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Welter BH, Sehorn MG, Temesvari LA. Flow cytometric characterization of encystation in Entamoeba invadens. Mol Biochem Parasitol 2017; 218:23-27. [PMID: 29037797 DOI: 10.1016/j.molbiopara.2017.10.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 10/12/2017] [Accepted: 10/13/2017] [Indexed: 10/18/2022]
Abstract
Entamoeba histolytica causes dysentery and liver abscess mostly in countries that lack proper sanitation. Infection is acquired by ingestion of the cyst form in contaminated food or water. E. histolytica does not encyst in vitro; thus, E. invadens, a reptilian parasite that encysts in vitro, has been used as a surrogate. Cysts are small and possess chitin-rich walls. These are characteristics that may be exploited by flow cytometry. We stained encysting E. invadens cells with a fluorescent chitin stain, and analyzed fluorescence and forward scatter by flow cytometry. We demonstrate that flow cytometry can be used to track differentiation, reveal unique cell populations, and evaluate encystation inhibitors.
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Affiliation(s)
- Brenda H Welter
- Department of Biological Sciences, Clemson University, Clemson, SC, 29634, USA; Eukaryotic Pathogens Innovation Center (EPIC), Clemson University, Clemson, SC, 29634, USA
| | - Michael G Sehorn
- Department of Genetics and Biochemistry, Clemson University, Clemson, SC, 29634, USA; Eukaryotic Pathogens Innovation Center (EPIC), Clemson University, Clemson, SC, 29634, USA
| | - Lesly A Temesvari
- Department of Biological Sciences, Clemson University, Clemson, SC, 29634, USA; Eukaryotic Pathogens Innovation Center (EPIC), Clemson University, Clemson, SC, 29634, USA.
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52
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Herman E, Siegesmund MA, Bottery MJ, van Aerle R, Shather MM, Caler E, Dacks JB, van der Giezen M. Membrane Trafficking Modulation during Entamoeba Encystation. Sci Rep 2017; 7:12854. [PMID: 28993644 PMCID: PMC5634486 DOI: 10.1038/s41598-017-12875-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 09/11/2017] [Indexed: 12/15/2022] Open
Abstract
Entamoeba histolytica is an intestinal parasite that infects 50-100 million people and causes up to 55,000 deaths annually. The transmissive form of E. histolytica is the cyst, with a single infected individual passing up to 45 million cysts per day, making cyst production an attractive target for infection control. Lectins and chitin are secreted to form the cyst wall, although little is known about the underlying membrane trafficking processes supporting encystation. As E. histolytica does not readily form cysts in vitro, we assessed membrane trafficking gene expression during encystation in the closely related model Entamoeba invadens. Genes involved in secretion are up-regulated during cyst formation, as are some trans-Golgi network-to-endosome trafficking genes. Furthermore, endocytic and general trafficking genes are up-regulated in the mature cyst, potentially preserved as mRNA in preparation for excystation. Two divergent dynamin-related proteins found in Entamoeba are predominantly expressed during cyst formation. Phylogenetic analyses indicate that they are paralogous to, but quite distinct from, classical dynamins found in human, suggesting that they may be potential drug targets to block encystation. The membrane-trafficking machinery is clearly regulated during encystation, providing an additional facet to understanding this crucial parasitic process.
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Affiliation(s)
- Emily Herman
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, T6G 2H7, Edmonton, Alberta, Canada
| | | | - Michael J Bottery
- Department of Biology, University of York, Heslington, York, YO10 5DD, UK
| | - Ronny van Aerle
- Biosciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
- Centre for Environment, Fisheries, and Aquaculture Science (Cefas), Barrack Road, The Nothe, Weymouth, Dorset, DT4 8UB, UK
| | | | - Elisabet Caler
- J. Craig Venter Institute, 9714 Medical Center Drive, Rockville, MD, 20850, USA
- National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), 6701, Rockledge Drive, Room 9144, Bethesda, MD, 20892-7950, USA
| | - Joel B Dacks
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, T6G 2H7, Edmonton, Alberta, Canada.
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Kelso AA, Waldvogel SM, Luthman AJ, Sehorn MG. Homologous Recombination in Protozoan Parasites and Recombinase Inhibitors. Front Microbiol 2017; 8:1716. [PMID: 28936205 PMCID: PMC5594099 DOI: 10.3389/fmicb.2017.01716] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Accepted: 08/24/2017] [Indexed: 01/30/2023] Open
Affiliation(s)
- Andrew A. Kelso
- Department of Genetics and Biochemistry, Clemson University, ClemsonSC, United States
- Eukaryotic Pathogens Innovation Center, Clemson University, ClemsonSC, United States
| | - Sarah M. Waldvogel
- Department of Genetics and Biochemistry, Clemson University, ClemsonSC, United States
| | - Adam J. Luthman
- Department of Genetics and Biochemistry, Clemson University, ClemsonSC, United States
| | - Michael G. Sehorn
- Department of Genetics and Biochemistry, Clemson University, ClemsonSC, United States
- Eukaryotic Pathogens Innovation Center, Clemson University, ClemsonSC, United States
- Center for Optical Materials Science and Engineering Technologies, Clemson University, ClemsonSC, United States
- Clemson University School of Health Research, Clemson University, ClemsonSC, United States
- *Correspondence: Michael G. Sehorn,
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Rougeron V, De Meeûs T, Bañuls AL. Reproduction in Leishmania: A focus on genetic exchange. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2017; 50:128-132. [PMID: 27769896 DOI: 10.1016/j.meegid.2016.10.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 10/17/2016] [Accepted: 10/18/2016] [Indexed: 11/26/2022]
Abstract
One key process of the life cycle of pathogens is their mode of reproduction. Indeed, this fundamental biological process conditions the multiplication and the transmission of genes and thus the propagation of diseases in the environment. Reproductive strategies of protozoan parasites have been a subject of debate for many years, principally due to the difficulty in making direct observations of sexual reproduction (i.e. genetic recombination). Traditionally, these parasites were considered as characterized by a preeminent clonal structure. Nevertheless, with the development of elaborate culture experiments, population genetics and evolutionary and population genomics, several studies suggested that most of these pathogens were also characterized by constitutive genetic recombination events. In this opinion, we focused on Leishmania parasites, pathogens responsible of leishmaniases, a major public health issue. We first discuss the evolutionary advantages of a mixed mating reproductive strategy, then we review the evidence of genetic exchange, and finally we detail available tools to detect naturally occurring genetic recombination in Leishmania parasites and more generally in protozoan parasites.
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Affiliation(s)
- V Rougeron
- MIVEGEC (Laboratoire Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle), UMR CNRS 5290-IRD 224-Université de Montpellier, Montpellier, France.
| | - T De Meeûs
- Institut de Recherche pour le Développement (IRD), UMR 177 INTERTRYP IRD-CIRAD, TA A-17/G, Campus International de Baillarguet, 34398 Montpellier Cedex 5, France
| | - A-L Bañuls
- MIVEGEC (Laboratoire Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle), UMR CNRS 5290-IRD 224-Université de Montpellier, Montpellier, France
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Hendrick HM, Welter BH, Hapstack MA, Sykes SE, Sullivan WJ, Temesvari LA. Phosphorylation of Eukaryotic Initiation Factor-2α during Stress and Encystation in Entamoeba Species. PLoS Pathog 2016; 12:e1006085. [PMID: 27930733 PMCID: PMC5179133 DOI: 10.1371/journal.ppat.1006085] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 12/22/2016] [Accepted: 11/23/2016] [Indexed: 12/21/2022] Open
Abstract
Entamoeba histolytica is an enteric pathogen responsible for amoebic dysentery and liver abscess. It alternates between the host-restricted trophozoite form and the infective environmentally-stable cyst stage. Throughout its lifecycle E. histolytica experiences stress, in part, from host immune pressure. Conversion to cysts is presumed to be a stress-response. In other systems, stress induces phosphorylation of a serine residue on eukaryotic translation initiation factor-2α (eIF2α). This inhibits eIF2α activity resulting in a general decline in protein synthesis. Genomic data reveal that E. histolytica possesses eIF2α (EheIF2α) with a conserved phosphorylatable serine at position 59 (Ser59). Thus, this pathogen may have the machinery for stress-induced translational control. To test this, we exposed cells to different stress conditions and measured the level of total and phospho-EheIF2α. Long-term serum starvation, long-term heat shock, and oxidative stress induced an increase in the level of phospho-EheIF2α, while short-term serum starvation, short-term heat shock, or glucose deprivation did not. Long-term serum starvation also caused a decrease in polyribosome abundance, which is in accordance with the observation that this condition induces phosphorylation of EheIF2α. We generated transgenic cells that overexpress wildtype EheIF2α, a non-phosphorylatable variant of eIF2α in which Ser59 was mutated to alanine (EheIF2α-S59A), or a phosphomimetic variant of eIF2α in which Ser59 was mutated to aspartic acid (EheIF2α-S59D). Consistent with the known functions of eIF2α, cells expressing wildtype or EheIF2α-S59D exhibited increased or decreased translation, respectively. Surprisingly, cells expressing EheIF2α-S59A also exhibited reduced translation. Cells expressing EheIF2α-S59D were more resistant to long-term serum starvation underscoring the significance of EheIF2α phosphorylation in managing stress. Finally, phospho-eIF2α accumulated during encystation in E. invadens, a model encystation system. Together, these data demonstrate that the eIF2α-dependent stress response system is operational in Entamoeba species. Entamoeba histolytica is the causative agent of amoebic dysentery and liver abscess and is prevalent in underdeveloped countries that lack proper sanitation. Infection is acquired by ingestion of the cyst form in contaminated food or water. During infection, the parasite experiences stress including demanding growth conditions and host immune pressure. Conversion to the infective cyst may be induced by such stress. In other organisms, stress causes a decrease in protein biosynthesis by inducing phosphorylation of eIF2α, which participates in translation initiation. We exposed E. histolytica to six different stress conditions and observed that some of these conditions (long-term serum starvation, long-term heat shock, and oxidative stress) induced an increase in the level of phospho-eIF2α. Long-term serum starvation was also accompanied by a decrease in mRNA translation. A cell line expressing a mutant version of eIF2α that behaves as a phosphomimetic exhibited decreased translation and increased survival during long-term serum starvation. Finally, phospho-eIF2α accumulated in cysts of E. invadens, a reptilian pathogen that readily encysts in vitro. Together, these data demonstrate that the eIF2α-dependent stress response system is operational in Entamoeba and may regulate encystation.
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Affiliation(s)
- Holland M. Hendrick
- Department of Biological Sciences, Clemson University Clemson, South Carolina, United States of America
- Eukaryotic Pathogens Innovation Center (EPIC) Clemson University Clemson, South Carolina, United States of America
| | - Brenda H. Welter
- Department of Biological Sciences, Clemson University Clemson, South Carolina, United States of America
- Eukaryotic Pathogens Innovation Center (EPIC) Clemson University Clemson, South Carolina, United States of America
| | - Matthew A. Hapstack
- Department of Biological Sciences, Clemson University Clemson, South Carolina, United States of America
- Eukaryotic Pathogens Innovation Center (EPIC) Clemson University Clemson, South Carolina, United States of America
| | - Steven E. Sykes
- Department of Biological Sciences, Clemson University Clemson, South Carolina, United States of America
- Eukaryotic Pathogens Innovation Center (EPIC) Clemson University Clemson, South Carolina, United States of America
| | - William J. Sullivan
- Department of Pharmacology and Toxicology Indiana University School of Medicine Indianaplois, IN United States of America
- Department of Microbiology and Immunology Indiana University School of Medicine Indianapolis, IN United States of America
| | - Lesly A. Temesvari
- Department of Biological Sciences, Clemson University Clemson, South Carolina, United States of America
- Eukaryotic Pathogens Innovation Center (EPIC) Clemson University Clemson, South Carolina, United States of America
- * E-mail:
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56
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Abstract
Amebiasis is caused by Entamoeba histolytica infection and can produce a broad range of clinical signs, from asymptomatic cases to patients with obvious symptoms. The current epidemiological and clinical statuses of amebiasis make it a serious public health problem worldwide. The Entamoeba life cycle consists of the trophozoite, the causative agent for amebiasis, and the cyst, the form responsible for transmission. These two stages are connected by "encystation" and "excystation." Hence, developing novel strategies to control encystation and excystation will potentially lead to new measures to block the transmission of amebiasis by interrupting the life cycle of the causative agent. Here, we highlight studies investigating encystation using inhibitory chemicals and categorize them based on the molecules inhibited. We also present a perspective on new strategies to prevent the transmission of amebiasis.
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Affiliation(s)
- Fumika Mi-ichi
- Division of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, Saga, Japan
- * E-mail:
| | - Hiroki Yoshida
- Division of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, Saga, Japan
| | - Shinjiro Hamano
- Department of Parasitology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan
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57
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Sarjapuram N, Mekala N, Singh M, Tatu U. The Potential of Lactobacillus casei and Entercoccus faecium Combination as a Preventive Probiotic Against Entamoeba. Probiotics Antimicrob Proteins 2016; 9:142-149. [DOI: 10.1007/s12602-016-9232-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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58
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Abstract
The outcome of an Entamoeba histolytica infection is variable and the contribution of genetic diversity within E. histolytica to human disease is not fully understood. The information provided by the whole genome sequence of the E. histolytica reference laboratory strain (HM-1:IMSS) and thirteen additional laboratory strains have been made publically available. In this review theories on the source of the unexpected level of structural diversity found in E. histolytica will be discussed.
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Affiliation(s)
- Carol A Gilchrist
- Department of Medicine, School of Medicine, University of Virginia, Charlottesville, Virginia, United States of America
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59
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Espinosa A, Paz-Y-Miño-C G, Hackey M, Rutherford S. Entamoeba Clone-Recognition Experiments: Morphometrics, Aggregative Behavior, and Cell-Signaling Characterization. J Eukaryot Microbiol 2016; 63:384-93. [PMID: 26990199 DOI: 10.1111/jeu.12313] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Revised: 03/09/2016] [Accepted: 03/09/2016] [Indexed: 11/30/2022]
Abstract
Studies on clone- and kin-discrimination in protists have proliferated during the past decade. We report clone-recognition experiments in seven Entamoeba lineages (E. invadens IP-1, E. invadens VK-1:NS, E. terrapinae, E. moshkovskii Laredo, E. moshkovskii Snake, E. histolytica HM-1:IMSS and E. dispar). First, we characterized morphometrically each clone (length, width, and cell-surface area) and documented how they differed statistically from one another (as per single-variable or canonical-discriminant analyses). Second, we demonstrated that amebas themselves could discriminate self (clone) from different (themselves vs. other clones). In mix-cell-line cultures between closely-related (E. invadens IP-1 vs. E. invadens VK-1:NS) or distant-phylogenetic clones (E. terrapinae vs. E. moshkovskii Laredo), amebas consistently aggregated with same-clone members. Third, we identified six putative cell-signals secreted by the amebas (RasGap/Ankyrin, coronin-WD40, actin, protein kinases, heat shock 70, and ubiquitin) and which known functions in Entamoeba spp. included: cell proliferation, cell adhesion, cell movement, and stress-induced encystation. To our knowledge, this is the first multi-clone characterization of Entamoeba spp. morphometrics, aggregative behavior, and cell-signaling secretion in the context of clone-recognition. Protists allow us to study cell-cell recognition from ecological and evolutionary perspectives. Modern protistan lineages can be central to studies about the origins and evolution of multicellularity.
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Affiliation(s)
- Avelina Espinosa
- Department of Biology, Roger Williams University, Bristol, Rhode Island, USA.,New England Center for the Public Understanding of Science, Roger Williams University, Bristol, Rhode Island, USA
| | - Guillermo Paz-Y-Miño-C
- New England Center for the Public Understanding of Science, Roger Williams University, Bristol, Rhode Island, USA
| | - Meagan Hackey
- Department of Biology, Roger Williams University, Bristol, Rhode Island, USA
| | - Scott Rutherford
- Department of Environmental Science, Roger Williams University, Bristol, Rhode Island, USA
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60
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Einarsson E, Troell K, Hoeppner MP, Grabherr M, Ribacke U, Svärd SG. Coordinated Changes in Gene Expression Throughout Encystation of Giardia intestinalis. PLoS Negl Trop Dis 2016; 10:e0004571. [PMID: 27015092 PMCID: PMC4807828 DOI: 10.1371/journal.pntd.0004571] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 03/03/2016] [Indexed: 12/29/2022] Open
Abstract
Differentiation into infectious cysts through the process of encystation is crucial for transmission and survival of the intestinal protozoan parasite Giardia intestinalis. Hitherto the majority of studies have focused on the early events, leaving late encystation poorly defined. In order to further study encystation, focusing on the later events, we developed a new encystation protocol that generates a higher yield of mature cysts compared to standard methods. Transcriptome changes during the entire differentiation from trophozoites to cysts were thereafter studied using RNA sequencing (RNA-seq). A high level of periodicity was observed for up- and down-regulated genes, both at the level of the entire transcriptome and putative regulators. This suggests the trajectory of differentiation to be coordinated through developmentally linked gene regulatory activities. Our study identifies a core of 13 genes that are consistently up-regulated during initial encystation. Of these, two constitute previously uncharacterized proteins that we were able to localize to a new type of encystation-specific vesicles. Interestingly, the largest transcriptional changes were seen in the late phase of encystation with the majority of the highly up-regulated genes encoding hypothetical proteins. Several of these were epitope-tagged and localized to further characterize these previously unknown genetic components of encystation and possibly excystation. Finally, we also detected a switch of variant specific surface proteins (VSPs) in the late phase of encystation. This occurred at the same time as nuclear division and DNA replication, suggesting a potential link between the processes. The intestinal protozoan parasite Giardia intestinalis and many other medically important protozoan parasites must encyst and form infective cysts in order to transmit to new hosts. Encystation efficiency is in that way connected to efficiency of transmission. We have developed new in vitro differentiation protocols and made the first RNA-seq based gene expression study of the complete Giardia encystation process. Our data provides a road map of Giardia encystation and a starting point from where it is possible to further explore important processes occurring during encystation. Information about this vital process for survival in the environment of this and other cyst forming parasites can be used in the development of new types of interventions.
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Affiliation(s)
- Elin Einarsson
- Department of Cell and Molecular Biology, BMC, Uppsala University, Uppsala, Sweden
| | - Karin Troell
- Department of Cell and Molecular Biology, BMC, Uppsala University, Uppsala, Sweden
- Department of Microbiology, National Veterinary Institute, Uppsala, Sweden
| | - Marc P. Hoeppner
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
- Christian-Albrechts-University of Kiel, Institute of Clinical Molecular Biology, Kiel, Germany
| | - Manfred Grabherr
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Ulf Ribacke
- Department of Cell and Molecular Biology, BMC, Uppsala University, Uppsala, Sweden
| | - Staffan G. Svärd
- Department of Cell and Molecular Biology, BMC, Uppsala University, Uppsala, Sweden
- * E-mail:
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61
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Development of RNA Interference Trigger-Mediated Gene Silencing in Entamoeba invadens. Infect Immun 2016; 84:964-975. [PMID: 26787723 DOI: 10.1128/iai.01161-15] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 01/14/2016] [Indexed: 01/08/2023] Open
Abstract
Entamoeba histolytica, a protozoan parasite, is an important human pathogen and a leading parasitic cause of death. The organism has two life cycle stages, trophozoites, which are responsible for tissue invasion, and cysts, which are involved in pathogen transmission. Entamoeba invadens is the model system to study Entamoeba developmental biology, as high-grade regulated encystation and excystation are readily achievable. However, the lack of gene-silencing tools in E. invadens has limited the molecular studies that can be performed. Using the endogenous RNA interference (RNAi) pathway in Entamoeba, we developed an RNAi-based trigger gene-silencing approach inE. invadens We demonstrate that a gene's coding region that has abundant antisense small RNAs (sRNAs) can trigger silencing of a gene that is fused to it. The trigger fusion leads to the generation of abundant antisense sRNAs that map to the target gene, with silencing occurring independently of trigger location at the 5' or 3' end of a gene. Gene silencing is stably maintained during development, including encystation and excystation. We have used this approach to successfully silence two E. invadens genes: a putative rhomboid protease gene and a SHAQKY family Myb gene. The Myb gene is upregulated during oxidative stress and development, and its downregulation led, as predicted, to decreased viability under oxidative stress and decreased cyst formation. Thus, the RNAi trigger silencing method can be used to successfully investigate the molecular functions of genes inE. invadens Dissection of the molecular basis of Entamoeba stage conversion is now possible, representing an important technical advance for the system.
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62
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Hasanuzzaman AFM, Robledo D, Gómez-Tato A, Alvarez-Dios JA, Harrison PW, Cao A, Fernández-Boo S, Villalba A, Pardo BG, Martínez P. De novo transcriptome assembly of Perkinsus olseni trophozoite stimulated in vitro with Manila clam (Ruditapes philippinarum) plasma. J Invertebr Pathol 2016; 135:22-33. [DOI: 10.1016/j.jip.2016.01.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 01/18/2016] [Accepted: 01/24/2016] [Indexed: 12/13/2022]
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63
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Bloomfield G. Atypical ploidy cycles, Spo11, and the evolution of meiosis. Semin Cell Dev Biol 2016; 54:158-64. [PMID: 26811992 DOI: 10.1016/j.semcdb.2016.01.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 01/20/2016] [Indexed: 12/14/2022]
Abstract
The Spo11 protein induces DNA double strand breaks before the first division of meiosis, enabling the formation of the chiasmata that physically link homologous chromosomes as they align. Spo11 is an ancient and well conserved protein, related in sequence and structure to a DNA topoisomerase subunit found in Archaea as well as a subset of eukaryotes. However the origins of its meiotic function are unclear. This review examines some apparent exceptions to the rule that Spo11 activity is specific to, and required for meiosis. Spo11 appears to function in the context of unusual forms of ploidy reduction in some protists and fungi. One lineage of amoebae, the dictyostelids, is thought to undergo meiosis during its sexual cycle despite having lost Spo11 entirely. Further experimental characterisation of these and other non-canonical ploidy cycling mechanisms may cast light of the evolution of meiosis.
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Affiliation(s)
- Gareth Bloomfield
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, CB2 0QH, United Kingdom.
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64
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Singh M, Sharma S, Bhattacharya A, Tatu U. Heat Shock Protein 90 regulates encystation in Entamoeba. Front Microbiol 2015; 6:1125. [PMID: 26528271 PMCID: PMC4602144 DOI: 10.3389/fmicb.2015.01125] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 09/28/2015] [Indexed: 11/18/2022] Open
Abstract
Enteric protozoan Entamoeba histolytica is a major cause of debilitating diarrheal infection worldwide with high morbidity and mortality. Even though the clinical burden of this parasite is very high, this infection is categorized as a neglected disease. Parasite is transmitted through feco-oral route and exhibit two distinct stages namely – trophozoites and cysts. Mechanism and regulation of encystation is not clearly understood. Previous studies have established the role of Heat shock protein 90 (Hsp90) in regulating stage transition in various protozoan parasites like Giardia, Plasmodium, Leishmania, and Toxoplasma. Our study for the first time reports that Hsp90 plays a crucial role in life cycle of Entamoeba as well. We identify Hsp90 to be a negative regulator of encystation in Entamoeba. We also show that Hsp90 inhibition interferes with the process of phagocytosis in Entamoeba. Overall, we show that Hsp90 plays an important role in virulence and transmission of Entamoeba.
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Affiliation(s)
- Meetali Singh
- Department of Biochemistry, Indian Institute of Science Bangalore, India
| | - Shalini Sharma
- School of Life Sciences, Jawaharlal Nehru University New Delhi, India
| | - Alok Bhattacharya
- School of Life Sciences, Jawaharlal Nehru University New Delhi, India
| | - Utpal Tatu
- Department of Biochemistry, Indian Institute of Science Bangalore, India
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65
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Kelso AA, Say AF, Sharma D, Ledford LL, Turchick A, Saski CA, King AV, Attaway CC, Temesvari LA, Sehorn MG. Entamoeba histolytica Dmc1 Catalyzes Homologous DNA Pairing and Strand Exchange That Is Stimulated by Calcium and Hop2-Mnd1. PLoS One 2015; 10:e0139399. [PMID: 26422142 PMCID: PMC4589404 DOI: 10.1371/journal.pone.0139399] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 09/12/2015] [Indexed: 01/03/2023] Open
Abstract
Meiosis depends on homologous recombination (HR) in most sexually reproducing organisms. Efficient meiotic HR requires the activity of the meiosis-specific recombinase, Dmc1. Previous work shows Dmc1 is expressed in Entamoeba histolytica, a eukaryotic parasite responsible for amoebiasis throughout the world, suggesting this organism undergoes meiosis. Here, we demonstrate Dmc1 protein is expressed in E. histolytica. We show that purified ehDmc1 forms presynaptic filaments and catalyzes ATP-dependent homologous DNA pairing and DNA strand exchange over at least several thousand base pairs. The DNA pairing and strand exchange activities are enhanced by the presence of calcium and the meiosis-specific recombination accessory factor, Hop2-Mnd1. In combination, calcium and Hop2-Mnd1 dramatically increase the rate of DNA strand exchange activity of ehDmc1. The biochemical system described herein provides a basis on which to better understand the role of ehDmc1 and other HR proteins in E. histolytica.
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Affiliation(s)
- Andrew A. Kelso
- Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, United States of America
| | - Amanda F. Say
- Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, United States of America
| | - Deepti Sharma
- Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, United States of America
| | - LeAnna L. Ledford
- Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, United States of America
| | - Audrey Turchick
- Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, United States of America
| | - Christopher A. Saski
- Clemson University Genomics and Computational Biology Laboratory, Institute for Translational Genomics, Clemson, South Carolina, United States of America
| | - Ada V. King
- Department of Biological Sciences, Clemson University, Clemson, South Carolina, United States of America
| | - Christopher C. Attaway
- Department of Biological Sciences, Clemson University, Clemson, South Carolina, United States of America
| | - Lesly A. Temesvari
- Department of Biological Sciences, Clemson University, Clemson, South Carolina, United States of America
- Clemson University School of Health Research, Clemson, South Carolina, United States of America
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, South Carolina, United States of America
| | - Michael G. Sehorn
- Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, United States of America
- Clemson University School of Health Research, Clemson, South Carolina, United States of America
- Center for Optical Materials Science and Engineering Technologies, Clemson University, Clemson, South Carolina, United States of America
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Swann J, Jamshidi N, Lewis NE, Winzeler EA. Systems analysis of host-parasite interactions. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2015; 7:381-400. [PMID: 26306749 PMCID: PMC4679367 DOI: 10.1002/wsbm.1311] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 06/25/2015] [Accepted: 06/29/2015] [Indexed: 12/16/2022]
Abstract
Parasitic diseases caused by protozoan pathogens lead to hundreds of thousands of deaths per year in addition to substantial suffering and socioeconomic decline for millions of people worldwide. The lack of effective vaccines coupled with the widespread emergence of drug‐resistant parasites necessitates that the research community take an active role in understanding host–parasite infection biology in order to develop improved therapeutics. Recent advances in next‐generation sequencing and the rapid development of publicly accessible genomic databases for many human pathogens have facilitated the application of systems biology to the study of host–parasite interactions. Over the past decade, these technologies have led to the discovery of many important biological processes governing parasitic disease. The integration and interpretation of high‐throughput ‐omic data will undoubtedly generate extraordinary insight into host–parasite interaction networks essential to navigate the intricacies of these complex systems. As systems analysis continues to build the foundation for our understanding of host–parasite biology, this will provide the framework necessary to drive drug discovery research forward and accelerate the development of new antiparasitic therapies. WIREs Syst Biol Med 2015, 7:381–400. doi: 10.1002/wsbm.1311 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Justine Swann
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA
| | - Neema Jamshidi
- Department of Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, USA.,Institute of Engineering in Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Nathan E Lewis
- Department of Pediatrics and Novo Nordisk Foundation Center for Biosustainability, University of California, San Diego, La Jolla, CA, USA
| | - Elizabeth A Winzeler
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA
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67
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Watanabe K, Petri WA. Molecular biology research to benefit patients with Entamoeba histolytica infection. Mol Microbiol 2015; 98:208-17. [PMID: 26173474 DOI: 10.1111/mmi.13131] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/13/2015] [Indexed: 12/28/2022]
Abstract
The development of molecular microbiology has made it possible for us to deepen our understanding of the pathogenesis of amebiasis. Research using the trophozoite form of Entamoeba histolytica has clearly shown us the importance of the interface between the parasite and host cells in vitro. Immuno-pathogenesis after excystation was similarly well advanced by the use of a novel murine model of amebic colitis. However, it is still challenging to apply these findings to clinical and epidemiological settings. This is mainly because of the lack of a complete infection animal model of amebiasis by oral-fecal infection. Moreover, in vitro experiments have predominantly been performed using the same axenic cultured strain HM-1: IMSS isolated about 50 years ago, whereas highly diverse strains are prevalent all over the world. Translational research informed by clinical observations has the greatest potential for the development of effective interventions. Here, we highlight discoveries of the experiments designed from cohort observation and discuss remaining problems to be solved.
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Affiliation(s)
- Koji Watanabe
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA, USA.,AIDS Clinical Center, National Center for Global Health and Medicine, Tokyo, Japan
| | - William A Petri
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA, USA
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Zhang H, Ehrenkaufer GM, Manna D, Hall N, Singh U. High Throughput Sequencing of Entamoeba 27nt Small RNA Population Reveals Role in Permanent Gene Silencing But No Effect on Regulating Gene Expression Changes during Stage Conversion, Oxidative, or Heat Shock Stress. PLoS One 2015; 10:e0134481. [PMID: 26248204 PMCID: PMC4527709 DOI: 10.1371/journal.pone.0134481] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 07/10/2015] [Indexed: 01/09/2023] Open
Abstract
The human parasite Entamoeba histolytica has an active RNA interference (RNAi) pathway with an extensive repertoire of 27nt small RNAs that silence genes. However the role of this pathway in regulating amebic biology remains unknown. In this study, we address whether silencing via 27nt small RNAs may be a mechanism for controlling gene expression changes during conversion between the trophozoite and cyst stages of the parasite. We sequenced small RNA libraries generated from trophozoites, early cysts, mature cysts, and excysting cells and mapped them to the E. invadens genome. Our results show that, as in E. histolytica, small RNAs in E. invadens are largely ~27nt in length, have an unusual 5'-polyphosphate structure and mediate gene silencing. However, when comparing the libraries from each developmental time-point we found few changes in the composition of the small RNA populations. Furthermore, genes targeted by small RNAs were permanently silenced with no changes in transcript abundance during development. Thus, the E. invadens 27nt small RNA population does not mediate gene expression changes during development. In order to assess the generalizability of our observations, we examined whether small RNAs may be regulating gene expression changes during stress response in E. histolytica. Comparison of the 27nt small RNA populations from E. histolytica trophozoites from basal conditions, or after heat shock or exposure to oxidative stress showed few differences. Similar to data in E. invadens development, genes targeted by small RNAs were consistently silenced and did not change expression under tested stress conditions. Thus, the biological roles of the 27nt small RNA population in Entamoeba remain elusive. However, as the first characterization of the RNAi pathway in E. invadens these data serve as a useful resource for the study of Entamoeba development and open the door to the development of RNAi-based gene silencing tools in E. invadens.
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Affiliation(s)
- Hanbang Zhang
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Gretchen M. Ehrenkaufer
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Dipak Manna
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Neil Hall
- Center for Genomic Research, Institute of Integrative Biology, Biosciences Building, University of Liverpool, Liverpool, United Kingdom
| | - Upinder Singh
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail:
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Cai Z, Jiang X, Pan Y, Chen L, Zhang L, Zhu K, Cai Y, Ling Y, Chen F, Xu X, Chen M. Transcriptomic analysis of hepatic responses to testosterone deficiency in miniature pigs fed a high-cholesterol diet. BMC Genomics 2015; 16:59. [PMID: 25887406 PMCID: PMC4328429 DOI: 10.1186/s12864-015-1283-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 01/26/2015] [Indexed: 12/15/2022] Open
Abstract
Background Recent studies have indicated that low serum testosterone levels are associated with increased risk of developing hepatic steatosis; however, the mechanisms mediating this phenomenon have not been fully elucidated. To gain insight into the role of testosterone in modulating hepatic steatosis, we investigated the effects of testosterone on the development of hepatic steatosis in pigs fed a high-fat and high-cholesterol (HFC) diet and profiled hepatic gene expression by RNA-Seq in HFC-fed intact male pigs (IM), castrated male pigs (CM), and castrated male pigs with testosterone replacement (CMT). Results Serum testosterone levels were significantly decreased in CM pigs, and testosterone replacement attenuated castration-induced testosterone deficiency. CM pigs showed increased liver injury accompanied by increased hepatocellular steatosis, inflammation, and elevated serum alanine aminotransferase levels compared with IM pigs. Moreover, serum levels of total cholesterol, low-density lipoprotein cholesterol, and triglycerides were markedly increased in CM pigs. Testosterone replacement decreased serum and hepatic lipid levels and improved liver injury in CM pigs. Compared to IM and CMT pigs, CM pigs had lower serum levels of superoxide dismutase but higher levels of malondialdehyde. Gene expression analysis revealed that upregulated genes in the livers of CM pigs were mainly enriched for genes mediating immune and inflammatory responses, oxidative stress, and apoptosis. Surprisingly, the downregulated genes mainly included those that regulate metabolism-related processes, including fatty acid oxidation, steroid biosynthesis, cholesterol and bile acid metabolism, and glucose metabolism. KEGG analysis showed that metabolic pathways, fatty acid degradation, pyruvate metabolism, the tricarboxylic acid cycle, and the nuclear factor-kappaB signaling pathway were the major pathways altered in CM pigs. Conclusions This study demonstrated that testosterone deficiency aggravated hypercholesterolemia and hepatic steatosis in pigs fed an HFC diet and that these effects could be reversed by testosterone replacement therapy. Impaired metabolic processes, enhanced immune and inflammatory responses, oxidative stress, and apoptosis may contribute to the increased hepatic steatosis induced by testosterone deficiency and an HFC diet. These results deepened our understanding of the molecular mechanisms of testosterone deficiency-induced hepatic steatosis and provided a foundation for future investigations. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1283-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zhaowei Cai
- Laboratory Animal Research Center, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
| | - Xiaoling Jiang
- Department of Cancer Genetics, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY, 14263, USA.
| | - Yongming Pan
- Laboratory Animal Research Center, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
| | - Liang Chen
- Laboratory Animal Research Center, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
| | - Lifan Zhang
- College of Animal Science, Nanjing Agricultural University, Nanjing, 310058, China.
| | - Keyan Zhu
- Laboratory Animal Research Center, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
| | - Yueqin Cai
- Laboratory Animal Research Center, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
| | - Yun Ling
- Laboratory Animal Research Center, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
| | - Fangming Chen
- Laboratory Animal Research Center, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
| | - Xiaoping Xu
- Laboratory Animal Research Center, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
| | - Minli Chen
- Laboratory Animal Research Center, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
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Abstract
A key part of the life cycle of an organism is reproduction. For a number of important protist parasites that cause human and animal disease, their sexuality has been a topic of debate for many years. Traditionally, protists were considered to be primitive relatives of the ‘higher’ eukaryotes, which may have diverged prior to the evolution of sex and to reproduce by binary fission. More recent views of eukaryotic evolution suggest that sex, and meiosis, evolved early, possibly in the common ancestor of all eukaryotes. However, detecting sex in these parasites is not straightforward. Recent advances, particularly in genome sequencing technology, have allowed new insights into parasite reproduction. Here, we review the evidence on reproduction in parasitic protists. We discuss protist reproduction in the light of parasitic life cycles and routes of transmission among hosts.
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71
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Entamoeba histolytica adaptation to glucose starvation: a matter of life and death. Curr Opin Microbiol 2014; 20:139-45. [DOI: 10.1016/j.mib.2014.06.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 06/11/2014] [Accepted: 06/13/2014] [Indexed: 12/25/2022]
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Manna D, Ehrenkaufer GM, Singh U. Regulation of gene expression in the protozoan parasite Entamoeba invadens: identification of core promoter elements and promoters with stage-specific expression patterns. Int J Parasitol 2014; 44:837-45. [PMID: 25075445 DOI: 10.1016/j.ijpara.2014.06.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 06/25/2014] [Accepted: 06/25/2014] [Indexed: 02/04/2023]
Abstract
Developmental switching between life-cycle stages is a common feature among many pathogenic organisms. Entamoeba histolytica is an important human pathogen and is a leading parasitic cause of death globally. During its life cycle, Entamoeba converts between cysts (essential for disease transmission) and trophozoites (responsible for tissue invasion). Despite being central to its biology, the triggers that are involved in the developmental pathways of this parasite are not well understood. In order to define the transcriptional network associated with stage conversion we used Entamoeba invadens which serves as a model system for Entamoeba developmental biology, and performed RNA sequencing at different developmental time points. In this study RNA-Seq data was utilised to define basal transcriptional control elements as well as to identify promoters which regulate stage-specific gene expression patterns. We discovered that the 5' and 3' untranslated regions of E. invadens genes are short, a median of 20 nucleotides (nt) and 26 nt respectively. Bioinformatics analysis of DNA sequences proximate to the start and stop codons identified two conserved motifs: (i) E. invadens Core Promoter Motif - GAAC-Like (EiCPM-GL) (GAACTACAAA), and (ii) E. invadens 3'-U-Rich Motif (Ei3'-URM) (TTTGTT) in the 5' and 3' flanking regions, respectively. Electrophoretic mobility shift assays demonstrated that both motifs specifically bind nuclear protein(s) from E. invadens trophozoites. Additionally, we identified select genes with stage-specific expression patterns and analysed the ability of each gene promoter to drive a luciferase reporter gene during the developmental cycle. This approach confirmed three trophozoite-specific, four encystation-specific and two excystation-specific promoters. This work lays the framework for use of stage-specific promoters to express proteins of interest in a particular life-cycle stage, adding to the molecular toolbox for genetic manipulation of E. invadens and allowing further dissection of factors controlling Entamoeba developmental biology.
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Affiliation(s)
- Dipak Manna
- Division of Infectious Diseases, Department of Internal Medicine, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA
| | - Gretchen M Ehrenkaufer
- 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, 300 Pasteur Drive, Stanford, CA 94305, USA.
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Jeelani G, Nozaki T. Metabolomic analysis of Entamoeba: applications and implications. Curr Opin Microbiol 2014; 20:118-24. [PMID: 24950028 DOI: 10.1016/j.mib.2014.05.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 04/18/2014] [Accepted: 05/23/2014] [Indexed: 12/21/2022]
Abstract
Entamoeba histolytica is an enteric protozoan parasite that causes hemorrhagic dysentery and extraintestinal abscesses in millions of inhabitants of endemic areas. The genome of E. histolytica has already been sequenced and used to predict the metabolic potential of the organism. Since nearly 56% of the E. histolytica genes remain unannotated, correlative 'omics' analyses of genomics, transcriptomics, proteomics, and biochemical metabolic profiling are essential in uncovering new, or poorly understood metabolic pathways. Metabolomics aims at understanding biology by comprehensive metabolite profiling. In this review, we discuss recent metabolomics approaches to elucidate unidentified metabolic systems of this pathogen and also discuss future applications of metabolomics to understand the biology and pathogenesis of E. histolytica.
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Affiliation(s)
- Ghulam Jeelani
- Department of Parasitology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Tomoyoshi Nozaki
- Department of Parasitology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan; Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
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74
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Abstract
Entamoeba histolytica is the third-leading cause of parasitic mortality globally. E. histolytica infection generally does not cause symptoms, but the parasite has potent pathogenic potential. The origins, benefits, and triggers of amoebic virulence are complex. Amoebic pathogenesis entails depletion of the host mucosal barrier, adherence to the colonic lumen, cytotoxicity, and invasion of the colonic epithelium. Parasite damage results in colitis and, in some cases, disseminated disease. Both host and parasite genotypes influence the development of disease, as do the regulatory responses they govern at the host-pathogen interface. Host environmental factors determine parasite transmission and shape the colonic microenvironment E. histolytica infects. Here we highlight research that illuminates novel links between host, parasite, and environmental factors in the regulation of E. histolytica virulence.
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Affiliation(s)
- Chelsea Marie
- Division of Infectious Diseases and International Health, University of Virginia School of Medicine, Charlottesville, Virginia 22908; ,
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Faso C, Bischof S, Hehl AB. The proteome landscape of Giardia lamblia encystation. PLoS One 2013; 8:e83207. [PMID: 24391747 PMCID: PMC3877021 DOI: 10.1371/journal.pone.0083207] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 11/09/2013] [Indexed: 11/18/2022] Open
Abstract
Giardia lamblia is an intestinal protozoan parasite required to survive in the environment in order to be transmitted to a new host. To ensure parasite survival, flagellated trophozoites colonizing the small intestine differentiate into non-motile environmentally-resistant cysts which are then shed in the environment. This cell differentiation process called encystation is characterized by significant morphological remodeling which includes secretion of large amounts of cyst wall material. Although much is known about the transcriptional regulation of encystation and the synthesis and trafficking of cyst wall material, the investigation of global changes in protein content and abundance during G. lamblia encystation is still unaddressed. In this study, we report on the quantitative analysis of the G. lamblia proteome during encystation using tandem mass spectrometry. Quantification of more than 1000 proteins revealed major changes in protein abundance in early, mid and late encystation, notably in constitutive secretory protein trafficking. Early stages of encystation were marked by a striking decrease of endoplasmic reticulum-targeted variant-specific surface proteins and significant increases in cytoskeleton regulatory components, NEK protein kinases and proteins involved in protein folding and glycolysis. This was in stark contrast to cells in the later stages of encystation which presented a surprisingly similar proteome composition to non-encysting trophozoites. Altogether these data constitute the first quantitative atlas of the Giardia proteome covering the whole process of encystation and point towards an important role for post-transcriptional control of gene expression in Giardia differentiation. Furthermore, our data provide a valuable resource for the community-based annotation effort of the G. lamblia genome, where almost 70% of all predicted gene models remains “hypothetical”.
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Affiliation(s)
- Carmen Faso
- Institute of Parasitology, University of Zurich, Zurich, Switzerland
- * E-mail: (ABH); (CF)
| | | | - Adrian B. Hehl
- Institute of Parasitology, University of Zurich, Zurich, Switzerland
- * E-mail: (ABH); (CF)
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