intracellular content such as damaged organelles. Several putative autophagy-related genes have been identified within the annotated genome of the free-living amoeba Acanthamoeba castellanii. However, the involvement of the corresponding proteins in the autophagy pathway had not been formerly established. Here, we report that AcAtg8 cDNA can complement ATG8-deficient Saccharomyces cerevisiae.
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Moon EK, Hong Y, Chung DI, Goo YK, Kong HH. Identification of Protein Arginine Methyltransferase 5 as a Regulator for Encystation of Acanthamoeba. THE KOREAN JOURNAL OF PARASITOLOGY 2016; 54:133-8. [PMID: 27180570 PMCID: PMC4870982 DOI: 10.3347/kjp.2016.54.2.133] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 12/10/2015] [Accepted: 12/29/2015] [Indexed: 11/23/2022]
Abstract
Encystation is an essential process for Acanthamoeba survival under nutrient-limiting conditions and exposure to drugs. The expression of several genes has been observed to increase or decrease during encystation. Epigenetic processes involved in regulation of gene expression have been shown to play a role in several pathogenic parasites. In the present study, we identified the protein arginine methyltransferase 5 (PRMT5), a known epigenetic regulator, in Acanthamoeba castellanii. PRMT5 of A. castellanii (AcPRMT5) contained domains found in S-adenosylmethionine-dependent methyltransferases and in PRMT5 arginine-N-methyltransferase. Expression levels of AcPRMT5 were increased during encystation of A. castellanii. The EGFP-PRMT5 fusion protein was mainly localized in the nucleus of trophozoites. A. castellanii transfected with siRNA designed against AcPRMT5 failed to form mature cysts. The findings of this study lead to a better understanding of epigenetic mechanisms behind the regulation of encystation in cyst-forming pathogenic protozoa.
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Affiliation(s)
- Eun-Kyung Moon
- Department of Medical Zoology, Kyung Hee University School of Medicine, Seoul 02447, Korea
| | - Yeonchul Hong
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 41944, Korea
| | - Dong-Il Chung
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 41944, Korea
| | - Youn-Kyoung Goo
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 41944, Korea
| | - Hyun-Hee Kong
- Department of Parasitology, Dong-A University College of Medicine, Busan 49201, Korea
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Kim SH, Moon EK, Hong Y, Chung DI, Kong HH. Autophagy protein 12 plays an essential role in Acanthamoeba encystation. Exp Parasitol 2015; 159:46-52. [DOI: 10.1016/j.exppara.2015.08.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 06/25/2015] [Accepted: 08/16/2015] [Indexed: 11/28/2022]
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Potential Value of Cellulose Synthesis Inhibitors Combined With PHMB in the Treatment of Acanthamoeba Keratitis. Cornea 2015; 34:1593-8. [DOI: 10.1097/ico.0000000000000642] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Autophagy inhibitors as a potential antiamoebic treatment for Acanthamoeba keratitis. Antimicrob Agents Chemother 2015; 59:4020-5. [PMID: 25896709 DOI: 10.1128/aac.05165-14] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 04/16/2015] [Indexed: 02/06/2023] Open
Abstract
Acanthamoeba cysts are resistant to extreme physical and chemical conditions. Autophagy is an essential pathway for encystation of Acanthamoeba cells. To evaluate the possibility of an autophagic Acanthamoeba encystation mechanism, we evaluated autophagy inhibitors, such as 3-methyladenine (3MA), LY294002, wortmannin, bafilomycin A, and chloroquine. Among these autophagy inhibitors, the use of 3MA and chloroquine showed a significant reduction in the encystation ratio in Acanthamoeba cells. Wortmannin also inhibited the formation of mature cysts, while LY294002 and bafilomycin A did not affect the encystation of Acanthamoeba cells. Transmission electron microscopy revealed that 3MA and wortmannin inhibited autophagy formation and that chloroquine interfered with the formation of autolysosomes. Inhibition of autophagy or autolysosome formation resulted in a significant block in the encystation in Acanthamoeba cells. Clinical treatment with 0.02% polyhexamethylene biguanide (PHMB) showed high cytopathic effects on Acanthamoeba trophozoites and cysts; however, it also revealed high cytopathic effects on human corneal epithelial cells. In this study, we investigated effects of the combination of a low (0.00125%) concentration of PHMB with each of the autophagy inhibitors 3MA, wortmannin, and chloroquine on Acanthamoeba and human corneal epithelial cells. These new combination treatments showed low cytopathic effects on human corneal cells and high cytopathic effects on Acanthamoeba cells. Taken together, these results provide fundamental information for optimizing the treatment of Acanthamoeba keratitis.
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Abedkhojasteh H, Niyyati M, Rezaei S, Mohebali M, Farnia S, Kazemi-Rad E, Roozafzoon R, Sianati H, Rezaeian M, Heidari M. Identifying differentially expressed genes in trophozoites and cysts of Acanthamoeba T4 genotype: Implications for developing new treatments for Acanthamoeba keratitis. Eur J Protistol 2015; 51:34-41. [DOI: 10.1016/j.ejop.2014.10.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 10/02/2014] [Accepted: 10/04/2014] [Indexed: 12/23/2022]
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Chloroquine has a cytotoxic effect on Acanthamoeba encystation through modulation of autophagy. Antimicrob Agents Chemother 2014; 58:6235-41. [PMID: 25114131 DOI: 10.1128/aac.03164-14] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Encystation of Acanthamoeba castellanii is associated with resistance to chemotherapeutic agents. Blocking the encystation process could potentiate the efficacy of chemotherapeutic agents and biocides. During encystation, autophagy is highly stimulated and required for proper encystation of Acanthamoeba. In this study, the cytotoxic effect of chloroquine, a well-known autophagy-inhibitory drug, was tested in A. castellanii. Chloroquine was able to selectively reduce cell survival during the encystation of A. castellanii. However, A. castellanii trophozoites and mature cysts were resistant to chloroquine. Chloroquine treatment led to an increase in the number and size of lysosomes in encysting cells. Moreover, chloroquine inhibited the degradation of long-lived proteins in the encysting cells. Decreased autophagic flux, indicated by an increased number of lysosomes and decreased degradation of long-lived proteins, may be the mechanism by which cell death is induced by chloroquine in encysting Acanthamoeba. These results suggest a potential novel therapeutic application of chloroquine as an anti-Acanthamoeba drug. Our findings also suggest that targeting autophagy could be a therapeutic strategy against Acanthamoeba infection.
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Moon EK, Hong Y, Chung DI, Goo YK, Kong HH. Down-regulation of cellulose synthase inhibits the formation of endocysts in Acanthamoeba. THE KOREAN JOURNAL OF PARASITOLOGY 2014; 52:131-5. [PMID: 24850955 PMCID: PMC4028449 DOI: 10.3347/kjp.2014.52.2.131] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 03/03/2014] [Accepted: 03/03/2014] [Indexed: 11/23/2022]
Abstract
Acanthamoeba cysts are resistant to unfavorable physiological conditions and various disinfectants. Acanthamoeba cysts have 2 walls containing various sugar moieties, and in particular, one third of the inner wall is composed of cellulose. In this study, it has been shown that down-regulation of cellulose synthase by small interfering RNA (siRNA) significantly inhibits the formation of mature Acanthamoeba castellanii cysts. Calcofluor white staining and transmission electron microscopy revealed that siRNA transfected amoeba failed to form an inner wall during encystation and thus are likely to be more vulnerable. In addition, the expression of xylose isomerase, which is involved in cyst wall formation, was not altered in cellulose synthase down-regulated amoeba, indicating that cellulose synthase is a crucial factor for inner wall formation by Acanthamoeba during encystation.
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Affiliation(s)
- Eun-Kyung Moon
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 700-422, Korea
| | - Yeonchul Hong
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 700-422, Korea
| | - Dong-Il Chung
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 700-422, Korea
| | - Youn-Kyoung Goo
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 700-422, Korea
| | - Hyun-Hee Kong
- Department of Parasitology, Dong-A University College of Medicine, Busan 602-714, Korea
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Moon EK, Hong Y, Chung DI, Kong HH. Identification of atg8 isoform in encysting Acanthamoeba. THE KOREAN JOURNAL OF PARASITOLOGY 2013; 51:497-502. [PMID: 24327773 PMCID: PMC3857495 DOI: 10.3347/kjp.2013.51.5.497] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 08/23/2013] [Accepted: 08/29/2013] [Indexed: 12/31/2022]
Abstract
Autophagy-related protein 8 (Atg8) is an essential component of autophagy formation and encystment of cyst-forming parasites, and some protozoa, such as, Acanthamoeba, Entamoeba, and Dictyostelium, have been reported to possess a type of Atg8. In this study, an isoform of Atg8 was identified and characterized in Acanthamoeba castellanii (AcAtg8b). AcAtg8b protein was found to encode 132 amino acids and to be longer than AcAtg8 protein, which encoded 117 amino acids. Real-time PCR analysis showed high expression levels of AcAtg8b and AcAtg8 during encystation. Fluorescence microscopy demonstrated that AcAtg8b is involved in the formation of the autophagosomal membrane. Chemically synthesized siRNA against AcAtg8b reduced the encystation efficiency of Acanthamoeba, confirming that AcAtg8b, like AcAtg8, is an essential component of cyst formation in Acanthamoeba. Our findings suggest that Acanthamoeba has doubled the number of Atg8 gene copies to ensure the successful encystation for survival when 1 copy is lost. These 2 types of Atg8 identified in Acanthamoeba provide important information regarding autophagy formation, encystation mechanism, and survival of primitive, cyst-forming protozoan parasites.
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Affiliation(s)
- Eun-Kyung Moon
- Department of Parasitology, Kyungpook National University School of Medicine, Daegu 700-422, Korea
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Cysteine protease inhibitor (AcStefin) is required for complete cyst formation of Acanthamoeba. EUKARYOTIC CELL 2013; 12:567-74. [PMID: 23397569 DOI: 10.1128/ec.00308-12] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The encystation of Acanthamoeba leads to the formation of resilient cysts from vegetative trophozoites. This process is essential for parasite survival under unfavorable conditions, such as those associated with starvation, low temperatures, and biocides. Furthermore, cysteine proteases have been implicated in the massive turnover of intracellular components required for encystation. Thus, strict modulation of the activities of cysteine proteases is required to protect Acanthamoeba from intracellular damage. However, mechanisms underlying the control of protease activity during encystation have not been established in Acanthamoeba. In the present study, we identified and characterized Acanthamoeba cysteine protease inhibitor (AcStefin), which was found to be highly expressed during encystation and to be associated with lysosomes by fluorescence microscopy. Recombinant AcStefin inhibited various cysteine proteases, including human cathepsin B, human cathepsin L, and papain. Transfection with small interfering RNA against AcStefin increased cysteine protease activity during encystation and resulted in incomplete cyst formation, reduced excystation efficiency, and a significant reduction in cytoplasmic area. Taken together, these results indicate that AcStefin is involved in the modulation of cysteine proteases and that it plays an essential role during the encystation of Acanthamoeba.
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Moon EK, Chung DI, Hong Y, Kong HH. Protein kinase C signaling molecules regulate encystation of Acanthamoeba. Exp Parasitol 2012; 132:524-9. [DOI: 10.1016/j.exppara.2012.07.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Revised: 07/16/2012] [Accepted: 07/23/2012] [Indexed: 01/09/2023]
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Moon EK, Hong Y, Chung DI, Kong HH. Cysteine protease involving in autophagosomal degradation of mitochondria during encystation of Acanthamoeba. Mol Biochem Parasitol 2012; 185:121-6. [DOI: 10.1016/j.molbiopara.2012.07.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 07/24/2012] [Accepted: 07/30/2012] [Indexed: 10/28/2022]
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