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Sharma C, Khurana S, Bhatia A, Arora A, Gupta A. The gene expression and proteomic profiling of Acanthamoeba isolates. Exp Parasitol 2023; 255:108630. [PMID: 37820893 DOI: 10.1016/j.exppara.2023.108630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 09/27/2023] [Accepted: 10/08/2023] [Indexed: 10/13/2023]
Abstract
INTRODUCTION The free-living protozoan Acanthamoeba can cause severe keratitis known as Acanthamoeba Keratitis (AK) and granulomatous amoebic encephalitis (GAE). The pathogenesis of Acanthamoeba includes intricate interactions between the organism and the host's immune system. The downstream analysis of a well-annotated genome assembly along with proteomic analysis can unravel several biological processes and aid in the identification of potential genes involved in pathogenicity. METHODS Based on the next-generation sequencing data analysis, genes including lysophospholipase, phospholipase, S8/S53 peptidase, carboxylesterase, and mannose-binding protein were selected as probable pathogenic targets that were validated by conventional PCR in a total of 30 Acanthamoeba isolates. This was followed by real-time PCR for the evaluation of relative gene expression in the keratitis and amoebic encephalitis animal model induced using keratitis (CHA5), encephalitis (CHA24) and non-pathogenic environmental isolate (CHA36). In addition, liquid chromatography-mass spectrometry (LC-MS/MS) was performed for keratitis, encephalitis, and non-pathogenic environmental isolate before and after treatment with polyhexamethylene biguanide (PHMB). RESULTS The conventional PCR demonstrated the successful amplification of lysophospholipase, phospholipase, S8/S53 peptidase, carboxylesterase, and mannose-binding protein genes in clinical and environmental isolates. The expression analysis revealed phospholipase, lysophospholipase, and mannose-binding genes to be significantly upregulated in the keratitis isolate (CHA 5) during AK in the animal model. In the case of the amoebic encephalitis model, phospholipase, lysophospholipase, S8/S53 peptidase, and carboxylesterase were significantly upregulated in the encephalitis isolate compared to the keratitis isolate. The proteomic data revealed differential protein expression in pathogenic versus non-pathogenic isolates in the pre and post-treatment with PHMB. CONCLUSION The gene expression data suggests that lysophospholipase, phospholipase, S8/S53 peptidase, carboxylesterase, and mannose-binding protein (MBP) could play a role in the contact-dependent and independent mechanisms of Acanthamoeba pathogenesis. In addition, the proteomic profiling of the 3 isolates revealed differential protein expression crucial for parasite growth, survival, and virulence. Our results provide baseline data for selecting possible pathogenic targets that could be utilized for designing knockout experiments in the future.
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Affiliation(s)
- Chayan Sharma
- Department of Medical Parasitology, Postgraduate Institute of Medical Education & Research, Chandigarh, 160012, India.
| | - Sumeeta Khurana
- Department of Medical Parasitology, Postgraduate Institute of Medical Education & Research, Chandigarh, 160012, India.
| | - Alka Bhatia
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education & Research, Chandigarh, 160012, India.
| | - Amit Arora
- Department of Medical Microbiology, Postgraduate Institute of Medical Education & Research, Chandigarh, 160012, India.
| | - Amit Gupta
- Advanced Eye Centre, Postgraduate Institute of Medical Education & Research, Chandigarh, 160012, India.
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2
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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: 22] [Impact Index Per Article: 11.0] [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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3
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Corsaro D. Acanthamoeba Mannose and Laminin Binding Proteins Variation across Species and Genotypes. Microorganisms 2022; 10:2162. [PMID: 36363753 PMCID: PMC9692275 DOI: 10.3390/microorganisms10112162] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 10/26/2022] [Indexed: 11/26/2023] Open
Abstract
Acanthamoeba is a ubiquitous free-living amoeba capable of being an opportunistic pathogen in humans and animals. A critical step in infection is the adhesion of the amoeba to host cells and tissues, and two major parasite adhesins, mannose-binding protein (MBP) and laminin-binding protein (LBP), are known to recognize the cell surface glycoproteins and those of the extracellular matrix, respectively. In this study, the available genomes of Acanthamoeba were analysed to recover the sequences of MBP and LBP using previously published genetic data. Genes for both proteins were successfully obtained from strains belonging to various genotypes (T4A, T4D, T4G, T4F, T2, T5, T10, T22, T7 and T18), resulting in a single gene for LBP but identifying two types of MBP, MBP1 and MBP2. Phylogenetic analysis based on deduced amino acid sequences shows that both MBP and LBP have a branching pattern that is consistent with that based on 18S rDNA, indicating that changes in both proteins occurred during diversification of Acanthamoeba lines. Notably, all MBPs possess a conserved motif, shared with some bacterial C-type lectins, which could be the recognition site for mannose binding.
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Henriquez FL, Mooney R, Bandel T, Giammarini E, Zeroual M, Fiori PL, Margarita V, Rappelli P, Dessì D. Paradigms of Protist/Bacteria Symbioses Affecting Human Health: Acanthamoeba species and Trichomonas vaginalis. Front Microbiol 2021; 11:616213. [PMID: 33488560 PMCID: PMC7817646 DOI: 10.3389/fmicb.2020.616213] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 12/07/2020] [Indexed: 12/15/2022] Open
Abstract
Ever since the publication of the seminal paper by Lynn Margulis in 1967 proposing the theory of the endosymbiotic origin of organelles, the study of the symbiotic relationships between unicellular eukaryotes and prokaryotes has received ever-growing attention by microbiologists and evolutionists alike. While the evolutionary significance of the endosymbiotic associations within protists has emerged and is intensively studied, the impact of these relationships on human health has been seldom taken into account. Microbial endosymbioses involving human eukaryotic pathogens are not common, and the sexually transmitted obligate parasite Trichomonas vaginalis and the free-living opportunistic pathogen Acanthamoeba represent two unique cases in this regard, to date. The reasons of this peculiarity for T. vaginalis and Acanthamoeba may be due to their lifestyles, characterized by bacteria-rich environments. However, this characteristic does not fully explain the reason why no bacterial endosymbiont has yet been detected in unicellular eukaryotic human pathogens other than in T. vaginalis and Acanthamoeba, albeit sparse and poorly investigated examples of morphological identification of bacteria-like microorganisms associated with Giardia and Entamoeba were reported in the past. In this review article we will present the body of experimental evidences revealing the profound effects of these examples of protist/bacteria symbiosis on the pathogenesis of the microbial species involved, and ultimately their impact on human health.
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Affiliation(s)
- Fiona L Henriquez
- School of Health and Life Sciences, University of West Scotland, Paisley, United Kingdom
| | - Ronnie Mooney
- School of Health and Life Sciences, University of West Scotland, Paisley, United Kingdom
| | - Timothy Bandel
- School of Health and Life Sciences, University of West Scotland, Paisley, United Kingdom
| | - Elisa Giammarini
- School of Health and Life Sciences, University of West Scotland, Paisley, United Kingdom
| | - Mohammed Zeroual
- School of Health and Life Sciences, University of West Scotland, Paisley, United Kingdom.,Dipartimento di Scienze Biomediche, Università degli Studi di Sassari, Sassari, Italy
| | - Pier Luigi Fiori
- Dipartimento di Scienze Biomediche, Università degli Studi di Sassari, Sassari, Italy.,Mediterrenean Center for Disease Control, Sassari, Italy
| | - Valentina Margarita
- Dipartimento di Scienze Biomediche, Università degli Studi di Sassari, Sassari, Italy
| | - Paola Rappelli
- Dipartimento di Scienze Biomediche, Università degli Studi di Sassari, Sassari, Italy.,Mediterrenean Center for Disease Control, Sassari, Italy
| | - Daniele Dessì
- Dipartimento di Scienze Biomediche, Università degli Studi di Sassari, Sassari, Italy.,Mediterrenean Center for Disease Control, Sassari, Italy
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5
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Carvalho-Silva AC, Coelho CH, Cirelli C, Crepaldi F, Rodrigues-Chagas IA, Furst C, Pimenta DC, Toledo JSD, Fernandes AP, Costa AO. Differential expression of Acanthamoeba castellanii proteins during amoebic keratitis in rats. Exp Parasitol 2020; 221:108060. [PMID: 33338467 DOI: 10.1016/j.exppara.2020.108060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 11/04/2020] [Accepted: 12/13/2020] [Indexed: 11/25/2022]
Abstract
Amoebic keratitis (AK) is a sight-threatening infection characterized by a severe inflammation of the cornea, caused by the free-living protozoan of the genus Acanthamoeba. Identification of amoebic proteins involved in AK pathogenesis may help to elucidate molecular mechanisms of infection and contribute to indicate diagnostic and therapeutic targets. In this study, we evaluated changes in the expression profile of Acanthamoeba proteins triggered by the invasive process, using an approach involving two-dimensional polyacrylamide gel electrophoresis (2DE PAGE), followed by mass spectrometry identification (ESI-IT-TOF LC-MSn). AK was induced by intrastromal inoculation in Wistar rats, using trophozoites from a T4 genotype, human case-derived A. castellanii strain under prolonged axenic culture. Cultures re-isolated from the lesions after two successive passages in the animals were used as biological triplicate for proteomic experiments. Analysis of the protein profile comparing long-term and re-isolated cultures indicated 62 significant spots, from which 27 proteins could be identified in the Acanthamoeba proteome database. Five of them (Serpin, Carboxypeptidase A1, Hypothetical protein, Calponin domain-containing protein, aldo/keto reductase) were exclusively found in the re-isolated trophozoites. Our analysis also revealed that a concerted modulation of several biochemical pathways is triggered when A. castellanii switches from a free-living style to a parasitic mode, including energetic metabolism, proteolytic activity, control of gene expression, protein degradation and methylation of DNA, which may be also involved in gain of virulence in an animal model of AK.
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Affiliation(s)
- Ana Carolina Carvalho-Silva
- Department of Clinical and Toxicological Analysis, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Camila H Coelho
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Cecília Cirelli
- Department of Clinical and Toxicological Analysis, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Frederico Crepaldi
- Department of Clinical and Toxicological Analysis, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | | | - Cinthia Furst
- Department of Pathology, Health Sciences Center, Federal University of Espírito Santo, Vitória, ES, Brazil
| | | | - Juliano Simões de Toledo
- Department of Clinical and Toxicological Analysis, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Ana Paula Fernandes
- Department of Clinical and Toxicological Analysis, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Adriana Oliveira Costa
- Department of Clinical and Toxicological Analysis, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
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Angelici MC, Walochnik J, Calderaro A, Saxinger L, Dacks JB. Free-living amoebae and other neglected protistan pathogens: Health emergency signals? Eur J Protistol 2020; 77:125760. [PMID: 33340850 DOI: 10.1016/j.ejop.2020.125760] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 10/25/2020] [Accepted: 11/13/2020] [Indexed: 02/08/2023]
Abstract
Protistan parasites have an undisputed global health impact. However, outside of a few key exceptions, e.g. the agent of malaria, most of these infectious agents are neglected as important health threats. The Symposium entitled "Free-living amoebae and neglected pathogenic protozoa: health emergency signals?" held at the European Congress of Protistology in Rome, July 2019, brought together researchers addressing scientific and clinical questions about some of these fascinating organisms. Topics presented included the molecular basis of pathogenicity in Acanthamoeba; genomics of Naegleria fowleri; and epidemiology of poorly diagnosed enteric protistan species, including Giardia, Cryptosporidium, Blastocystis, Dientamoeba. The Symposium aim was to excite the audience about the opportunities and challenges of research in these underexplored organisms and to underline the public health implications of currently under-appreciated protistan infections. The major take home message is that any knowledge that we gain about these organisms will allow us to better address them, in terms of monitoring and treatment, as sources of future health emergencies.
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Affiliation(s)
| | - Julia Walochnik
- Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Adriana Calderaro
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Lynora Saxinger
- Division of Infectious Diseases, Department of Medicine, University of Alberta, Alberta, Canada
| | - Joel B Dacks
- Division of Infectious Diseases, Department of Medicine, University of Alberta, Alberta, Canada; Institute of Parasitology, Biology Centre, Czech Academy of Sciences České Budějovice, Czech Republic.
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7
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Betanzos A, Bañuelos C, Orozco E. Host Invasion by Pathogenic Amoebae: Epithelial Disruption by Parasite Proteins. Genes (Basel) 2019; 10:E618. [PMID: 31416298 PMCID: PMC6723116 DOI: 10.3390/genes10080618] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 04/25/2019] [Accepted: 04/29/2019] [Indexed: 02/07/2023] Open
Abstract
The epithelium represents the first and most extensive line of defence against pathogens, toxins and pollutant agents in humans. In general, pathogens have developed strategies to overcome this barrier and use it as an entrance to the organism. Entamoeba histolytica, Naegleriafowleri and Acanthamoeba spp. are amoebae mainly responsible for intestinal dysentery, meningoencephalitis and keratitis, respectively. These amoebae cause significant morbidity and mortality rates. Thus, the identification, characterization and validation of molecules participating in host-parasite interactions can provide attractive targets to timely intervene disease progress. In this work, we present a compendium of the parasite adhesins, lectins, proteases, hydrolases, kinases, and others, that participate in key pathogenic events. Special focus is made for the analysis of assorted molecules and mechanisms involved in the interaction of the parasites with epithelial surface receptors, changes in epithelial junctional markers, implications on the barrier function, among others. This review allows the assessment of initial host-pathogen interaction, to correlate it to the potential of parasite invasion.
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Affiliation(s)
- Abigail Betanzos
- Consejo Nacional de Ciencia y Tecnología (CONACYT), Mexico City 03940, Mexico
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico City 07360, Mexico
| | - Cecilia Bañuelos
- Coordinación General de Programas de Posgrado Multidisciplinarios, Programa de Doctorado Transdisciplinario en Desarrollo Científico y Tecnológico para la Sociedad, CINVESTAV-IPN, Mexico City 07360, Mexico
| | - Esther Orozco
- Departamento de Infectómica y Patogénesis Molecular, CINVESTAV-IPN, Mexico City 07360, Mexico.
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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: 6.3] [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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Łanocha-Arendarczyk N, Baranowska-Bosiacka I, Gutowska I, Kot K, Metryka E, Kosik-Bogacka DI. Relationship between antioxidant defense in Acanthamoeba spp. infected lungs and host immunological status. Exp Parasitol 2018; 193:58-65. [PMID: 30201450 DOI: 10.1016/j.exppara.2018.09.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 08/02/2018] [Accepted: 09/04/2018] [Indexed: 01/26/2023]
Abstract
The role of oxidative stress in the pathogenicity of acanthamoebiasis is an important aspect of the intricate and complex host-parasite relationship. The aim of this experimental study was to determine oxidative stress through the assessment of lipid peroxidation product (LPO) levels and antioxidant defense mechanism in Acanthamoeba spp. lung infections in immunocompetent and immunosuppressed hosts. In Acanthamoeba spp. infected immunocompetent mice we noted a significant increase in lung lipid peroxidation products (LPO) at 8 days and 16 days post infection (dpi). There was a significant upregulation in lung LPO in immunocompetent and immunosuppressed mice infected by Acanthamoeba spp. at 16 dpi. The superoxide dismutase activity decreased significantly in lungs in immunosuppressed mice at 8 dpi. The catalase activity was significantly upregulated in lungs in immunocompetent vs. immunosuppressed group and in immunocompetent vs. control mice at 16 dpi. The glutathione reductase activity was significantly lower in immunosuppressed group vs. immunosuppressed control at 24 dpi. We found significant glutathione peroxidase downregulation in immunocompetent and immunosuppressed groups vs. controls at 8 dpi, and in immunosuppressed vs. immunosuppressed control at 16 dpi. The consequence of the inflammatory response in immunocompetent and immunosuppressed hosts in the course of experimental Acanthamoeba spp. infection was the reduction of the antioxidant capacity of the lungs resulting from changes in the activity of antioxidant enzymes. Therefore, the imbalance between oxidant and antioxidant processes may play a major role in pathology associated with Acanthamoeba pneumonia.
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Affiliation(s)
- N Łanocha-Arendarczyk
- Department of Biology and Medical Parasitology, Pomeranian Medical University in Szczecin, Poland
| | - I Baranowska-Bosiacka
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University in Szczecin, Poland
| | - I Gutowska
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, Poland
| | - K Kot
- Department of Biology and Medical Parasitology, Pomeranian Medical University in Szczecin, Poland
| | - E Metryka
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University in Szczecin, Poland
| | - D I Kosik-Bogacka
- Department of Biology and Medical Parasitology, Pomeranian Medical University in Szczecin, Poland.
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Ng SL, Nordin A, Abd Ghafar N, Suboh Y, Ab Rahim N, Chua KH. Acanthamoeba-mediated cytopathic effect correlates with MBP and AhLBP mRNA expression. Parasit Vectors 2017; 10:625. [PMID: 29282148 PMCID: PMC5745754 DOI: 10.1186/s13071-017-2547-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 11/21/2017] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND In recent years, the concern of Acanthamoeba keratitis has increased since the infection is often associated with contact lens use. Partial 18S rRNA genotypic identification of Acanthamoeba isolates is important to correlate with pathophysiological properties in order to evaluate the degree of virulence. This is the first report of genotypic identification for clinical isolates of Acanthamoeba from corneal scrapings of keratitis in Malaysia. This study is also the first to correlate the mRNA expression of MBP and AhLBP as virulent markers for axenic strains of Acanthamoeba. RESULTS In this study, ten clinical isolates were obtained from corneal scrapings. Rns genotype and intra-genotypic variation at the DF3 region of the isolates were identified. Results revealed that all clinical isolates belonged to the T4 genotype, with T4/6 (4 isolates), T4/2 (3 isolates), T4/16 (2 isolates) and one new genotype T4 sequence (T4/36), being determined. The axenic clinical isolates were cytopathogenic to rabbit corneal fibroblasts. MBP and AhLBP mRNA expression are directly correlated to Acanthamoeba cytopathic effect. CONCLUSIONS All ten Malaysian clinical isolates were identified as genotype T4 which is predominantly associated with AK. Measuring the mRNA expression of Acanthamoeba virulent markers could be useful in the understanding of the pathogenesis of Acanthamoeba keratitis.
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Affiliation(s)
- Sook-Luan Ng
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latif, 56000, Kuala Lumpur, Bandar Tun Razak, Malaysia
| | - Anisah Nordin
- Department of Parasitology and Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latif, 56000, Kuala Lumpur, Bandar Tun Razak, Malaysia
| | - Norzana Abd Ghafar
- Department of Anatomy, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latif, 56000, Kuala Lumpur, Bandar Tun Razak, Malaysia
| | - Yusof Suboh
- Department of Parasitology and Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latif, 56000, Kuala Lumpur, Bandar Tun Razak, Malaysia
| | - Noraina Ab Rahim
- Department of Parasitology and Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latif, 56000, Kuala Lumpur, Bandar Tun Razak, Malaysia
| | - Kien-Hui Chua
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latif, 56000, Kuala Lumpur, Bandar Tun Razak, Malaysia.
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11
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Lorenzo-Morales J, Khan NA, Walochnik J. An update on Acanthamoeba keratitis: diagnosis, pathogenesis and treatment. ACTA ACUST UNITED AC 2015; 22:10. [PMID: 25687209 PMCID: PMC4330640 DOI: 10.1051/parasite/2015010] [Citation(s) in RCA: 477] [Impact Index Per Article: 47.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 02/06/2015] [Indexed: 12/21/2022]
Abstract
Free-living amoebae of the genus Acanthamoeba are causal agents of a severe sight-threatening infection of the cornea known as Acanthamoeba keratitis. Moreover, the number of reported cases worldwide is increasing year after year, mostly in contact lens wearers, although cases have also been reported in non-contact lens wearers. Interestingly, Acanthamoeba keratitis has remained significant, despite our advances in antimicrobial chemotherapy and supportive care. In part, this is due to an incomplete understanding of the pathogenesis and pathophysiology of the disease, diagnostic delays and problems associated with chemotherapeutic interventions. In view of the devastating nature of this disease, here we present our current understanding of Acanthamoeba keratitis and molecular mechanisms associated with the disease, as well as virulence traits of Acanthamoeba that may be potential targets for improved diagnosis, therapeutic interventions and/or for the development of preventative measures. Novel molecular approaches such as proteomics, RNAi and a consensus in the diagnostic approaches for a suspected case of Acanthamoeba keratitis are proposed and reviewed based on data which have been compiled after years of working on this amoebic organism using many different techniques and listening to many experts in this field at conferences, workshops and international meetings. Altogether, this review may serve as the milestone for developing an effective solution for the prevention, control and treatment of Acanthamoeba infections.
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Affiliation(s)
- Jacob Lorenzo-Morales
- University Institute of Tropical Diseases and Public Health of the Canary Islands, University of La Laguna, Avda. Astrofísico Fco. Sánchez, S/N, 38203 La Laguna, Tenerife, Canary Islands, Spain
| | - Naveed A Khan
- Department of Biological and Biomedical Sciences, Aga Khan University, Karachi, Pakistan
| | - Julia Walochnik
- Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
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12
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DiGiacomo V, Meruelo D. Looking into laminin receptor: critical discussion regarding the non-integrin 37/67-kDa laminin receptor/RPSA protein. Biol Rev Camb Philos Soc 2015; 91:288-310. [PMID: 25630983 DOI: 10.1111/brv.12170] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 12/04/2014] [Accepted: 12/08/2014] [Indexed: 02/06/2023]
Abstract
The 37/67-kDa laminin receptor (LAMR/RPSA) was originally identified as a 67-kDa binding protein for laminin, an extracellular matrix glycoprotein that provides cellular adhesion to the basement membrane. LAMR has evolutionary origins, however, as a 37-kDa RPS2 family ribosomal component. Expressed in all domains of life, RPS2 proteins have been shown to have remarkably diverse physiological roles that vary across species. Contributing to laminin binding, ribosome biogenesis, cytoskeletal organization, and nuclear functions, this protein governs critical cellular processes including growth, survival, migration, protein synthesis, development, and differentiation. Unsurprisingly given its purview, LAMR has been associated with metastatic cancer, neurodegenerative disease and developmental abnormalities. Functioning in a receptor capacity, this protein also confers susceptibility to bacterial and viral infection. LAMR is clearly a molecule of consequence in human disease, directly mediating pathological events that make it a prime target for therapeutic interventions. Despite decades of research, there are still a large number of open questions regarding the cellular biology of LAMR, the nature of its ability to bind laminin, the function of its intrinsically disordered C-terminal region and its conversion from 37 to 67 kDa. This review attempts to convey an in-depth description of the complexity surrounding this multifaceted protein across functional, structural and pathological aspects.
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Affiliation(s)
- Vincent DiGiacomo
- Department of Pathology, New York University School of Medicine, 180 Varick Street, New York, NY 10014, U.S.A
| | - Daniel Meruelo
- Department of Pathology, New York University School of Medicine, 180 Varick Street, New York, NY 10014, U.S.A.,NYU Cancer Institute, 550 First Avenue, New York, NY 10016, U.S.A.,NYU Gene Therapy Center, 550 First Avenue, New York, NY 10016, U.S.A
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13
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Iqbal J, Naeem K, Siddiqui R, Khan NA. In vitro inhibition of protease-activated receptors 1, 2 and 4 demonstrates that these receptors are not involved in an Acanthamoeba castellanii keratitis isolate-mediated disruption of the human brain microvascular endothelial cells. Exp Parasitol 2014; 145 Suppl:S78-83. [DOI: 10.1016/j.exppara.2014.03.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 03/19/2014] [Accepted: 03/23/2014] [Indexed: 11/25/2022]
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14
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Tripathi T, Alizadeh H. Role of protease-activated receptors 2 (PAR2) in ocular infections and inflammation. ACTA ACUST UNITED AC 2014; 1. [PMID: 26078987 DOI: 10.14800/rci.291] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Protease-activated receptors (PARs) belong to a unique family of G protein-coupled receptors (GPCRs) that are cleaved at an activation site within the N-terminal exodomain by a variety of proteinases, essentially of the serine (Ser) proteinase family. After cleavage, the new N-terminal sequence functions as a tethered ligand, which binds intramolecularly to activate the receptor and initiate signaling. Cell signals induced through the activation of PARs appear to play a significant role in innate and adoptive immune responses of the cornea, which is constantly exposed to proteinases under physiological or pathophysiological conditions. Activation of PARs interferes with all aspects of the corneal physiology such as barrier function, transports, innate and adoptive immune responses, and functions of corneal nerves. It is not known whether the proteinase released from the microorganism can activate PARs and triggers the inflammatory responses. The role of PAR2 expressed by the corneal epithelial cells and activation by serine protease released from microorganism is discussed here. Recent evidences suggest that activation of PAR2, by the serine proteinases, play an important role in innate and inflammatory responses of the corneal infection.
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Affiliation(s)
- Trivendra Tripathi
- Department of Cell Biology and Immunology, University of North Texas Health Science Center, and North Texas Eye Research Institute, Fort Worth, Texas, 76107, USA
| | - Hassan Alizadeh
- Department of Cell Biology and Immunology, University of North Texas Health Science Center, and North Texas Eye Research Institute, Fort Worth, Texas, 76107, USA
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15
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Proteases from Entamoeba spp. and Pathogenic Free-Living Amoebae as Virulence Factors. J Trop Med 2013; 2013:890603. [PMID: 23476670 PMCID: PMC3582061 DOI: 10.1155/2013/890603] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 11/28/2012] [Indexed: 02/01/2023] Open
Abstract
The standard reference for pathogenic and nonpathogenic amoebae is the human parasite Entamoeba histolytica; a direct correlation between virulence and protease expression has been demonstrated for this amoeba. Traditionally, proteases are considered virulence factors, including those that produce cytopathic effects in the host or that have been implicated in manipulating the immune response. Here, we expand the scope to other amoebae, including less-pathogenic Entamoeba species and highly pathogenic free-living amoebae. In this paper, proteases that affect mucin, extracellular matrix, immune system components, and diverse tissues and cells are included, based on studies in amoebic cultures and animal models. We also include proteases used by amoebae to degrade iron-containing proteins because iron scavenger capacity is currently considered a virulence factor for pathogens. In addition, proteases that have a role in adhesion and encystation, which are essential for establishing and transmitting infection, are discussed. The study of proteases and their specific inhibitors is relevant to the search for new therapeutic targets and to increase the power of drugs used to treat the diseases caused by these complex microorganisms.
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Clarke M, Lohan AJ, Liu B, Lagkouvardos I, Roy S, Zafar N, Bertelli C, Schilde C, Kianianmomeni A, Bürglin TR, Frech C, Turcotte B, Kopec KO, Synnott JM, Choo C, Paponov I, Finkler A, Heng Tan CS, Hutchins AP, Weinmeier T, Rattei T, Chu JSC, Gimenez G, Irimia M, Rigden DJ, Fitzpatrick DA, Lorenzo-Morales J, Bateman A, Chiu CH, Tang P, Hegemann P, Fromm H, Raoult D, Greub G, Miranda-Saavedra D, Chen N, Nash P, Ginger ML, Horn M, Schaap P, Caler L, Loftus BJ. Genome of Acanthamoeba castellanii highlights extensive lateral gene transfer and early evolution of tyrosine kinase signaling. Genome Biol 2013; 14:R11. [PMID: 23375108 PMCID: PMC4053784 DOI: 10.1186/gb-2013-14-2-r11] [Citation(s) in RCA: 237] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 02/01/2013] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The Amoebozoa constitute one of the primary divisions of eukaryotes, encompassing taxa of both biomedical and evolutionary importance, yet its genomic diversity remains largely unsampled. Here we present an analysis of a whole genome assembly of Acanthamoeba castellanii (Ac) the first representative from a solitary free-living amoebozoan. RESULTS Ac encodes 15,455 compact intron-rich genes, a significant number of which are predicted to have arisen through inter-kingdom lateral gene transfer (LGT). A majority of the LGT candidates have undergone a substantial degree of intronization and Ac appears to have incorporated them into established transcriptional programs. Ac manifests a complex signaling and cell communication repertoire, including a complete tyrosine kinase signaling toolkit and a comparable diversity of predicted extracellular receptors to that found in the facultatively multicellular dictyostelids. An important environmental host of a diverse range of bacteria and viruses, Ac utilizes a diverse repertoire of predicted pattern recognition receptors, many with predicted orthologous functions in the innate immune systems of higher organisms. CONCLUSIONS Our analysis highlights the important role of LGT in the biology of Ac and in the diversification of microbial eukaryotes. The early evolution of a key signaling facility implicated in the evolution of metazoan multicellularity strongly argues for its emergence early in the Unikont lineage. Overall, the availability of an Ac genome should aid in deciphering the biology of the Amoebozoa and facilitate functional genomic studies in this important model organism and environmental host.
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Host-parasite interaction: parasite-derived and -induced proteases that degrade human extracellular matrix. J Parasitol Res 2012; 2012:748206. [PMID: 22792442 PMCID: PMC3390111 DOI: 10.1155/2012/748206] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Accepted: 05/07/2012] [Indexed: 12/29/2022] Open
Abstract
Parasitic protozoa are among the most important pathogens worldwide. Diseases such as malaria, leishmaniasis, amoebiasis, giardiasis, trichomoniasis, and trypanosomiasis affect millions of people. Humans are constantly threatened by infections caused by these pathogens. Parasites engage a plethora of surface and secreted molecules to attach to and enter mammalian cells. The secretion of lytic enzymes by parasites into host organs mediates critical interactions because of the invasion and destruction of interstitial tissues, enabling parasite migration to other sites within the hosts. Extracellular matrix is a complex, cross-linked structure that holds cells together in an organized assembly and that forms the basement membrane lining (basal lamina). The extracellular matrix represents a major barrier to parasites. Therefore, the evolution of mechanisms for connective-tissue degradation may be of great importance for parasite survival. Recent advances have been achieved in our understanding of the biochemistry and molecular biology of proteases from parasitic protozoa. The focus of this paper is to discuss the role of protozoan parasitic proteases in the degradation of host ECM proteins and the participation of these molecules as virulence factors. We divide the paper into two sections, extracellular and intracellular protozoa.
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Singh B, Fleury C, Jalalvand F, Riesbeck K. Human pathogens utilize host extracellular matrix proteins laminin and collagen for adhesion and invasion of the host. FEMS Microbiol Rev 2012; 36:1122-80. [PMID: 22537156 DOI: 10.1111/j.1574-6976.2012.00340.x] [Citation(s) in RCA: 213] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Revised: 02/08/2012] [Accepted: 03/29/2012] [Indexed: 01/11/2023] Open
Abstract
Laminin (Ln) and collagen are multifunctional glycoproteins that play an important role in cellular morphogenesis, cell signalling, tissue repair and cell migration. These proteins are ubiquitously present in tissues as a part of the basement membrane (BM), constitute a protective layer around blood capillaries and are included in the extracellular matrix (ECM). As a component of BMs, both Lns and collagen(s), thus function as major mechanical containment molecules that protect tissues from pathogens. Invasive pathogens breach the basal lamina and degrade ECM proteins of interstitial spaces and connective tissues using various ECM-degrading proteases or surface-bound plasminogen and matrix metalloproteinases recruited from the host. Most pathogens associated with the respiratory, gastrointestinal, or urogenital tracts, as well as with the central nervous system or the skin, have the capacity to bind and degrade Lns and collagen(s) in order to adhere to and invade host tissues. In this review, we focus on the adaptability of various pathogens to utilize these ECM proteins as enhancers for adhesion to host tissues or as a targets for degradation in order to breach the cellular barriers. The major pathogens discussed are Streptococcus, Staphylococcus, Pseudomonas, Salmonella, Yersinia, Treponema, Mycobacterium, Clostridium, Listeria, Porphyromonas and Haemophilus; Candida, Aspergillus, Pneumocystis, Cryptococcus and Coccidioides; Acanthamoeba, Trypanosoma and Trichomonas; retrovirus and papilloma virus.
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Affiliation(s)
- Birendra Singh
- Medical Microbiology, Department of Laboratory Medicine Malmö, Skåne University Hospital, Lund University, Malmö, Sweden
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19
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Siddiqui R, Khan NA. Biology and pathogenesis of Acanthamoeba. Parasit Vectors 2012; 5:6. [PMID: 22229971 PMCID: PMC3284432 DOI: 10.1186/1756-3305-5-6] [Citation(s) in RCA: 368] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 01/10/2012] [Indexed: 12/18/2022] Open
Abstract
Acanthamoeba is a free-living protist pathogen, capable of causing a blinding keratitis and fatal granulomatous encephalitis. The factors that contribute to Acanthamoeba infections include parasite biology, genetic diversity, environmental spread and host susceptibility, and are highlighted together with potential therapeutic and preventative measures. The use of Acanthamoeba in the study of cellular differentiation mechanisms, motility and phagocytosis, bacterial pathogenesis and evolutionary processes makes it an attractive model organism. There is a significant emphasis on Acanthamoeba as a Trojan horse of other microbes including viral, bacterial, protists and yeast pathogens.
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Rocha-Azevedo BD, Jamerson M, Cabral GA, Marciano-Cabral F. Acanthamoeba culbertsoni: Analysis of amoebic adhesion and invasion on extracellular matrix components collagen I and laminin-1. Exp Parasitol 2010; 126:79-84. [DOI: 10.1016/j.exppara.2009.08.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Revised: 08/12/2009] [Accepted: 08/14/2009] [Indexed: 11/28/2022]
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21
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Elsheikha HM, Khan NA. Protozoa traversal of the blood–brain barrier to invade the central nervous system. FEMS Microbiol Rev 2010; 34:532-53. [DOI: 10.1111/j.1574-6976.2010.00215.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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22
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Xuan YH, Hong YC, Lee YS, Kang SW, Yu HS, Ahn TI, Chung DI, Kong HH. Acanthamoeba healyi: expressed gene profiles with enhanced virulence after mouse-brain passage. Exp Parasitol 2009; 123:226-30. [PMID: 19651124 DOI: 10.1016/j.exppara.2009.07.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Revised: 12/26/2008] [Accepted: 07/21/2009] [Indexed: 10/20/2022]
Abstract
The virulence of Acanthamoeba can be attenuated by long-term in vitro cultivation, and can be recovered by serial mouse-brain passage via intranasal inoculation. Recovery is concomitant with changes in expression of virulence-related genes. To investigate the virulence factors of Acanthamoeba, expressed sequence tags (ESTs) from two kinds of cDNA libraries-long-term in vitro cultivated A. healyi (OLD) and three times mouse-brain passaged A. healyi (MBP)-were compared using reciprocal BLAST analysis, eukaryotic orthologous groups (KOG) assignment, and gene annotation. A total of 938 (OLD) and 1033 (MBP) ESTs were sequenced and resulted in the assembling of 718 OLD and 833 MBP unique sequences. Comparison of the KOG analysis revealed a relatively higher percentage of MBP ESTs in genes related to transcription (K group), amino acid transport and metabolism (E group), coenzyme transport and metabolism (H group), and secondary metabolites biosynthesis, transport and metabolism (Q group). However, a higher percentage of unidentified MBP ESTs (57.9%) than OLD ESTs (28.9%) was evidence of the limited understanding of virulence-related factors of Acanthamoeba. Characterization of the genes expressed during brain passage in mice will be useful in clarifying the pathogenesis of granulomatous amoebic encephalitis by Acanthamoeba.
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Affiliation(s)
- Ying-Hua Xuan
- Department of Parasitology, Kyungpook National University, School of Medicine, Taegu 700-422, Republic of Korea
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ROCHA-AZEVEDO BRUNODA, JAMERSON MELISSA, CABRAL GUYA, SILVA-FILHO FERNANDOC, MARCIANO-CABRAL FRANCINE. AcanthamoebaInteraction with Extracellular Matrix Glycoproteins: Biological and Biochemical Characterization and Role in Cytotoxicity and Invasiveness. J Eukaryot Microbiol 2009; 56:270-8. [DOI: 10.1111/j.1550-7408.2009.00399.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Kim WT, Kong HH, Ha YR, Hong YC, Jeong HJ, Yu HS, Chung DI. Comparison of specific activity and cytopathic effects of purified 33 kDa serine proteinase from Acanthamoeba strains with different degree of virulence. THE KOREAN JOURNAL OF PARASITOLOGY 2007; 44:321-30. [PMID: 17170574 PMCID: PMC2559134 DOI: 10.3347/kjp.2006.44.4.321] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The pathogenic mechanism of granulomatous amebic encephalitis (GAE) and amebic keratitis (AK) by Acanthamoeba has yet to be clarified. Protease has been recognized to play an important role in the pathogenesis of GAE and AK. In the present study, we have compared specific activity and cytopathic effects (CPE) of purified 33 kDa serine proteinases from Acanthamoeba strains with different degree of virulence (A. healyi OC-3A, A. lugdunensis KA/E2, and A. castellanii Neff). Trophozoites of the 3 strains revealed different degrees of CPE on human corneal epithelial (HCE) cells. The effect was remarkably reduced by adding phenylmethylsulfonylfluoride (PMSF), a serine proteinase inhibitor. This result indicated that PMSF-susceptible proteinase is the main component causing cytopathy to HCE cells by Acanthamoeba. The purified 33 kDa serine proteinase showed strong activity toward HCE cells and extracellular matrix proteins. The purified proteinase from OC-3A, the most virulent strain, demonstrated the highest enzyme activity compared to KA/E2, an ocular isolate, and Neff, a soil isolate. Polyclonal antibodies against the purified 33 kDa serine proteinase inhibit almost completely the proteolytic activity of culture supernatant of Acanthamoeba. In line with these results, the 33 kDa serine proteinase is suggested to play an important role in pathogenesis and to be the main component of virulence factor of Acanthamoeba.
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Affiliation(s)
- Won-Tae Kim
- Department of Parasitology, Kyungpook National University School of Medicine, Daegu, Korea
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Abstract
Acanthamoeba is an opportunistic protozoan that is widely distributed in the environment and is well recognized to produce serious human infections, including a blinding keratitis and a fatal encephalitis. This review presents our current understanding of the burden of Acanthamoeba infections on human health, their pathogenesis and pathophysiology, and molecular mechanisms associated with the disease, as well as virulence traits of Acanthamoeba that may be targets for therapeutic interventions and/or the development of preventative measures.
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Affiliation(s)
- Naveed Ahmed Khan
- School of Biological and Chemical Sciences, Birkbeck College, University of London, London, UK.
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Baldo ET, Moon EK, Kong HH, Chung DI. Acanthamoeba healyi: Molecular cloning and characterization of a coronin homologue, an actin-related protein. Exp Parasitol 2005; 110:114-22. [PMID: 15888293 DOI: 10.1016/j.exppara.2005.02.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2004] [Revised: 02/04/2005] [Accepted: 02/05/2005] [Indexed: 11/24/2022]
Abstract
Coronin, described in organisms from yeasts to humans, has been found to be involved in various actin-associated activities. It has yet to be described in Acanthamoeba, medically significant as the causative agent of granulomatous amebic encephalitis and amoebic keratitis and used extensively in actin-related studies. We isolated and characterized a cDNA encoding a coronin-like protein in A. healyi by sequence analysis and demonstrated intracellular localization of the gene product by transient transfection. Named Ahcoronin, the gene is composed of 454 amino acids which contain the characteristic WD repeats of coronin and coronin-like proteins. The C-terminal region of the gene was also predicted to have a high tendency of forming a coiled-coil, another structural characteristic of coronin. The gene showed a 50% homology to coronins. Ahcoronin occurs as a single copy and expressed as a transcript of approximately 1.4kb in A. healyi. Results of transfection showed that Ahcoronin was localized in the cell's periphery and in the leading edge consistent to that of actin. The fusion protein has also been observed to localize around phagocytic cups but was disassembled later during phagocytosis. Sequence analysis of Ahcoronin homologue of A. healyi showed numerous potential for further studies and is sure to contribute in the growing interest toward the properties and functions of coronin and coronin-like proteins.
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Affiliation(s)
- Eleonor T Baldo
- Department of Parasitology, Kyungpook National University School of Medicine, 101 Dongin-dong, Joong-gu, Taegu 700-422, Republic of Korea
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