1
|
Krishnan D, Pandey M, Nayak S, Ghosh SK. Novel Insights into the Wattle and Daub Model of Entamoeba Cyst Wall Formation and the Importance of Actin Cytoskeleton. Pathogens 2023; 13:20. [PMID: 38251328 PMCID: PMC10818507 DOI: 10.3390/pathogens13010020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/12/2023] [Accepted: 12/20/2023] [Indexed: 01/23/2024] Open
Abstract
The "Wattle and Daub" model of cyst wall formation in Entamoeba invadens has been used to explain encystment in Entamoeba histolytica, the causal agent of amoebiasis, and this process could be a potential target for new antiamoebic drugs. In this study, we studied the morphological stages of chitin wall formation in E. invadens in more detail using fluorescent chitin-binding dyes and the immunolocalization of cyst wall proteins. It was found that chitin deposition was mainly initiated on the cell surface at a specific point or at different points at the same time. The cystic wall grew outward and gradually covered the entire surface of the cyst over time, following the model of Wattle and Daub. The onset of chitin deposition was guided by the localization of chitin synthase 1 to the plasma membrane, occurring on the basis of the Jacob lectin in the cell membrane. During encystation, F-actin was reorganized into the cortical region within the early stages of encystation and remained intact until the completion of the chitin wall. The disruption of actin polymerization in the cortical region inhibited proper wall formation, producing wall-less cysts or cysts with defective chitin walls, indicating the importance of the cortical actin cytoskeleton for proper cyst wall formation.
Collapse
Affiliation(s)
| | | | | | - Sudip K. Ghosh
- Department of Bioscience and Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India; (D.K.); (M.P.); (S.N.)
| |
Collapse
|
2
|
Guillén N. Pathogenicity and virulence of Entamoeba histolytica, the agent of amoebiasis. Virulence 2023; 14:2158656. [PMID: 36519347 DOI: 10.1080/21505594.2022.2158656] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022] Open
Abstract
The amoeba parasite Entamoeba histolytica is the causative agent of human amebiasis, an enteropathic disease affecting millions of people worldwide. This ancient protozoan is an elementary example of how parasites evolve with humans, e.g. taking advantage of multiple mechanisms to evade immune responses, interacting with microbiota for nutritional and protective needs, utilizing host resources for growth, division, and encystation. These skills of E. histolytica perpetuate the species and incidence of infection. However, in 10% of infected cases, the parasite turns into a pathogen; the host-parasite equilibrium is then disorganized, and the simple lifecycle based on two cell forms, trophozoites and cysts, becomes unbalanced. Trophozoites acquire a virulent phenotype which, when non-controlled, leads to intestinal invasion with the onset of amoebiasis symptoms. Virulent E. histolytica must cross mucus, epithelium, connective tissue and possibly blood. This highly mobile parasite faces various stresses and a powerful host immune response, with oxidative stress being a challenge for its survival. New emerging research avenues and omics technologies target gene regulation to determine human or parasitic factors activated upon infection, their role in virulence activation, and in pathogenesis; this research bears in mind that E. histolytica is a resident of the complex intestinal ecosystem. The goal is to eradicate amoebiasis from the planet, but the parasitic life of E. histolytica is ancient and complex and will likely continue to evolve with humans. Advances in these topics are summarized here.
Collapse
Affiliation(s)
- Nancy Guillén
- Cell Biology and Infection Department, Institut Pasteur and Centre National de la Recherche Scientifique CNRS-ERM9195, Paris, France
| |
Collapse
|
3
|
Díaz-Hernández M, Javier-Reyna R, Martínez-Valencia D, Montaño S, Orozco E. Dynamic Association of ESCRT-II Proteins with ESCRT-I and ESCRT-III Complexes during Phagocytosis of Entamoeba histolytica. Int J Mol Sci 2023; 24:ijms24065267. [PMID: 36982336 PMCID: PMC10049522 DOI: 10.3390/ijms24065267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/10/2023] [Accepted: 02/13/2023] [Indexed: 03/12/2023] Open
Abstract
By their active movement and voraux phagocytosis, the trophozoites of Entamoeba histolytica constitute an excellent system to investigate the dynamics of the Endosomal Sorting Complex Required for Transport (ESCRT) protein interactions through phagocytosis. Here, we studied the proteins forming the E. histolytica ESCRT-II complex and their relationship with other phagocytosis-involved molecules. Bioinformatics analysis predicted that EhVps22, EhVps25, and EhVps36 are E. histolytica bona fide orthologues of the ESCRT-II protein families. Recombinant proteins and specific antibodies revealed that ESCRT-II proteins interact with each other, with other ESCRT proteins, and phagocytosis-involved molecules, such as the adhesin (EhADH). Laser confocal microscopy, pull-down assays, and mass spectrometry analysis disclosed that during phagocytosis, ESCRT-II accompanies the red blood cells (RBCs) from their attachment to the trophozoites until their arrival to multivesicular bodies (MVBs), changing their interactive patterns according to the time and place of the process. Knocked-down trophozoites in the Ehvps25 gene presented a 50% lower rate of phagocytosis than the controls and lower efficiency to adhere RBCs. In conclusion, ESCRT-II interacts with other molecules during prey contact and conduction throughout the phagocytic channel and trophozoites membranous system. ESCRT-II proteins are members of the protein chain during vesicle trafficking and are fundamental for the continuity and efficiency of phagocytosis.
Collapse
Affiliation(s)
- Mitzi Díaz-Hernández
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, México City 07360, Mexico
| | - Rosario Javier-Reyna
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, México City 07360, Mexico
| | - Diana Martínez-Valencia
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, México City 07360, Mexico
| | - Sarita Montaño
- Laboratorio de Modelado Molecular y Bioinformática, Facultad de Ciencias Químico-Biológicas, Universidad Autónoma de Sinaloa, Ciudad Universitaria s/n, Culiacán 80010, Mexico
| | - Esther Orozco
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, México City 07360, Mexico
- Correspondence:
| |
Collapse
|
4
|
Bello F, Orozco E, Benítez-Cardoza CG, Zamorano-Carrillo A, Reyes-López CA, Pérez-Ishiwara DG, Gómez-García C. The novel EhHSTF7 transcription factor displays an oligomer state and recognizes a heat shock element in the Entamoeba histolytica parasite. Microb Pathog 2021; 162:105349. [PMID: 34864144 DOI: 10.1016/j.micpath.2021.105349] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 12/01/2021] [Accepted: 12/01/2021] [Indexed: 01/09/2023]
Abstract
The heat shock response is a conserved mechanism that allows cells to respond and survive stress damage and is transcriptionally regulated by the heat shock factors and heat shock elements. The P-glycoprotein confer the multidrug resistance phenotype; Entamoeba histolytica has the largest multidrug resistance gene family described so far; one of these genes, the EhPgp5 gene, has an emetine-inducible expression. A functional heat shock element was localized in the EhPgp5 gene promoter, indicating transcriptional regulation by heat shock factors. In this work, we determined the oligomer state of EhHSTF7 and the recognition of the heat shock element of the EhPgp5 gene. The EhHSTF7 recombinant protein was obtained as monomer and oligomer. In silico molecular docking predicts protein-DNA binding between EhHSTF7 and 5'-GAA-3' complementary bases. The rEhHSTF7 protein specifically binds to the heat shock element of the EhPgp5 gene in gel shift assays. The competition assays with heat shock element mutants indicate that 5'-GAA-3' complementary bases are necessary for the rEhHSTF7 binding. Finally, the siRNA-mediated knockdown of Ehhstf7 expression causes downregulation of EhPgp5 expression, suggesting that EhHSTF7 is likely to play a key role in the E. histolytica multidrug resistance. This is the first report of a transcription factor that recognizes a heat shock element from a gene involved in drug resistance in parasites. However, further analysis needs to demonstrate the biological relevance of the EhHSTF7 and the rest of the heat shock factors of E. histolytica, to understand the underlying regulation of transcriptional control in response to stress.
Collapse
Affiliation(s)
- Fabiola Bello
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Instituto Politécnico Nacional 2508, San Pedro Zacatenco, Gustavo A. Madero, 07360, Mexico City, Mexico
| | - Esther Orozco
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Instituto Politécnico Nacional 2508, San Pedro Zacatenco, Gustavo A. Madero, 07360, Mexico City, Mexico
| | - Claudia G Benítez-Cardoza
- Programa Institucional en Biomedicina Molecular, Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Guillermo Massieu Helguera 239, La Escalera, Gustavo A. Madero, 07320, Mexico City, Mexico
| | - Absalom Zamorano-Carrillo
- Programa Institucional en Biomedicina Molecular, Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Guillermo Massieu Helguera 239, La Escalera, Gustavo A. Madero, 07320, Mexico City, Mexico
| | - César A Reyes-López
- Programa Institucional en Biomedicina Molecular, Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Guillermo Massieu Helguera 239, La Escalera, Gustavo A. Madero, 07320, Mexico City, Mexico
| | - D Guillermo Pérez-Ishiwara
- Programa Institucional en Biomedicina Molecular, Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Guillermo Massieu Helguera 239, La Escalera, Gustavo A. Madero, 07320, Mexico City, Mexico
| | - Consuelo Gómez-García
- Programa Institucional en Biomedicina Molecular, Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Guillermo Massieu Helguera 239, La Escalera, Gustavo A. Madero, 07320, Mexico City, Mexico.
| |
Collapse
|
5
|
Velle KB, Fritz-Laylin LK. Conserved actin machinery drives microtubule-independent motility and phagocytosis in Naegleria. J Cell Biol 2020; 219:e202007158. [PMID: 32960946 PMCID: PMC7594500 DOI: 10.1083/jcb.202007158] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/11/2020] [Accepted: 08/14/2020] [Indexed: 12/11/2022] Open
Abstract
Much of our understanding of actin-driven phenotypes in eukaryotes has come from the "yeast-to-human" opisthokont lineage and the related amoebozoa. Outside of these groups lies the genus Naegleria, which shared a common ancestor with humans >1 billion years ago and includes the "brain-eating amoeba." Unlike nearly all other known eukaryotic cells, Naegleria amoebae lack interphase microtubules; this suggests that actin alone drives phenotypes like cell crawling and phagocytosis. Naegleria therefore represents a powerful system to probe actin-driven functions in the absence of microtubules, yet surprisingly little is known about its actin cytoskeleton. Using genomic analysis, microscopy, and molecular perturbations, we show that Naegleria encodes conserved actin nucleators and builds Arp2/3-dependent lamellar protrusions. These protrusions correlate with the capacity to migrate and eat bacteria. Because human cells also use Arp2/3-dependent lamellar protrusions for motility and phagocytosis, this work supports an evolutionarily ancient origin for these processes and establishes Naegleria as a natural model system for studying microtubule-independent cytoskeletal phenotypes.
Collapse
|
6
|
Rath PP, Gourinath S. The actin cytoskeleton orchestra in Entamoeba histolytica. Proteins 2020; 88:1361-1375. [PMID: 32506560 DOI: 10.1002/prot.25955] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/17/2020] [Accepted: 05/27/2020] [Indexed: 12/14/2022]
Abstract
Years of evolution have kept actin conserved throughout various clades of life. It is an essential protein starring in many cellular processes. In a primitive eukaryote named Entamoeba histolytica, actin directs the process of phagocytosis. A finely tuned coordination between various actin-binding proteins (ABPs) choreographs this process and forms one of the virulence factors for this protist pathogen. The ever-expanding world of ABPs always has space to accommodate new and varied types of proteins to the earlier existing repertoire. In this article, we report the identification of 390 ABPs from Entamoeba histolytica. These proteins are part of diverse families that have been known to regulate actin dynamics. Most of the proteins are primarily uncharacterized in this organism; however, this study aims to annotate the ABPs based on their domain arrangements. A unique characteristic about some of the ABPs found is the combination of domains present in them unlike any other reported till date. Calponin domain-containing proteins formed the largest group among all types with 38 proteins, followed by 29 proteins with the infamous BAR domain in them, and 23 proteins belonging to actin-related proteins. The other protein families had a lesser number of members. Presence of exclusive domain arrangements in these proteins could guide us to yet unknown actin regulatory mechanisms prevalent in nature. This article is the first step to unraveling them.
Collapse
|
7
|
Morphological and Motility Features of the Stable Bleb-Driven Monopodial Form of Entamoeba and Its Importance in Encystation. Infect Immun 2020; 88:IAI.00903-19. [PMID: 32393510 DOI: 10.1128/iai.00903-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 04/27/2020] [Indexed: 11/20/2022] Open
Abstract
Entamoeba histolytica and its reptilian counterpart and encystation model Entamoeba invadens formed a polarized monopodial morphology when treated with pentoxifylline. This morphology was propelled by retrograde flow of the cell surface resulting from a cyclic sol-gel conversion of cytoplasm and a stable bleb at the leading edge. Pentoxifylline treatment switched the unpolarized, adherent trophozoites to the nonadherent, stable bleb-driven form and altered the motility pattern from slow and random to fast, directionally persistent, and highly chemotactic. Interestingly, exogenously added adenosine produced multiple protrusions and random motility, an opposite phenotype to that of pentoxifylline. Thus, pentoxifylline, an adenosine antagonist, may be inducing the monopodial morphology by preventing lateral protrusions and restricting the leading edge to one site. The polarized form of E. invadens was aggregation competent, and time-lapse microscopy of encystation revealed its appearance during early hours, mediating the cell aggregation by directional cell migration. The addition of purine nucleotides to in vitro encystation culture prevented the formation of polarized morphology and inhibited the cell aggregation and, thus, the encystation, which further showed the importance of the polarized form in the Entamoeba life cycle. Cell polarity and motility are essential in the pathogenesis of Entamoeba parasites, and the stable bleb-driven polarized morphology of Entamoeba may also be important in invasive amoebiasis.
Collapse
|
8
|
Hernández‐Cuevas NA, Jhingan GD, Petropolis D, Vargas M, Guillen N. Acetylation is the most abundant actin modification in
Entamoeba histolytica
and modifications of actin's amino‐terminal domain change cytoskeleton activities. Cell Microbiol 2018; 21:e12983. [DOI: 10.1111/cmi.12983] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 09/27/2018] [Accepted: 10/30/2018] [Indexed: 12/16/2022]
Affiliation(s)
| | | | - Debora Petropolis
- Institut Pasteur Unité Biologie Cellulaire du Parasitisme Paris France
- INSERM Unit 786 Paris France
| | - Miguel Vargas
- Departamento de Biomedicina Molecular Instituto Politécnico Nacional, Centro de Investigación y de Estudios Avanzados CINVESTAV Mexico City Mexico
| | - Nancy Guillen
- Institut Pasteur Unité Biologie Cellulaire du Parasitisme Paris France
- INSERM Unit 786 Paris France
- Centre National de la Recherche Scientifique, ERL9195 Paris France
| |
Collapse
|
9
|
Manich M, Hernandez-Cuevas N, Ospina-Villa JD, Syan S, Marchat LA, Olivo-Marin JC, Guillén N. Morphodynamics of the Actin-Rich Cytoskeleton in Entamoeba histolytica. Front Cell Infect Microbiol 2018; 8:179. [PMID: 29896453 PMCID: PMC5986921 DOI: 10.3389/fcimb.2018.00179] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 05/09/2018] [Indexed: 02/01/2023] Open
Abstract
Entamoeba histolytica is the anaerobic protozoan parasite responsible for human amoebiasis, the third most deadly parasitic disease worldwide. This highly motile eukaryotic cell invades human tissues and constitutes an excellent experimental model of cell motility and cell shape deformation. The absence of extranuclear microtubules in Entamoeba histolytica means that the actin-rich cytoskeleton takes on a crucial role in not only amoebic motility but also other processes sustaining pathogenesis, such as the phagocytosis of human cells and the parasite's resistance of host immune responses. Actin is highly conserved among eukaryotes, although diverse isoforms exist in almost all organisms studied to date. However, E. histolytica has a single actin protein, the structure of which differs significantly from those of its human homologs. Here, we studied the expression, structure and dynamics of actin in E. histolytica. We used molecular and cellular approaches to evaluate actin gene expression during intestinal invasion by E. histolytica trophozoites. Based on a three-dimensional structural bioinformatics analysis, we characterized protein domains differences between amoebic actin and human actin. Fine-tuned molecular dynamics simulations enabled us to examine protein motion and refine the three-dimensional structures of both actins, including elements potentially accounting for differences changes in the affinity properties of amoebic actin and deoxyribonuclease I. The dynamic, multifunctional nature of the amoebic cytoskeleton prompted us to examine the pleiotropic forms of actin structures within live E. histolytica cells; we observed the cortical cytoskeleton, stress fibers, "dot-like" structures, adhesion plates, and macropinosomes. In line with these data, a proteomics study of actin-binding proteins highlighted the Arp2/3 protein complex as a crucial element for the development of macropinosomes and adhesion plaques.
Collapse
Affiliation(s)
- Maria Manich
- BioImaging Unit, Institut Pasteur, Paris, France.,Cell Biology of Parasitism Unit, Institut Pasteur, Paris, France
| | | | - Juan D Ospina-Villa
- Instituto Politécnico Nacional, Escuela Nacional de Medicina y Homeopatía, Mexico City, Mexico
| | - Sylvie Syan
- Cell Biology of Parasitism Unit, Institut Pasteur, Paris, France
| | - Laurence A Marchat
- Instituto Politécnico Nacional, Escuela Nacional de Medicina y Homeopatía, Mexico City, Mexico
| | | | - Nancy Guillén
- Cell Biology of Parasitism Unit, Institut Pasteur, Paris, France.,Centre National de la Recherche Scientifique, CNRS-ERL9195, Paris, France
| |
Collapse
|
10
|
Ospina-Villa JD, Dufour A, Weber C, Ramirez-Moreno E, Zamorano-Carrillo A, Guillen N, Lopez-Camarillo C, Marchat LA. Targeting the polyadenylation factor EhCFIm25 with RNA aptamers controls survival in Entamoeba histolytica. Sci Rep 2018; 8:5720. [PMID: 29632392 PMCID: PMC5890266 DOI: 10.1038/s41598-018-23997-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 03/23/2018] [Indexed: 12/26/2022] Open
Abstract
Messenger RNA 3'-end polyadenylation is an important regulator of gene expression in eukaryotic cells. In our search for new ways of treating parasitic infectious diseases, we looked at whether or not alterations in polyadenylation might control the survival of Entamoeba histolytica (the agent of amoebiasis in humans). We used molecular biology and computational tools to characterize the mRNA cleavage factor EhCFIm25, which is essential for polyadenylation in E. histolytica. By using a strategy based on the systematic evolution of ligands by exponential enrichment, we identified single-stranded RNA aptamers that target EhCFIm25. The results of RNA-protein binding assays showed that EhCFIm25 binds to the GUUG motif in vitro, which differs from the UGUA motif bound by the homologous human protein. Accordingly, docking experiments and molecular dynamic simulations confirmed that interaction with GUUG stabilizes EhCFIm25. Incubating E. histolytica trophozoites with selected aptamers inhibited parasite proliferation and rapidly led to cell death. Overall, our data indicate that targeting EhCFIm25 is an effective way of limiting the growth of E. histolytica in vitro. The present study is the first to have highlighted the potential value of RNA aptamers for controlling this human pathogen.
Collapse
Affiliation(s)
- Juan David Ospina-Villa
- Instituto Politécnico Nacional, Escuela Nacional de Medicina y Homeopatía, Guillermo Massieu Helguera 239, Fracc. La Escalera Ticoman, CP 07320, Ciudad de México, Mexico
| | - Alexandre Dufour
- Institut Pasteur, Unité d'Analyse d'Images Biologiques, 25 Rue du Dr Roux, F-75015, Paris, France
- Centre National de la Recherche Scientifique CNRS UMR 3691, 25 Rue du Dr Roux, F-75015, Paris, France
| | - Christian Weber
- Centre National de la Recherche Scientifique CNRS UMR 3691, 25 Rue du Dr Roux, F-75015, Paris, France
- Institut Pasteur, Unité d'Imagerie et Modélisation, 28 rue du Docteur Roux, 75015, Paris, France
| | - Esther Ramirez-Moreno
- Instituto Politécnico Nacional, Escuela Nacional de Medicina y Homeopatía, Guillermo Massieu Helguera 239, Fracc. La Escalera Ticoman, CP 07320, Ciudad de México, Mexico
| | - Absalom Zamorano-Carrillo
- Instituto Politécnico Nacional, Escuela Nacional de Medicina y Homeopatía, Guillermo Massieu Helguera 239, Fracc. La Escalera Ticoman, CP 07320, Ciudad de México, Mexico
| | - Nancy Guillen
- Centre National de la Recherche Scientifique, CNRS-ERL9195, 25 Rue du Dr Roux, F-75015, Paris, France
| | - César Lopez-Camarillo
- Universidad Autónoma de la Ciudad de México, Posgrado en Ciencias Genómicas, San Lorenzo 290, Col. Del Valle, CP 03100, Ciudad de México, Mexico
| | - Laurence A Marchat
- Instituto Politécnico Nacional, Escuela Nacional de Medicina y Homeopatía, Guillermo Massieu Helguera 239, Fracc. La Escalera Ticoman, CP 07320, Ciudad de México, Mexico.
| |
Collapse
|
11
|
Boquet-Pujadas A, Lecomte T, Manich M, Thibeaux R, Labruyère E, Guillén N, Olivo-Marin JC, Dufour AC. BioFlow: a non-invasive, image-based method to measure speed, pressure and forces inside living cells. Sci Rep 2017; 7:9178. [PMID: 28835648 PMCID: PMC5569094 DOI: 10.1038/s41598-017-09240-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 07/19/2017] [Indexed: 12/23/2022] Open
Abstract
Cell motility is governed by a complex molecular machinery that converts physico-chemical cues into whole-cell movement. Understanding the underlying biophysical mechanisms requires the ability to measure physical quantities inside the cell in a simple, reproducible and preferably non-invasive manner. To this end, we developed BioFlow, a computational mechano-imaging method and associated software able to extract intracellular measurements including pressure, forces and velocity everywhere inside freely moving cells in two and three dimensions with high spatial resolution in a non-invasive manner. This is achieved by extracting the motion of intracellular material observed using fluorescence microscopy, while simultaneously inferring the parameters of a given theoretical model of the cell interior. We illustrate the power of BioFlow in the context of amoeboid cell migration, by modelling the intracellular actin bulk flow of the parasite Entamoeba histolytica using fluid dynamics, and report unique experimental measures that complement and extend both theoretical estimations and invasive experimental measures. Thanks to its flexibility, BioFlow is easily adaptable to other theoretical models of the cell, and alleviates the need for complex or invasive experimental conditions, thus constituting a powerful tool-kit for mechano-biology studies. BioFlow is open-source and freely available via the Icy software.
Collapse
Affiliation(s)
- Aleix Boquet-Pujadas
- Institut Pasteur, Bioimage Analysis Unit, Paris, France.,CNRS UMR3691, Paris, France
| | - Timothée Lecomte
- Institut Pasteur, Bioimage Analysis Unit, Paris, France.,CNRS UMR3691, Paris, France
| | - Maria Manich
- Institut Pasteur, Bioimage Analysis Unit, Paris, France.,CNRS UMR3691, Paris, France
| | - Roman Thibeaux
- Institut Pasteur, Cell Biology of Parasitism Unit, Paris, France.,INSERM U786, Paris, France.,Institut Pasteur, Leptospirosis Research Unit, New Caledonia
| | - Elisabeth Labruyère
- Institut Pasteur, Bioimage Analysis Unit, Paris, France.,CNRS UMR3691, Paris, France
| | - Nancy Guillén
- Institut Pasteur, Cell Biology of Parasitism Unit, Paris, France.,INSERM U786, Paris, France.,CNRS ERL9195, Paris, France
| | | | - Alexandre C Dufour
- Institut Pasteur, Bioimage Analysis Unit, Paris, France. .,CNRS UMR3691, Paris, France.
| |
Collapse
|
12
|
Liu XJ, Xie L, Liu N, Zhan S, Zhou XG, Wang Q. RNA interference unveils the importance of Pseudotrichonympha grassii cellobiohydrolase, a protozoan exoglucanase, in termite cellulose degradation. INSECT MOLECULAR BIOLOGY 2017; 26:233-242. [PMID: 27991709 DOI: 10.1111/imb.12287] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Based on prior work, a cellulase from glycosyl hydrolase family 7 (GHF7) was identified and found to be expressed at a high level in Coptotermes formosanus. To determine the function of GHF7 family members in vivo, we used RNA interference (RNAi) to functionally analyse the exoglucanase gene Pseudotrichonympha grassii cellobiohydrolase gene (PgCBH), which was highly expressed in Pseudotrichonympha grassii, a flagellate found in the hindgut of C. formosanus. In this study, the expression level of PgCBH was down-regulated by RNAi, causing the death of P. grassii, but no effect was observed for other flagellates found in C. formosanus. RNAi also resulted in significantly reduced exoglucanase activity, and no effect was observed for endoglucanase and β-glucosidase activities. This result demonstrated that the PgCBH gene plays a role in the protist lignocellulolytic process and is also important for host survival. PgCBH can be used as a target gene and has potential as a bioinsecticide for use against termites.
Collapse
Affiliation(s)
- X-J Liu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Shanghai, China
| | - L Xie
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Shanghai, China
| | - N Liu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Shanghai, China
| | - S Zhan
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - X-G Zhou
- Department of Entomology, University of Kentucky, KY, USA
| | - Q Wang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| |
Collapse
|
13
|
Gómez-Conde E, Vargas-Mejía MÁ, Díaz-Orea MA, Hernández-Rivas R, Cárdenas-Perea ME, Guerrero-González T, González-Barrios JA, Montiel-Jarquín ÁJ. Detection of beta-tubulin in the cytoplasm of the interphasic Entamoeba histolytica trophozoites. Exp Parasitol 2016; 167:38-42. [PMID: 27156446 DOI: 10.1016/j.exppara.2016.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 03/17/2016] [Accepted: 05/05/2016] [Indexed: 10/21/2022]
Abstract
It is known that the microtubules (MT) of Entamoeba histolytica trophozoites form an intranuclear mitotic spindle. However, electron microscopy studies and the employment of anti-beta-tubulin (β-tubulin) antibodies have not exhibited these cytoskeletal structures in the cytoplasm of these parasites. The purpose of this work was to detect β-tubulin in the cytoplasm of interphasic E. histolytica trophozoites. Activated or non-activated HMI-IMSS-strain E. histolytica trophozoites were used and cultured for 72 h at 37 °C in TYI-S-33 medium, and then these were incubated with the anti-β-tubulin antibody of E. histolytica. The anti-β-tubulin antibody reacted with the intranuclear mitotic spindle of E. histolytica-activated trophozoites as control. In contrast, in non-activated interphasic parasites, anti-β-tubulin antibody reacted with diverse puntiform structures in the cytoplasm and with ring-shaped structures localized in the cytoplasm, cellular membrane and endocytic stomas. In this work, for the first time, the presence of β-tubulin is shown in the cytoplasm of E. histolytica trophozoites.
Collapse
Affiliation(s)
- Eduardo Gómez-Conde
- División de Investigación en Salud, Unidad Médica de Alta Especialidad (UMAE), Hospital de Especialidades, Centro Médico Nacional General de División "Manuel Ávila Camacho", Instituto Mexicano del Seguro Social (IMSS), Calle 2 Norte 2004, Col. Centro, 72000 Puebla, Mexico; Laboratorio de Investigación en Inmunobiología, Facultad de Medicina, Benemérita Universidad Autónoma de Puebla (BUAP), Calle 13 Sur 2706, Col. Volcanes, 72410 Puebla, Mexico.
| | - Miguel Ángel Vargas-Mejía
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Av. Instituto Politécnico Nacional 2508, Delegación Gustavo A. Madero, Col.San Pedro Zacatenco, 07360 México, D.F., Mexico.
| | - María Alicia Díaz-Orea
- Laboratorio de Investigación en Inmunobiología, Facultad de Medicina, Benemérita Universidad Autónoma de Puebla (BUAP), Calle 13 Sur 2706, Col. Volcanes, 72410 Puebla, Mexico.
| | - Rosaura Hernández-Rivas
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Av. Instituto Politécnico Nacional 2508, Delegación Gustavo A. Madero, Col.San Pedro Zacatenco, 07360 México, D.F., Mexico.
| | - María Elena Cárdenas-Perea
- Laboratorio de Investigación en Inmunobiología, Facultad de Medicina, Benemérita Universidad Autónoma de Puebla (BUAP), Calle 13 Sur 2706, Col. Volcanes, 72410 Puebla, Mexico.
| | - Tayde Guerrero-González
- Servicio de Traumatología y Ortopedia, Hospital Regional 1(o) de Octubre, Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado (ISSSTE), Av. Instituto Politécnico Nacional 1669, Gustavo A. Madero, Col. Magdalena de las Salinas, Del. Gustavo A. Madero, 07760 México D.F., Mexico.
| | - Juan Antonio González-Barrios
- Laboratorio de Medicina Genómica, Hospital Regional 1 de Octubre, Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado (ISSSTE), Avenida Instituto Politécnico Nacional N° 1669, Gustavo A. Madero, Col. Magdalena de las Salinas, Del. Gustavo A. Madero, 07760 México, D.F., Mexico.
| | - Álvaro José Montiel-Jarquín
- Jefatura de División de Investigación en Salud, UMAE, Hospital de Traumatología, Instituto Mexicano del Seguro Social, Diagonal Defensores de la República y 6 Poniente, Col. Amor, 72140 Puebla, Mexico.
| |
Collapse
|
14
|
Liu YC, Singh U. Destabilization domain approach adapted for regulated protein expression in the protozoan parasite Entamoeba histolytica. Int J Parasitol 2014; 44:729-35. [PMID: 24929134 DOI: 10.1016/j.ijpara.2014.05.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 04/29/2014] [Accepted: 05/01/2014] [Indexed: 02/04/2023]
Abstract
A plethora of information has been gained by sequencing the genome of the human parasite Entamoeba histolytica, however a lack of robust genetic tools hampers experimental elucidation of gene functions. We adapted the destabilization domain approach for modulation of protein levels in E. histolytica using the destabilization domains of FK506 binding protein (ddFKBP) and dihydrofolate reductase (ddDHFR), respectively. In our studies, the ddFKBP appears to be more tightly regulated than ddDHFR, with minimal detectable protein in trophozoites in the absence of the stabilizing compound. The on- and off-rate kinetics for ddFKBP were rapid, with stabilization and degradation within 3h of addition or removal of stabilizing compound, respectively. The kinetics for ddDHFR was different, with rapid stabilization (within 3h of stabilizing compound being added) but much slower degradation (protein not destabilized until 24h after compound removal). Furthermore, we demonstrated that for the ddFKBP, the standard stabilizing compound Shield-1 could be effectively replaced by two cheaper alternatives (rapamycin and FK506), indicating that the more cost-effective alternatives are viable options for use with E. histolytica. Thus, the destabilization domain approach represents a powerful method to study protein functions in E. histolytica and adds to the catalog of genetic tools that could be used to study this important human pathogen.
Collapse
Affiliation(s)
- Yuk-Chien Liu
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA
| | - Upinder Singh
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA.
| |
Collapse
|
15
|
Wrobel D, Kolanowska K, Gajek A, Gomez-Ramirez R, de la Mata J, Pedziwiatr-Werbicka E, Klajnert B, Waczulikova I, Bryszewska M. Interaction of cationic carbosilane dendrimers and their complexes with siRNA with erythrocytes and red blood cell ghosts. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1838:882-9. [PMID: 24316171 PMCID: PMC7094680 DOI: 10.1016/j.bbamem.2013.11.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 11/01/2013] [Accepted: 11/26/2013] [Indexed: 11/20/2022]
Abstract
We have investigated the interactions between cationic NN16 and BDBR0011 carbosilane dendrimers with red blood cells or their cell membranes. The carbosilane dendrimers used possess 16 cationic functional groups. Both the dendrimers are made of water-stable carbon-silicon bonds, but NN16 possesses some oxygen-silicon bonds that are unstable in water. The nucleic acid used in the experiments was targeted against GAG-1 gene from the human immunodeficiency virus, HIV-1. By binding to the outer leaflet of the membrane, carbosilane dendrimers decreased the fluidity of the hydrophilic part of the membrane but increased the fluidity of the hydrophobic interior. They induced hemolysis, but did not change the morphology of the cells. Increasing concentrations of dendrimers induced erythrocyte aggregation. Binding of short interfering ribonucleic acid (siRNA) to a dendrimer molecule decreased the availability of cationic groups and diminished their cytotoxicity. siRNA-dendrimer complexes changed neither the fluidity of biological membranes nor caused cell hemolysis. Addition of dendriplexes to red blood cell suspension induced echinocyte formation.
Collapse
Affiliation(s)
- Dominika Wrobel
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland.
| | - Katarzyna Kolanowska
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Arkadiusz Gajek
- Department of Thermobiology, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | | | - Javier de la Mata
- Departamento Quimica Inorganica, Universidad de Alcala de Henares, Spain
| | - Elżbieta Pedziwiatr-Werbicka
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Barbara Klajnert
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Iveta Waczulikova
- Faculty of Mathematics, Physics and Informatics, Comenius University, Bratislava, Slovakia
| | - Maria Bryszewska
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| |
Collapse
|
16
|
López-Camarillo C, López-Rosas I, Ospina-Villa JD, Marchat LA. Deciphering molecular mechanisms of mRNA metabolism in the deep-branching eukaryote Entamoeba histolytica. WILEY INTERDISCIPLINARY REVIEWS. RNA 2014; 5:247-262. [PMID: 24249245 DOI: 10.1002/wrna.1205] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 10/04/2013] [Accepted: 10/09/2013] [Indexed: 03/10/2025]
Abstract
Although extraordinary rapid advance has been made in the knowledge of mechanisms regulating messenger RNA (mRNA) metabolism in mammals and yeast, little information is known in deep-branching eukaryotes. The complete genome sequence of Entamoeba histolytica, the protozoan parasite responsible for human amoebiasis, provided a lot of information for the identification and comparison of regulatory sequences and proteins potentially involved in mRNA synthesis, processing, and degradation. Here, we review the current knowledge of mRNA metabolism in this human pathogen. Several DNA motifs in promoter and nuclear factors involved in transcription, as well as conserved polyadenylation sequences in mRNA 3'-untranslated region and possible cleavage and polyadenylation factors, are described. In addition, we present recent data about proteins involved in mRNA decay with a special focus on the recently reported P-bodies in amoeba. Models for mechanisms of decapping and deadenylation-dependent pathways are discussed. We also review RNA-based gene silencing mechanisms and describe the DEAD/DExH box RNA helicases that are molecular players in all mRNA metabolism reactions. The functional characterization of selected proteins allows us to define a general framework to describe how mRNA synthesis, processing, and decay may occur in E. histolytica. Taken altogether, studies of mRNA metabolism in this single-celled eukaryotic model suggest the conservation of specific gene expression regulatory events through evolution.
Collapse
Affiliation(s)
- César López-Camarillo
- Genomics Sciences Program, Autonomous University of Mexico City, Mexico City, Mexico
| | | | | | | |
Collapse
|
17
|
Ocádiz-Ruiz R, Fonseca W, Martínez MB, Ocádiz-Quintanar R, Orozco E, Rodríguez MA. Effect of the silencing of the Ehcp112 gene on the in vitro virulence of Entamoeba histolytica. Parasit Vectors 2013; 6:248. [PMID: 23981435 PMCID: PMC3765809 DOI: 10.1186/1756-3305-6-248] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Accepted: 08/24/2013] [Indexed: 11/28/2022] Open
Abstract
Background Entamoeba histolytica is an intestinal protozoan parasite that causes amoebiasis in humans, affecting up to 50 million people worldwide each year and causing 40,000 to 100,000 deaths annually. EhCP112 is a cysteine proteinase of E. histolytica able to disrupt cell monolayers and digest extracellular matrix proteins, it is secreted by trophozoites and it can be active in a wide range of temperature and pH. These characteristics have encouraged the use of EhCP112 in the design and production of possible vaccines against amoebiasis, obtaining promising results. Nevertheless, we have no conclusive information about the role of EhCP112 in the E. histolytica pathogenesis. Methods A set of three specific siRNA sequences were used to silence the Ehcp112 gene via the soaking system. Silencing was evaluated by Western blot using an antibody against the EhCP112 recombinant protein. Finally, we analyzed the protease activity, the phagocytosis rate and the ability to destroy MDCK cells of the EhCP112-silenced trophozoites. Results The highest silencing effect on EhCP112 was detected at 16 h of treatment; time enough to perform the in vitro virulence assays, which showed that EhCP112 silencing produces a significant reduction in cytolysis and phagocytosis of target cells, indicating the participation of this proteinase in these events. Conclusions EhCP112 is involved in the in vitro virulence of E. histolytica.
Collapse
Affiliation(s)
- Ramón Ocádiz-Ruiz
- Departamento de Infectómica y Patogénesis Molecular, CINVESTAV-IPN, A,P, 14-740, México, D,F,, México.
| | | | | | | | | | | |
Collapse
|
18
|
Zhang H, Ehrenkaufer GM, Hall N, Singh U. Small RNA pyrosequencing in the protozoan parasite Entamoeba histolytica reveals strain-specific small RNAs that target virulence genes. BMC Genomics 2013; 14:53. [PMID: 23347563 PMCID: PMC3610107 DOI: 10.1186/1471-2164-14-53] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2012] [Accepted: 01/02/2013] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Small RNA mediated gene silencing is a well-conserved regulatory pathway. In the parasite Entamoeba histolytica an endogenous RNAi pathway exists, however, the depth and diversity of the small RNA population remains unknown. RESULTS To characterize the small RNA population that associates with E. histolytica Argonaute-2 (EhAGO2-2), we immunoprecipitated small RNAs that associate with it and performed one full pyrosequencing run. Data analysis revealed new features of the 27nt small RNAs including the 5'-G predominance, distinct small RNA distribution patterns on protein coding genes, small RNAs mapping to both introns and exon-exon junctions, and small RNA targeted genes that are clustered particularly in sections of genome duplication. Characterization of genomic loci to which both sense and antisense small RNAs mapped showed that both sets of small RNAs have 5'-polyphosphate termini; strand-specific RT-PCR detected transcripts in both directions at these loci suggesting that both transcripts may serve as template for small RNA generation. In order to determine whether small RNA abundance patterns account for strain-specific gene expression profiles of E. histolytica virulent and non-virulent strains, we sequenced small RNAs from a non-virulent strain and found that small RNAs mapped to genes in a manner consistent with their regulation of strain-specific virulence genes. CONCLUSIONS We provided a full spectrum analysis for E. histolytica AGO2-2 associated 27nt small RNAs. Additionally, comparative analysis of small RNA populations from virulent and non-virulent amebic strains indicates that small RNA populations may regulate virulence genes.
Collapse
Affiliation(s)
- Hanbang Zhang
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University School of Medicine, Stanford, California 94305-5107, USA
| | | | | | | |
Collapse
|
19
|
Silencing of Entamoeba histolytica glucosamine 6-phosphate isomerase by RNA interference inhibits the formation of cyst-like structures. BIOMED RESEARCH INTERNATIONAL 2013; 2013:758341. [PMID: 23484154 PMCID: PMC3581238 DOI: 10.1155/2013/758341] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Revised: 11/11/2012] [Accepted: 11/20/2012] [Indexed: 11/24/2022]
Abstract
Encystment is an essential process in the biological cycle of the human parasite Entamoeba histolytica. In the present study, we evaluated the participation of E. histolytica Gln6Pi in the formation of amoeba cyst-like structures by RNA interference assay. Amoeba trophozoites transfected with two Gln6Pi siRNAs reduced the expression of the enzyme in 85%, which was confirmed by western blot using an anti-Gln6Pi antibody. The E. histolytica Gln6Pi knockdown with the mix of both siRNAs resulted in the loss of its capacity to form cyst-like structures (CLSs) and develop a chitin wall under hydrogen peroxide treatment, as evidenced by absence of both resistance to detergent treatment and calcofluor staining. Thus, only 5% of treated trophozoites were converted to CLS, from which only 15% were calcofluor stained. These results represent an advance in the understanding of chitin biosynthesis in E. histolytica and provide insight into the encystment process in this parasite, which could allow for the developing of new control strategies for this parasite.
Collapse
|
20
|
Faust DM, Guillen N. Virulence and virulence factors in Entamoeba histolytica, the agent of human amoebiasis. Microbes Infect 2012; 14:1428-41. [DOI: 10.1016/j.micinf.2012.05.013] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 05/09/2012] [Accepted: 05/28/2012] [Indexed: 11/26/2022]
|
21
|
Mancilla-Herrera I, Méndez-Tenorio A, Wong-Baeza I, Jiménez-Uribe AP, Alcántara-Hernández M, Ocadiz-Ruiz R, Moreno-Eutimio MA, Arriaga-Pizano LA, López-Macías C, González-y-Merchand J, Isibasi A. A Toll/IL-1R/resistance domain-containing thioredoxin regulates phagocytosis in Entamoeba histolytica. Parasit Vectors 2012; 5:224. [PMID: 23043976 PMCID: PMC3481431 DOI: 10.1186/1756-3305-5-224] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 09/22/2012] [Indexed: 11/22/2022] Open
Abstract
Background Entamoeba histolytica is a protozoan parasite that infects humans and causes amebiasis affecting developing countries. Phagocytosis of epithelial cells, erythrocytes, leucocytes, and commensal microbiota bacteria is a major pathogenic mechanism used by this parasite. A Toll/IL-1R/Resistance (TIR) domain-containing protein is required in phagocytosis in the social ameba Dictyostelium discoideum, an ameba closely related to Entamoeba histolytica in phylogeny. In insects and vertebrates, TIR domain-containing proteins regulate phagocytic and cell activation. Therefore, we investigated whether E. histolytica expresses TIR domain-containing molecules that may be involved in the phagocytosis of erythrocytes and bacteria. Methods Using in silico analysis we explored in Entamoeba histolytica databases for TIR domain containing sequences. After silencing TIR domain containing sequences in trophozoites by siRNA we evaluated phagocytosis of erythrocytes and bacteria. Results We identified an E. histolytica thioredoxin containing a TIR-like domain. The secondary and tertiary structure of this sequence exhibited structural similarity to TIR domain family. Thioredoxin transcripts silenced in E. histolytica trophozoites decreased erythrocytes and E. coli phagocytosis. Conclusion TIR domain-containing thioredoxin of E. histolytica could be an important element in erythrocytes and bacteria phagocytosis.
Collapse
Affiliation(s)
- Ismael Mancilla-Herrera
- Medical Research Unit on Immunochemistry, Specialties Hospital, National Medical Centre Siglo XXI, Mexican Social Security Institute, Mexico City, Mexico
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Hirt RP, de Miguel N, Nakjang S, Dessi D, Liu YC, Diaz N, Rappelli P, Acosta-Serrano A, Fiori PL, Mottram JC. Trichomonas vaginalis pathobiology new insights from the genome sequence. ADVANCES IN PARASITOLOGY 2012; 77:87-140. [PMID: 22137583 DOI: 10.1016/b978-0-12-391429-3.00006-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The draft genome of the common sexually transmitted pathogen Trichomonas vaginalis encodes one of the largest known proteome with 60,000 candidate proteins. This provides parasitologists and molecular cell biologists alike with exciting, yet challenging, opportunities to unravel the molecular features of the parasite's cellular systems and potentially the molecular basis of its pathobiology. Here, recent investigations addressing selected aspects of the parasite's molecular cell biology are discussed, including surface and secreted virulent factors, membrane trafficking, cell signalling, the degradome, and the potential role of RNA interference in the regulation of gene expression.
Collapse
Affiliation(s)
- Robert P Hirt
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
RNA interference in protozoan parasites: achievements and challenges. EUKARYOTIC CELL 2011; 10:1156-63. [PMID: 21764910 DOI: 10.1128/ec.05114-11] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Protozoan parasites that profoundly affect mankind represent an exceptionally diverse group of organisms, including Plasmodium, Toxoplasma, Entamoeba, Giardia, trypanosomes, and Leishmania. Despite the overwhelming impact of these parasites, there remain many aspects to be discovered about mechanisms of pathogenesis and how these organisms survive in the host. Combined with the ever-increasing availability of sequenced genomes, RNA interference (RNAi), discovered a mere 13 years ago, has enormously facilitated the analysis of gene function, especially in organisms that are not amenable to classical genetic approaches. Here we review the current status of RNAi in studies of parasitic protozoa, with special emphasis on its use as a postgenomic tool.
Collapse
|
24
|
Zhang H, Pompey JM, Singh U. RNA interference in Entamoeba histolytica: implications for parasite biology and gene silencing. Future Microbiol 2011; 6:103-17. [PMID: 21162639 DOI: 10.2217/fmb.10.154] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Entamoeba histolytica is a major health threat to people in developing countries, where it causes invasive diarrhea and liver abscesses. The study of this important human pathogen has been hindered by a lack of tools for genetic manipulation. Recently, a number of genetic approaches based on variations of the RNAi method have been successfully developed and cloning of endogenous small-interfering RNAs from E. histolytica revealed an abundant population of small RNAs with an unusual 5´-polyphosphate structure. However, little is known about the implications of these findings to amebic biology or the mechanisms of gene silencing in this organism. In this article we review the literature relevant to RNAi in E. histolytica, discuss its implications for advances in gene silencing in this organism and outline potential future directions towards understanding the repertoire of RNAi and its impact on the biology of this deep-branching eukaryotic parasite.
Collapse
Affiliation(s)
- Hanbang Zhang
- Stanford University School of Medicine, S-143 Grant Building, 300 Pasteur Drive, Stanford, CA 94305, USA
| | | | | |
Collapse
|
25
|
Tovy A, Ankri S. Epigenetics in the unicellular parasite Entamoeba histolytica. Future Microbiol 2011; 5:1875-84. [PMID: 21198420 DOI: 10.2217/fmb.10.140] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Amoebiasis is a serious infectious disease that is caused by the unicellular parasite, Entamoeba histolytica. This parasite is mainly found in developing countries, and are named owing to its ability to destroy tissues. The molecular mechanisms that regulate the virulence of this parasite are not well understood. In recent years, an increasing interest in the epigenetic regulation of the parasite's virulence has emerged. In this article, an overview of our current knowledge about the role of DNA methylation, histone modifications and RNA-associated silencing in the biology of E. histolytica is provided. The relevance of some features of the parasite's unique epigenetic machinery to the development of new antiamoebic therapeutic molecules is discussed.
Collapse
Affiliation(s)
- Ayala Tovy
- Department of Microbiology, Ruth & Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology & the Rappaport Institute, Haifa, Israel
| | | |
Collapse
|
26
|
Chatterji BP, Jindal B, Srivastava S, Panda D. Microtubules as antifungal and antiparasitic drug targets. Expert Opin Ther Pat 2011; 21:167-86. [PMID: 21204724 DOI: 10.1517/13543776.2011.545349] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Diseases caused by fungi and parasites are major illnesses in humans as well as in animals. Microtubule-targeted drugs are highly effective for the treatment of fungal and parasitic infections; however, several human parasitic infections such as malaria, trypanosomiasis and leishmaniasis do not have effective remedial drugs. In addition, the emergence of drug-resistant fungi and parasites makes the discovery of new drugs imperative. AREAS COVERED This article describes similarities and dissimilarities between parasitic, fungal and mammalian tubulins and focuses on microtubule-targeting agents and therapeutic approaches for the treatment of fungal and parasitic diseases. New microtubule-targeted antileishmanial, antimalarial and antifungal drugs, with structures, biological activities and related patents, are described. The potential of dsRNA against tubulin to inhibit proliferation of protozoan and helminthic parasites is also discussed. Patent documents up to 2010 have been searched on USPTO, Patentscope, and Espacenet resources. EXPERT OPINION The article suggests that vaccination with tubulin may offer novel opportunities for the antiparasitic treatment. Native or recombinant tubulin used as antigen has been shown to elicit immune response and cure infection partially or fully in animals upon challenge by protozoan parasites and helminths, thus indicating the suitability of tubulin as a vaccine against parasitic diseases.
Collapse
Affiliation(s)
- Biswa Prasun Chatterji
- Indian Institute of Technology Bombay, Department of Biosciences and Bioengineering, Powai, Mumbai-400076, India
| | | | | | | |
Collapse
|
27
|
Cao H, Jiang X, Chai C, Chew SY. RNA interference by nanofiber-based siRNA delivery system. J Control Release 2010; 144:203-12. [DOI: 10.1016/j.jconrel.2010.02.003] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 01/03/2010] [Accepted: 02/01/2010] [Indexed: 01/08/2023]
|
28
|
Solis CF, Santi-Rocca J, Perdomo D, Weber C, Guillén N. Use of bacterially expressed dsRNA to downregulate Entamoeba histolytica gene expression. PLoS One 2009; 4:e8424. [PMID: 20037645 PMCID: PMC2793006 DOI: 10.1371/journal.pone.0008424] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2009] [Accepted: 11/24/2009] [Indexed: 11/18/2022] Open
Abstract
Background Modern RNA interference (RNAi) methodologies using small interfering RNA (siRNA) oligonucleotide duplexes or episomally synthesized hairpin RNA are valuable tools for the analysis of gene function in the protozoan parasite Entamoeba histolytica. However, these approaches still require time-consuming procedures including transfection and drug selection, or costly synthetic molecules. Principal Findings Here we report an efficient and handy alternative for E. histolytica gene down-regulation mediated by bacterial double-stranded RNA (dsRNA) targeting parasite genes. The Escherichia coli strain HT115 which is unable to degrade dsRNA, was genetically engineered to produce high quantities of long dsRNA segments targeting the genes that encode E. histolytica β-tubulin and virulence factor KERP1. Trophozoites cultured in vitro were directly fed with dsRNA-expressing bacteria or soaked with purified dsRNA. Both dsRNA delivery methods resulted in significant reduction of protein expression. In vitro host cell-parasite assays showed that efficient downregulation of kerp1 gene expression mediated by bacterial dsRNA resulted in significant reduction of parasite adhesion and lytic capabilities, thus supporting a major role for KERP1 in the pathogenic process. Furthermore, treatment of trophozoites cultured in microtiter plates, with a repertoire of eighty-five distinct bacterial dsRNA segments targeting E. histolytica genes with unknown function, led to the identification of three genes potentially involved in the growth of the parasite. Conclusions Our results showed that the use of bacterial dsRNA is a powerful method for the study of gene function in E. histolytica. This dsRNA delivery method is also technically suitable for the study of a large number of genes, thus opening interesting perspectives for the identification of novel drug and vaccine targets.
Collapse
Affiliation(s)
- Carlos F. Solis
- Institut Pasteur, Unité Biologie Cellulaire du Parasitisme, Paris, France
- INSERM U786, Paris, France
| | - Julien Santi-Rocca
- Institut Pasteur, Unité Biologie Cellulaire du Parasitisme, Paris, France
- INSERM U786, Paris, France
| | - Doranda Perdomo
- Institut Pasteur, Unité Biologie Cellulaire du Parasitisme, Paris, France
- INSERM U786, Paris, France
| | - Christian Weber
- Institut Pasteur, Unité Biologie Cellulaire du Parasitisme, Paris, France
- INSERM U786, Paris, France
| | - Nancy Guillén
- Institut Pasteur, Unité Biologie Cellulaire du Parasitisme, Paris, France
- INSERM U786, Paris, France
- * E-mail:
| |
Collapse
|
29
|
López-Fraga M, Martínez T, Jiménez A. RNA interference technologies and therapeutics: from basic research to products. BioDrugs 2009; 23:305-32. [PMID: 19754220 PMCID: PMC7099360 DOI: 10.2165/11318190-000000000-00000] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
RNA interference (RNAi) is a natural cellular process that regulates gene expression by a highly precise mechanism of sequence-directed gene silencing at the stage of translation by degrading specific messenger RNAs or blocking translation. In recent years, the use of RNAi for therapeutic applications has gained considerable momentum. It has been suggested that most of the novel disease-associated targets that have been identified are not ‘druggable’ with conventional approaches. However, any disease-causing gene and any cell type or tissue can potentially be targeted with RNAi. This review focuses on the current knowledge of RNAi mechanisms and the safety issues associated with its potential use in a therapeutic setting. Some of the most important aspects to consider when working towards the application of RNAi-based products in a clinical setting have been related to achieving high efficacies and enhanced stability profiles through a careful design of the nucleic acid sequence and the introduction of chemical modifications, but most of all, to developing improved delivery systems, both viral and non-viral. These new delivery systems allow for these products to reach the desired target cells, tissues or organs in a highly specific manner and after administration of the lowest possible doses. Various routes of application and target locations are currently being addressed in order to develop effective delivery systems for different targets and pathologies, including infectious pathologies, genetic pathologies and diseases associated with dysregulation of endogenous microRNAs. As with any new technology, several challenges and important aspects to be considered have risen on the road to clinical intervention, e.g. correct design of preclinical toxicology studies, regulatory concerns, and intellectual property protection. The main advantages related to the use of RNAi-based products in a clinical setting, and the latest clinical and preclinical studies using these compounds, are reviewed.
Collapse
|
30
|
Singh SK, Hajeri PB. siRNAs: their potential as therapeutic agents – Part II. Methods of delivery. Drug Discov Today 2009; 14:859-65. [DOI: 10.1016/j.drudis.2009.06.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2009] [Accepted: 06/08/2009] [Indexed: 12/11/2022]
|
31
|
Mukherjee C, Majumder S, Lohia A. Inter-cellular variation in DNA content of Entamoeba histolytica originates from temporal and spatial uncoupling of cytokinesis from the nuclear cycle. PLoS Negl Trop Dis 2009; 3:e409. [PMID: 19352422 PMCID: PMC2659751 DOI: 10.1371/journal.pntd.0000409] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Accepted: 03/11/2009] [Indexed: 11/19/2022] Open
Abstract
Accumulation of multiple copies of the genome in a single nucleus and several nuclei in a single cell has previously been noted in Entamoeba histolytica, contributing to the genetic heterogeneity of this unicellular eukaryote. In this study, we demonstrate that this genetic heterogeneity is an inherent feature of the cell cycle of this organism. Chromosome segregation occurs on a variety of novel microtubular assemblies including multi-polar spindles. Cytokinesis in E. histolytica is completed by the mechanical severing of a thin cytoplasmic bridge, either independently or with the help of neighboring cells. Importantly, cytokinesis is uncoupled from the nuclear division cycle, both temporally and spatially, leading to the formation of unequal daughter cells. Sorting of euploid and polyploid cells showed that each of these sub-populations acquired heterogeneous DNA content upon further growth. Our study conclusively demonstrates that genetic heterogeneity originates from the unique mode of cell division events in this protist. Proliferating eukaryotic cells regulate their DNA synthesis, chromosome segregation, and cell division with great precision so that daughter cells are genetically identical. Our study demonstrates that in proliferating cells of the protist pathogen Entamoeba histolytica re-duplication of DNA followed by segregation on atypical and diverse microtubular structures is frequently observed. In this parasite, cell division is erratic, so that each daughter cell may contain one or more nuclei and sometimes no nuclei. This uncoupling of cell cycle events and survival of daughter cells with unequal DNA contents leads to genetic heterogeneity in E. histolytica. Our study highlights the inherent plasticity of the Entamoeba genome and the ability of this protist to survive in the absence of strict regulatory mechanisms that are a hallmark of the eukaryotic cell cycle.
Collapse
Affiliation(s)
| | | | - Anuradha Lohia
- Department of Biochemistry, Bose Institute, Kolkata, India
- * E-mail:
| |
Collapse
|
32
|
Short hairpin RNA-mediated knockdown of protein expression in Entamoeba histolytica. BMC Microbiol 2009; 9:38. [PMID: 19222852 PMCID: PMC2652455 DOI: 10.1186/1471-2180-9-38] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2008] [Accepted: 02/17/2009] [Indexed: 12/15/2022] Open
Abstract
Background Entamoeba histolytica is an intestinal protozoan parasite of humans. The genome has been sequenced, but the study of individual gene products has been hampered by the lack of the ability to generate gene knockouts. We chose to test the use of RNA interference to knock down gene expression in Entamoeba histolytica. Results An episomal vector-based system, using the E. histolytica U6 promoter to drive expression of 29-basepair short hairpin RNAs, was developed to target protein-encoding genes in E. histolytica. The short hairpin RNAs successfully knocked down protein levels of all three unrelated genes tested with this system: Igl, the intermediate subunit of the galactose- and N-acetyl-D-galactosamine-inhibitable lectin; the transcription factor URE3-BP; and the membrane binding protein EhC2A. Igl levels were reduced by 72%, URE3-BP by 89%, and EhC2A by 97%. Conclusion Use of the U6 promoter to drive expression of 29-basepair short hairpin RNAs is effective at knocking down protein expression for unrelated genes in Entamoeba histolytica, providing a useful tool for the study of this parasite.
Collapse
|
33
|
Small RNAs with 5'-polyphosphate termini associate with a Piwi-related protein and regulate gene expression in the single-celled eukaryote Entamoeba histolytica. PLoS Pathog 2008; 4:e1000219. [PMID: 19043551 PMCID: PMC2582682 DOI: 10.1371/journal.ppat.1000219] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Accepted: 10/28/2008] [Indexed: 01/23/2023] Open
Abstract
Small interfering RNAs regulate gene expression in diverse biological processes, including heterochromatin formation and DNA elimination, developmental regulation, and cell differentiation. In the single-celled eukaryote Entamoeba histolytica, we have identified a population of small RNAs of 27 nt size that (i) have 5′-polyphosphate termini, (ii) map antisense to genes, and (iii) associate with an E. histolytica Piwi-related protein. Whole genome microarray expression analysis revealed that essentially all genes to which antisense small RNAs map were not expressed under trophozoite conditions, the parasite stage from which the small RNAs were cloned. However, a number of these genes were expressed in other E. histolytica strains with an inverse correlation between small RNA and gene expression level, suggesting that these small RNAs mediate silencing of the cognate gene. Overall, our results demonstrate that E. histolytica has an abundant 27 nt small RNA population, with features similar to secondary siRNAs from C. elegans, and which appear to regulate gene expression. These data indicate that a silencing pathway mediated by 5′-polyphosphate siRNAs extends to single-celled eukaryotic organisms. Regulation of gene expression can occur via multiple conserved pathways. One such mechanism is mediated by RNA molecules of about 21–24 nucleotides (called small RNAs), which can affect rates of RNA degradation or protein production. These small RNA molecules regulate diverse biological processes in a broad range of systems. The vast majority of the published literature about these molecules is from multi-cellular organisms. We have made a number of novel observations with respect to small RNA size, structure, and function in Entamoeba histolytica, a single-celled parasite and an important human pathogen. Our work has identified that E. histolytica has an abundant population of 27 nucleotide small RNAs, which have an unusual structure, indicating that they are generated by a relatively atypical mechanism. A substantial portion of these small RNAs are antisense to target genes and appear to silence them. These data establish a new paradigm for how gene expression is regulated in this organism. Furthermore, the identification of small RNAs with these structural characteristics dramatically broadens the evolutionary spectrum in which this phenomenon has been identified and indicates significant diversity and complexity of small RNAs and their functions in single-celled eukaryotes.
Collapse
|
34
|
Recent insights into Entamoeba development: identification of transcriptional networks associated with stage conversion. Int J Parasitol 2008; 39:41-7. [PMID: 18938171 DOI: 10.1016/j.ijpara.2008.09.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2008] [Accepted: 09/04/2008] [Indexed: 12/11/2022]
Abstract
Entamoeba histolytica is an important human pathogen and a leading parasitic cause of death globally. The parasite life cycle alternates between the trophozoite form, which is motile and causes invasive disease and the cyst stage, which is environmentally resistant and transmits infection. Understanding the triggers that initiate stage conversion is an important yet understudied area of investigation. Recent progress in dissecting the transcriptional networks that regulate E. histolytica development is outlined in this paper.
Collapse
|
35
|
Whangbo JS, Hunter CP. Environmental RNA interference. Trends Genet 2008; 24:297-305. [PMID: 18450316 DOI: 10.1016/j.tig.2008.03.007] [Citation(s) in RCA: 164] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2008] [Revised: 03/18/2008] [Accepted: 03/18/2008] [Indexed: 12/15/2022]
Abstract
The discovery of RNA interference (RNAi), the process of sequence-specific gene silencing initiated by double-stranded RNA (dsRNA), has broadened our understanding of gene regulation and has revolutionized methods for genetic analysis. A remarkable property of RNAi in the nematode Caenorhabditis elegans and in some other multicellular organisms is its systemic nature: silencing signals can cross cellular boundaries and spread between cells and tissues. Furthermore, C. elegans and some other organisms can also perform environmental RNAi: sequence-specific gene silencing in response to environmentally encountered dsRNA. This phenomenon has facilitated significant technological advances in diverse fields including functional genomics and agricultural pest control. Here, we describe the characterization and current understanding of environmental RNAi and discuss its potential applications.
Collapse
Affiliation(s)
- Jennifer S Whangbo
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | | |
Collapse
|
36
|
Bhattacharyya (Majumdar) S, Dey R, Majumder N, Bhattacharjee S, Majumdar S. A Novel Approach to Regulate Experimental Visceral Leishmaniasis in Murine Macrophages using CCR5 siRNA. Scand J Immunol 2008; 67:345-53. [DOI: 10.1111/j.1365-3083.2008.02076.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
37
|
Dastidar PG, Lohia A. Bipolar spindle frequency and genome content are inversely regulated by the activity of two N-type kinesins in Entamoeba histolytica. Cell Microbiol 2008; 10:1559-71. [PMID: 18363907 DOI: 10.1111/j.1462-5822.2008.01150.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Bipolar microtubular spindles are seen infrequently in Entamoeba histolytica trophozoites while monopolar or radial microtubular assemblies are common. Additionally, heterogeneity in nuclear DNA content and multi-nucleation is found in amoeba cells growing in axenic culture. Taken together these observations indicate that genome segregation is irregular in these cells. In order to identify proteins involved in regulating genome segregation, we have focused on studying E. histolytica homologues of kinesin motor proteins that are known to affect stability of bipolar mitotic spindles. We have demonstrated earlier that increased levels of the kinesin--Eh Klp5--led to increased frequency of bipolar spindles accompanied with a reduction in the heterogeneity of genome content, showing that bipolar spindle frequency was inversely linked to genome content in E. histolytica. In this study, we have investigated the role of E. histolytica kinesins (Eh KlpA1, 2-4) in regulating bipolar spindle frequency and genome content. While downregulation of Eh Klp3, 4 and A1 showed no effect, downregulation of Eh Klp2 led to increased frequency of bipolar spindles and homogenization of genome content, similar to the effect of increased expression of Eh Klp5. In addition to microtubules, Eh Klp2-4 associated with F-actin in the cytoplasm, suggesting that these kinesins are multi-functional.
Collapse
|
38
|
Entamoeba histolytica encodes unique formins, a subset of which regulates DNA content and cell division. Infect Immun 2008; 76:2368-78. [PMID: 18347041 DOI: 10.1128/iai.01449-07] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The formin family of proteins mediates dynamic changes in actin assembly in eukaryotes, and therefore it is important to understand the function of these proteins in Entamoeba histolytica, where actin forms the major cytoskeletal network. In this study we have identified the formin homologs encoded in the E. histolytica genome based on sequence analysis. Using multiple tools, we have analyzed the primary sequences of the eight E. histolytica formins and discovered three subsets: (i) E. histolytica formin-1 to -3 (Ehformin-1 to -3), (ii) Ehformin-4, and (iii) Ehformin-5 to -8. Two of these subsets (Ehformin-1 to -3 and Ehformin-4) showed significant sequence differences from their closest homologs, while Ehformin-5 to -8 were unique among all known formins. Since Ehformin-1 to -3 showed important sequence differences from Diaphanous-related formins (DRFs), we have studied the functions of Ehformin-1 and -2 in E. histolytica transformants. Like other DRFs, Ehformin-1 and -2 associated with F-actin in response to serum factors, in pseudopodia, in pinocytic and phagocytic vesicles, and at cell division sites. Ehformin-1 and -2 also localized with the microtubular assembly in the nucleus, indicating their involvement in genome segregation. While increased expression of Ehformin-1 and -2 did not affect phagocytosis or motility, it clearly showed an increase in the number of binucleated cells, the number of nuclei in multinucleated cells, and the average DNA content of each nucleus, suggesting that these proteins regulate both mitosis and cytokinesis in E. histolytica.
Collapse
|
39
|
Lohia A, Mukherjee C, Majumder S, Dastidar PG. Genome re-duplication and irregular segregation occur during the cell cycle of Entamoeba histolytica. Biosci Rep 2008; 27:373-84. [PMID: 17592766 DOI: 10.1007/s10540-007-9058-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Heterogeneity of genome content is commonly observed in axenic cultures of Entamoeba histolytica. Cells with multiple nuclei and nuclei with heterogenous genome contents suggest that regulatory mechanisms that ensure alternation of DNA synthesis and mitosis are absent in this organism. Therefore, several endo-reduplicative cycles may occur without mitosis. The data also shows that unlike other endo-reduplicating organisms, E.histolytica does not undergo a precise number of endo-reduplicative cycles. We propose that irregular endo-reduplication and genome partitioning lead to heterogeneity in the genome content of E.histolytica trophozoites in their proliferative phase. The goal of future studies should be aimed at understanding the mechanisms that are involved in (a) accumulation of multiple genome contents in a single nucleus; (b) genome segregation in nuclei that contain multiple genome contents and (c) maintenance of genome fidelity in E. histolytica.
Collapse
Affiliation(s)
- Anuradha Lohia
- Department of Biochemistry, Bose Institute, Kolkata, 700054, India.
| | | | | | | |
Collapse
|
40
|
Clark CG, Alsmark UCM, Tazreiter M, Saito-Nakano Y, Ali V, Marion S, Weber C, Mukherjee C, Bruchhaus I, Tannich E, Leippe M, Sicheritz-Ponten T, Foster PG, Samuelson J, Noël CJ, Hirt RP, Embley TM, Gilchrist CA, Mann BJ, Singh U, Ackers JP, Bhattacharya S, Bhattacharya A, Lohia A, Guillén N, Duchêne M, Nozaki T, Hall N. Structure and content of the Entamoeba histolytica genome. ADVANCES IN PARASITOLOGY 2008; 65:51-190. [PMID: 18063096 DOI: 10.1016/s0065-308x(07)65002-7] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The intestinal parasite Entamoeba histolytica is one of the first protists for which a draft genome sequence has been published. Although the genome is still incomplete, it is unlikely that many genes are missing from the list of those already identified. In this chapter we summarise the features of the genome as they are currently understood and provide previously unpublished analyses of many of the genes.
Collapse
Affiliation(s)
- C G Clark
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
MacFarlane RC, Singh U. Loss of dsRNA-based gene silencing in Entamoeba histolytica: implications for approaches to genetic analysis. Exp Parasitol 2008; 119:296-300. [PMID: 18346737 DOI: 10.1016/j.exppara.2008.02.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2007] [Revised: 01/29/2008] [Accepted: 02/01/2008] [Indexed: 11/29/2022]
Abstract
The ability to regulate gene expression in the protozoan parasite Entamoeba histolytica is critical in determining gene function. We previously published that expression of dsRNA specific to E. histolytica serine threonine isoleucine rich protein (EhSTIRP) resulted in reduction of gene expression [MacFarlane, R.C., Singh, U., 2007. Identification of an Entamoeba histolytica serine, threonine, isoleucine, rich protein with roles in adhesion and cytotoxicity. Eukaryotic Cell 6, 2139-2146]. However, after approximately one year of continuous drug selection, the expression of EhSTIRP reverted to wild-type levels. We confirmed that the parasites (i) contained the appropriate dsRNA plasmid, (ii) were not contaminated with other plasmids, (iii) the drug selectable marker was functional, and (iv) sequenced the dsRNA portion of the construct. This work suggests that in E. histolytica long term cultivation of parasites expressing dsRNA can lead to the loss of dsRNA based silencing through the selection of "RNAi" negative parasites. Thus, users of the dsRNA silencing approach should proceed with caution and regularly confirm gene down regulation. The development and use of constructs for inducible expression of dsRNA may help alleviate this potential problem.
Collapse
Affiliation(s)
- Ryan C MacFarlane
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305-5124, USA
| | | |
Collapse
|
42
|
Abed M, Ankri S. Progress and prospects of gene inactivation in Entamoeba histolytica. Exp Parasitol 2008; 118:151-5. [PMID: 17889851 DOI: 10.1016/j.exppara.2007.08.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Revised: 08/14/2007] [Accepted: 08/15/2007] [Indexed: 11/16/2022]
Abstract
Over the last few years, numerous methods have been exploited in the attempt to study Entamoeba histolytica gene functions. Yet several features of E. histolytica, like their variable DNA content and complex ploidity have made it difficult to perform classical genetic studies such as homologous recombination. As a result, the methods currently in use target genes at the protein or RNA level. This review summarizes the experimental approaches that have been used to date and it provides an overview of the limitations and contributions of these methods in our understanding of E. histolytica's gene functions and biology.
Collapse
Affiliation(s)
- Mona Abed
- Department of Molecular Microbiology, Rappaport Faculty of Medicine and Research Institute, Technion--Israel Institute of Technology, 1 Efron Street, Haifa, 31096, Israel
| | | |
Collapse
|
43
|
Solis CF, Guillén N. Silencing genes by RNA interference in the protozoan parasite Entamoeba histolytica. Methods Mol Biol 2008; 442:113-28. [PMID: 18369782 DOI: 10.1007/978-1-59745-191-8_9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Experimental procedures using the RNA interference (RNAi) approach have recently emerged as a powerful tool for gene silencing in eukaryotic microbes for which gene replacement techniques have not yet been developed. Our group has recently explored RNAi to knock down gene-specific expression in the protozoan parasite Entamoeba histolytica, through delivery of small interfering RNA (siRNA) oligonucleotides by the soaking approach. Standardized conditions for the soaking of E. histolytica trophozoites with siRNAs result in highly specific and significant silencing of parasite cognate genes. Real-time PCR analysis indicates that a 16-hour treatment with siRNAs usually results in half-extinction of target messenger RNA. Furthermore, Western blot analysis of trophozoite crude extracts with the use of specific antibodies shows a similar reduction of cognate protein levels after siRNA treatment.
Collapse
Affiliation(s)
- Carlos F Solis
- Unité de Biologie Cellulaire du Parasitisme, Institut Pasteur, Paris, France
| | | |
Collapse
|
44
|
Militello KT, Refour P, Comeaux CA, Duraisingh MT. Antisense RNA and RNAi in protozoan parasites: working hard or hardly working? Mol Biochem Parasitol 2007; 157:117-26. [PMID: 18053590 DOI: 10.1016/j.molbiopara.2007.10.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Revised: 10/11/2007] [Accepted: 10/12/2007] [Indexed: 10/22/2022]
Abstract
The complex life cycles of many protozoan parasites require the ability to respond to environmental and developmental cues through regulated gene expression. Traditionally, parasitologists have investigated these mechanisms by identifying and characterizing proteins that are necessary for the regulated expression of the genetic material. Although often successful, it is clear that protein-mediated gene regulation is only part of a complex story in which RNA itself is endowed with regulatory functions. Herein, we review both the known and potential regulatory roles of two types of RNA pathways within protozoan parasites: the RNA interference pathway and natural antisense transcripts. A better understanding of the native role of these pathways will not only enhance our understanding of the biology of these organisms but also aid in the development of more robust tools for reverse genetic analysis in this post-genomic era.
Collapse
Affiliation(s)
- Kevin T Militello
- Department of Biology, State University of New York at Geneseo, Geneseo, NY, USA
| | | | | | | |
Collapse
|
45
|
Santi-Rocca J, Weber C, Guigon G, Sismeiro O, Coppée JY, Guillén N. The lysine- and glutamic acid-rich protein KERP1 plays a role in Entamoeba histolytica liver abscess pathogenesis. Cell Microbiol 2007; 10:202-17. [PMID: 17711481 DOI: 10.1111/j.1462-5822.2007.01030.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The parasite Entamoeba histolytica colonizes the large bowel where it may persist as an asymptomatic luminal gut infection, which changes to virulence. Parasite invasion of the intestine leads to dysentery and spreads to the liver, where amoebae form abscesses. We took advantage of changes in virulence that occurs after long-term in vitro culture of E. histolytica strains. Using microarrays, we concluded that virulence correlates with upregulation of key genes involved in stress response, including molecular chaperones, ssp1 and peroxiredoxin; as well as the induction of unknown genes encoding lysine-rich proteins. Seven of these were retained with respect to their lysine content higher than 25%. Among them, we found KERP1, formerly identified as associated to parasite surface and involved in the parasite adherence to host cells. Experimentally induced liver abscesses, using molecular beacons and protein analysis, allowed us to draw a parallel between the intricate upregulation of kerp1 gene expression during abscess development and the increased abundance of KERP1 in virulent trophozoites. Following its characterization as a marker for the progression of infection, KERP1 was also seen to be a virulence marker as trophozoites affected in kerp1 expression by an antisense strategy were unable to form liver abscesses.
Collapse
Affiliation(s)
- Julien Santi-Rocca
- Institut Pasteur, Unité Biologie Cellulaire du Parasitisme, Paris, F-75015, France, and INSERM U786, Paris, F-75015, France
| | | | | | | | | | | |
Collapse
|
46
|
Replacement of the essential Dictyostelium Arp2 gene by its Entamoeba homologue using parasexual genetics. BMC Genet 2007; 8:28. [PMID: 17553170 PMCID: PMC1904233 DOI: 10.1186/1471-2156-8-28] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2007] [Accepted: 06/06/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cell motility is an essential feature of the pathogenesis and morbidity of amoebiasis caused by Entamoeba histolytica. As motility depends on cytoskeletal organisation and regulation, a study of the molecular components involved is key to a better understanding of amoebic pathogenesis. However, little is known about the physiological roles, interactions and regulation of the proteins of the Entamoeba cytoskeleton. RESULTS We have established a genetic strategy that uses parasexual genetics to allow essential Dictyostelium discoideum genes to be manipulated and replaced with modified or tagged homologues. Our results show that actin related protein 2 (Arp2) is essential for survival, but that the Dictyostelium protein can be complemented by E. histolytica Arp2, despite the presence of an insertion of 16 amino acids in an otherwise highly conserved protein. Replacement of endogenous Arp2 with myc-tagged Entamoeba or Dictyostelium Arp2 has no obvious effects on growth and the protein incorporates effectively into the Arp2/3 complex. CONCLUSION We have established an effective two-step method for replacing genes that are required for survival. Our protocol will allow such genes to be studied far more easily, and also allows an unambiguous demonstration that particular genes are truly essential. In addition, cells in which the Dictyostelium Arp2 has been replaced by the Entamoeba protein are potential targets for drug screens.
Collapse
|
47
|
Meissner M, Agop-Nersesian C, Sullivan WJ. Molecular tools for analysis of gene function in parasitic microorganisms. Appl Microbiol Biotechnol 2007; 75:963-75. [PMID: 17401559 DOI: 10.1007/s00253-007-0946-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2007] [Revised: 03/12/2007] [Accepted: 03/12/2007] [Indexed: 01/01/2023]
Abstract
With the completion of several genome sequences for parasitic protozoa, research in molecular parasitology entered the "post-genomic" era. Accompanied by global transcriptome and proteome analysis, huge datasets have been generated that have added many novel candidates to the list of drug and vaccine targets. The challenge is now to validate these factors and to bring science back to the bench to perform a detailed characterization. In some parasites, like Trypanosoma brucei, high-throughput genetic screens have been established using RNA interference [for a detailed review, see Motyka and Englund (2004)]. In most protozoan parasites, however, more time-consuming approaches have to be employed to identify and characterize the function of promising candidates in detail. This review aims to summarize the status of molecular genetic tools available for a variety of protozoan pathogens and discuss how they can be implemented to advance our understanding of parasite biology.
Collapse
Affiliation(s)
- Markus Meissner
- Hygieneinstitut, Abteilung Parasitologie, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany.
| | | | | |
Collapse
|
48
|
Dastidar PG, Majumder S, Lohia A. Eh Klp5 is a divergent member of the kinesin 5 family that regulates genome content and microtubular assembly in Entamoeba histolytica. Cell Microbiol 2007; 9:316-28. [PMID: 16925786 DOI: 10.1111/j.1462-5822.2006.00788.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Earlier studies have established two unusual features in the cell division cycle of Entamoeba histolytica. First, microtubules form a radial assembly instead of a bipolar mitotic spindle, and second, the genome content of E. histolytica cells varied from 1x to 6x or more. In this study, Eh Klp5 was identified as a divergent member of the BimC kinesin family that is known to regulate formation and stabilization of the mitotic spindle in other eukaryotes. In contrast to earlier studies, we show here that bipolar microtubular spindles were formed in E. histolytica but were visible only in 8-12% of the cells after treatment with taxol. The number of bipolar spindles was significantly increased in Eh Klp5 stable transformants (20-25%) whereas Eh Klp5 double-stranded RNA (dsRNA) transformants did not show any spindles (< 1%). The genome content of Eh Klp5 stable transformants was regulated between 1x and 2x unlike control cells. Binucleated cells accumulated in Eh Klp5 dsRNA transformants and after inhibition of Eh Klp5 with small molecule inhibitors in control cells, suggesting that cytokinesis was delayed in the absence of Eh Klp5. Taken together, our results indicate that Eh Klp5 regulates microtubular assembly, genome content and cell division in E. histolytica. Additionally, Eh Klp5 showed alterations in its drug-binding site compared with its human homologue, Hs Eg5 and this was reflected in its reduced sensitivity to Eg5 inhibitors - monastrol and HR22C16 analogues.
Collapse
|
49
|
Rivière C, Marion S, Guillén N, Bacri JC, Gazeau F, Wilhelm C. Signaling through the phosphatidylinositol 3-kinase regulates mechanotaxis induced by local low magnetic forces in Entamoeba histolytica. J Biomech 2007; 40:64-77. [PMID: 16406381 DOI: 10.1016/j.jbiomech.2005.11.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2005] [Accepted: 11/23/2005] [Indexed: 12/22/2022]
Abstract
In micro-organisms, as well as in metazoan cells, cellular polarization and directed migration are finely regulated by external stimuli, including mechanical stresses. The mechanisms sustaining the transduction of such external stresses into intracellular biochemical signals remain mainly unknown. Using an external magnetic tip, we generated a magnetic field gradient that allows migration analysis of cells submitted to local low-intensity magnetic forces (50 pN). We applied our system to the amoeba Entamoeba histolytica. Indeed, motility and chemotaxis are key activities that allow this parasite to invade and destroy the human tissues during amoebiasis. The magnetic force was applied either inside the cytoplasm or externally at the rear pole of the amoeba. We observed that the application of an intracellular force did not affect cell polarization and migration, whereas the application of the force at the rear pole of the cell induced a persistent polarization and strongly directional motion, almost directly opposed to the magnetic force. This phenomenon was completely abolished when phosphatidylinositol 3-kinase activity was inhibited by wortmanin. This result demonstrated that the applied mechanical stimulus was transduced and amplified into an intracellular biochemical signal, a process that allows such low-intensity force to strongly modify the migration behavior of the cell.
Collapse
Affiliation(s)
- C Rivière
- Pôle Matière et Systèmes Complexes, Université Paris 7, Denis Diderot, CNRS UMR7057, 140, rue de Lourmel, 75015 Paris, France
| | | | | | | | | | | |
Collapse
|
50
|
De S, Pal D, Ghosh SK. Entamoeba histolytica: Computational identification of putative microRNA candidates. Exp Parasitol 2006; 113:239-43. [PMID: 16515787 DOI: 10.1016/j.exppara.2006.01.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2005] [Revised: 01/19/2006] [Accepted: 01/20/2006] [Indexed: 11/23/2022]
Abstract
MicroRNAs are an abundant class of approximately 20-24-nucleotide noncoding RNAs that control the expression of several genes at the post-transcriptional level, regulating several important biochemical pathways. MicroRNAs have been identified in many vertebrates including humans, and also in flies, nematodes, plants, and viruses. In the present work we have identified seventeen putative candidate microRNAs in the pathogenic parasite Entamoeba histolytica using a bioinformatic approach. Putative microRNA identification in E. histolytica may act as a starting reference for cloning and characterization of miRNAs in Entamoeba genome.
Collapse
Affiliation(s)
- Subhajyoti De
- Department of Biotechnology, Indian Institute of Technology-Kharagpur, Kharagpur 721302, India
| | | | | |
Collapse
|