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: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [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
|
Nagode A, Vanbeselaere J, Dutkiewicz Z, Kaltenbrunner S, Wilson IBH, Duchêne M. Molecular characterisation of Entamoeba histolytica UDP-glucose 4-epimerase, an enzyme able to provide building blocks for cyst wall formation. PLoS Negl Trop Dis 2023; 17:e0011574. [PMID: 37616327 PMCID: PMC10482301 DOI: 10.1371/journal.pntd.0011574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 09/06/2023] [Accepted: 08/06/2023] [Indexed: 08/26/2023] Open
Abstract
In the human host, the protozoan parasite Entamoeba histolytica is adapted to a non-invasive lifestyle in the colon as well as to an invasive lifestyle in the mesenterial blood vessels and the liver. This means to cope with bacteria and human cells as well as various metabolic challenges. Galactose and N-acetylgalactosamine (GalNAc) are sugars of great importance for the amoebae, they attach to the host mucus and enterocytes via their well-studied Gal/GalNAc specific lectin, they carry galactose residues in their surface glycans, and they cleave GalNAc from host mucins. The enzyme UDP-glucose 4-epimerase (GalE) works as a bridge between the galactose and glucose worlds, it can help to generate glucose for glycolysis from phagocytosis products containing galactose as well as providing UDP-galactose necessary for the biosynthesis of galactose-containing surface components. E. histolytica contains a single galE gene. We recombinantly expressed the enzyme in Escherichia coli and used a spectrophotometric assay to determine its temperature and pH dependency (37°C, pH 8.5), its kinetics for UDP-glucose (Km = 31.82 μM, Vmax = 4.31 U/mg) and substrate spectrum. As observed via RP-HPLC, the enzyme acts on UDP-Glc/Gal as well as UDP-GlcNAc/GalNAc. Previously, Trypanosoma brucei GalE and the bloodstream form of the parasite were shown to be susceptible to the three compounds ebselen, a selenoorganic drug with antioxidant properties, diethylstilbestrol, a mimic of oestrogen with anti-inflammatory properties, and ethacrynic acid, a loop diuretic used to treat oedema. In this study, the three compounds had cytotoxic activity against E. histolytica, but only ebselen inhibited the recombinant GalE with an IC50 of 1.79 μM (UDP-Gal) and 1.2 μM (UDP-GalNAc), suggesting that the two other compounds are active against other targets in the parasite. The importance of the ability of GalE to interconvert UDP-GalNAc and UDP-GlcNAc may be that the trophozoites can generate precursors for their own cyst wall from the sugar subunits cleaved from host mucins. This finding advances our understanding of the biochemical interactions of E. histolytica in its colonic environment.
Collapse
Affiliation(s)
- Anna Nagode
- Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | | | | | - Samantha Kaltenbrunner
- Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Iain B. H. Wilson
- Department of Chemistry, Universität für Bodenkultur, Vienna, Austria
| | - Michael Duchêne
- Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| |
Collapse
|
3
|
Becker C, Adam A, Dommisch H, Stach T, Schaefer AS. In vitro induction of Entamoeba gingivalis cyst-like structures from trophozoites in response to antibiotic treatment. Front Cell Infect Microbiol 2023; 13:1201394. [PMID: 37469604 PMCID: PMC10352839 DOI: 10.3389/fcimb.2023.1201394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 06/16/2023] [Indexed: 07/21/2023] Open
Abstract
Background Entamoeba gingivalis (E. gingivalis) is an anaerobic protozoan that is strongly associated with inflamed periodontal pockets. It is able to invade the mucosal epithelium of the human host, where it can feed on epithelial cells and elicit a severe innate immune response. Unlike other Entamoeba species, it is considered that E. gingivalis cannot form cysts, because it is a non-infectious protozoan. The lack of encystation capability would make it susceptible to periodontal treatment. However, it is not clear how the human host becomes infected with E. gingivalis trophozoites. We investigated the ability of E. gingivalis to encapsulate in response to an unfavorable environment in vitro. Methods Different strains of E. gingivalis, isolated from inflamed periodontal pocket samples, were cultured for 8 days in the presence or absence of the antimicrobials amoxycillin and metronidazole. To reveal cyst formation, we investigated the morphology and ultrastructure of the amoeba by light, fluorescence, transmission and scanning electron microscopy. We also used the fluorescent dye calcofluor white M2R to demonstrate chitin present in the cyst wall. Results We observed exocysts and an intra-cystic space separating the encapsulated trophozoite from the environment. Remarkably, cysts showed a smooth surface, polygonal edges and smaller size compared to free-living trophozoites. In addition, encapsulated trophozoites that detached from the cyst wall had a dense cytoplasma without phagocytic vesicles. The cyst walls consisted of chitin as in other Entamoba species. The encapsulated trophozoids were mononuclear after antibioticinduced encapsulation. Discussion We conclude that E. gingivalis cyst formation has significant implications for dissemination and infection and may explain why established treatment approaches often fail to halt periodontal tissue destruction during periodontitis and peri-implantitis.
Collapse
Affiliation(s)
- Christin Becker
- Molecular Genetics of Oral Inflammatory Diseases Group, Institute for Dental and Craniofacial Sciences, Department of Periodontology, Oral Medicine and Oral Surgery, Charité – University Medicine Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Aysegül Adam
- Molecular Genetics of Oral Inflammatory Diseases Group, Institute for Dental and Craniofacial Sciences, Department of Periodontology, Oral Medicine and Oral Surgery, Charité – University Medicine Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Henrik Dommisch
- Molecular Genetics of Oral Inflammatory Diseases Group, Institute for Dental and Craniofacial Sciences, Department of Periodontology, Oral Medicine and Oral Surgery, Charité – University Medicine Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Thomas Stach
- Department of Molecular Parasitology, Institute of Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Arne S. Schaefer
- Molecular Genetics of Oral Inflammatory Diseases Group, Institute for Dental and Craniofacial Sciences, Department of Periodontology, Oral Medicine and Oral Surgery, Charité – University Medicine Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| |
Collapse
|
4
|
Dziedzic I, Voronkina A, Pajewska-Szmyt M, Kotula M, Kubiak A, Meissner H, Duminis T, Ehrlich H. The Loss of Structural Integrity of 3D Chitin Scaffolds from Aplysina aerophoba Marine Demosponge after Treatment with LiOH. Mar Drugs 2023; 21:334. [PMID: 37367659 DOI: 10.3390/md21060334] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 05/25/2023] [Accepted: 05/28/2023] [Indexed: 06/28/2023] Open
Abstract
Aminopolysaccharide chitin is one of the main structural biopolymers in sponges that is responsible for the mechanical stability of their unique 3D-structured microfibrous and porous skeletons. Chitin in representatives of exclusively marine Verongiida demosponges exists in the form of biocomposite-based scaffolds chemically bounded with biominerals, lipids, proteins, and bromotyrosines. Treatment with alkalis remains one of the classical approaches to isolate pure chitin from the sponge skeleton. For the first time, we carried out extraction of multilayered, tube-like chitin from skeletons of cultivated Aplysina aerophoba demosponge using 1% LiOH solution at 65 °C following sonication. Surprisingly, this approach leads not only to the isolation of chitinous scaffolds but also to their dissolution and the formation of amorphous-like matter. Simultaneously, isofistularin-containing extracts have been obtained. Due to the absence of any changes between the chitin standard derived from arthropods and the sponge-derived chitin treated with LiOH under the same experimental conditions, we suggest that bromotyrosines in A. aerophoba sponge represent the target for lithium ion activity with respect to the formation of LiBr. This compound, however, is a well-recognized solubilizing reagent of diverse biopolymers including cellulose and chitosan. We propose a possible dissolution mechanism of this very special kind of sponge chitin.
Collapse
Affiliation(s)
- Izabela Dziedzic
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614 Poznan, Poland
- Center for Advanced Technologies, Adam Mickiewicz University, Uniwersytetu Poznańskiego 10, 61-614 Poznan, Poland
| | - Alona Voronkina
- Department of Pharmacy, National Pirogov Memorial Medical University, Pirogov Str. 56, 21018 Vinnytsia, Ukraine
- Institute of Electronics and Sensor Materials, TU Bergakademie Freiberg, Gustav Zeuner Str. 3, 09599 Freiberg, Germany
| | - Martyna Pajewska-Szmyt
- Center for Advanced Technologies, Adam Mickiewicz University, Uniwersytetu Poznańskiego 10, 61-614 Poznan, Poland
| | - Martyna Kotula
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614 Poznan, Poland
- Center for Advanced Technologies, Adam Mickiewicz University, Uniwersytetu Poznańskiego 10, 61-614 Poznan, Poland
| | - Anita Kubiak
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614 Poznan, Poland
- Center for Advanced Technologies, Adam Mickiewicz University, Uniwersytetu Poznańskiego 10, 61-614 Poznan, Poland
| | - Heike Meissner
- Department of Prosthetic Dentistry, Faculty of Medicine, University Hospital Carl Gustav Carus of Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
| | - Tomas Duminis
- Center for Advanced Technologies, Adam Mickiewicz University, Uniwersytetu Poznańskiego 10, 61-614 Poznan, Poland
| | - Hermann Ehrlich
- Center for Advanced Technologies, Adam Mickiewicz University, Uniwersytetu Poznańskiego 10, 61-614 Poznan, Poland
| |
Collapse
|
5
|
Wesel J, Shuman J, Bastuzel I, Dickerson J, Ingram-Smith C. Encystation of Entamoeba histolytica in Axenic Culture. Microorganisms 2021; 9:873. [PMID: 33919506 PMCID: PMC8074197 DOI: 10.3390/microorganisms9040873] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 04/15/2021] [Accepted: 04/16/2021] [Indexed: 12/16/2022] Open
Abstract
Entamoeba histolytica is a parasitic protozoan that causes amoebic dysentery, which affects approximately 90 million people each year worldwide. E. histolytica is transmitted through ingestion of food and water contaminated with the cyst form, which undergoes excystation in the small intestine to the trophozoite form that colonizes the large intestine. The reptile pathogen Entamoeba invadens has served as a model for studying stage conversion between the trophozoite and cyst form due to lack of reproducible encystation of E. histolytica in the laboratory. Although much has been learned about encystation and excystation using E. invadens, the findings do not fully translate to E. histolytica due to the extensive genetic and host differences between these species. Here, we present the first reproducible encystation of E. histolytica in vitro. The cysts produced were viable and displayed the four characteristic hallmarks: round shape, chitinous cell wall, tetranucleation, and detergent resistance. Using flow cytometry analysis, glucose limitation and high cell density were key for encystation, as for E. invadens. Entry into encystation was enhanced by the short-chain fatty acids acetate and propionate, unlike for E. invadens. This new model will now allow the further study of E. histolytica stage conversion, transmission, and treatment.
Collapse
Affiliation(s)
- Jordan Wesel
- Department of Genetics and Biochemistry, Clemson University, Clemson, SC 29634, USA; (J.W.); (J.S.); (I.B.); (J.D.)
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, SC 29634, USA
| | - Jennifer Shuman
- Department of Genetics and Biochemistry, Clemson University, Clemson, SC 29634, USA; (J.W.); (J.S.); (I.B.); (J.D.)
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, SC 29634, USA
| | - Irem Bastuzel
- Department of Genetics and Biochemistry, Clemson University, Clemson, SC 29634, USA; (J.W.); (J.S.); (I.B.); (J.D.)
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, SC 29634, USA
| | - Julie Dickerson
- Department of Genetics and Biochemistry, Clemson University, Clemson, SC 29634, USA; (J.W.); (J.S.); (I.B.); (J.D.)
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, SC 29634, USA
| | - Cheryl Ingram-Smith
- Department of Genetics and Biochemistry, Clemson University, Clemson, SC 29634, USA; (J.W.); (J.S.); (I.B.); (J.D.)
- Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, SC 29634, USA
| |
Collapse
|
6
|
Stage-Specific De Novo Synthesis of Very-Long-Chain Dihydroceramides Confers Dormancy to Entamoeba Parasites. mSphere 2021; 6:6/2/e00174-21. [PMID: 33731470 PMCID: PMC8546694 DOI: 10.1128/msphere.00174-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Amoebiasis is a parasitic disease caused by Entamoeba histolytica infection and is a serious public health problem worldwide due to ill-prepared preventive measures as well as its high morbidity and mortality rates. Amoebiasis transmission is solely mediated by cysts. Cysts are produced by the differentiation of proliferative trophozoites in a process termed "encystation." Entamoeba encystation is a fundamental cell differentiation process and proceeds with substantial changes in cell metabolites, components, and morphology, which occur sequentially in an orchestrated manner. Lipids are plausibly among these metabolites that function as key factors for encystation. However, a comprehensive lipid analysis has not been reported, and the involved lipid metabolic pathways remain largely unknown. Here, we exploited the state-of-the-art untargeted lipidomics and characterized 339 molecules of 17 lipid subclasses. Of these, dihydroceramide (Cer-NDS) was found to be among the most induced lipid species during encystation. Notably, in encysting cells, amounts of Cer-NDS containing very long N-acyl chains (≥26 carbon) were more than 30-fold induced as the terminal product of a de novo metabolic pathway. We also identified three ceramide synthase genes responsible for producing the very-long-chain Cer-NDS molecules. These genes were upregulated during encystation. Furthermore, these ceramide species were shown to be indispensable for generating membrane impermeability, a prerequisite for becoming dormant cyst that shows resistance to environmental assault inside and outside the host for transmission. Hence, the lipid subclass of Cer-NDS plays a crucial role for Entamoeba cell differentiation and morphogenesis by alternating the membrane properties.IMPORTANCE Entamoeba is a protozoan parasite that thrives in its niche by alternating its two forms between a proliferative trophozoite and dormant cyst. Cysts are the only form able to transmit to a new host and are differentiated from trophozoites in a process termed "encystation." During Entamoeba encystation, cell metabolites, components, and morphology drastically change, which occur sequentially in an orchestrated manner. Lipids are plausibly among these metabolites. However, the involved lipid species and their metabolic pathways remain largely unknown. Here, we identified dihydroceramides (Cer-NDSs) containing very long N-acyl chains (C26 to C30) as a key metabolite for Entamoeba encystation by our state-of-the-art untargeted lipidomics. We also showed that these Cer-NDSs are critical to generate the membrane impermeability, a prerequisite for this parasite to show dormancy as a cyst that repels substances and prevents water loss. Hence, ceramide metabolism is essential for Entamoeba to maintain the parasitic lifestyle.
Collapse
|
7
|
Rawat A, Singh P, Jyoti A, Kaushik S, Srivastava VK. Averting transmission: A pivotal target to manage amoebiasis. Chem Biol Drug Des 2020; 96:731-744. [PMID: 32356312 DOI: 10.1111/cbdd.13699] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 04/16/2020] [Accepted: 04/19/2020] [Indexed: 12/18/2022]
Abstract
Amoebiasis is a parasitic infectious disease caused by the enteric protozoan Entamoeba histolytica, a leading basis of deaths accounted to parasites, succeeding malaria and schistosomiasis. Conventional treatment methodologies used to deal with amoebiasis mainly rely on the administration of anti-amoebic compounds and vaccines but are often linked with substantial side-effects on the patient. Besides, cases of development of drug resistance in protozoans have been recorded, contributing further to the reduction in the efficiency of the treatment. Loopholes in the efficacious management of the disease call for the development of novel methodologies to manage amoebiasis. A way to achieve this is by targeting the essential metabolic processes of 'encystation' and 'excystation', and the associated biomolecules, thus interrupting the biphasic life cycle of the parasite. Technologies like the CRISPR-Cas9 system can efficiently be exploited to discover novel and essential molecules that regulate the protozoan's metabolism, while efficiently manipulating and managing the known drug targets, leading to an effective halt and forestall to the enteric infection. This review presents a perspective on these essential metabolic processes and the associated molecules that can be targeted efficaciously to prevent the transmission of amoebiasis, thus managing the disease and proving to be a fruitful endeavour.
Collapse
Affiliation(s)
- Aadish Rawat
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
| | - Parikshit Singh
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
| | - Anupam Jyoti
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
| | - Sanket Kaushik
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
| | | |
Collapse
|
8
|
Nayak S, Ghosh SK. Nucleotide sugar transporters of Entamoeba histolytica and Entamoeba invadens involved in chitin synthesis. Mol Biochem Parasitol 2019; 234:111224. [PMID: 31585127 DOI: 10.1016/j.molbiopara.2019.111224] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 09/24/2019] [Accepted: 09/27/2019] [Indexed: 11/26/2022]
Abstract
Chitin, a homopolymer of β-(1,4) linked N-acetylglucosamine (GlcNAc), is a major component of cyst wall in the protozoan parasites Entamoeba histolytica (Eh) and Entamoeba invadens (Ei). The Entamoeba chitin synthase makes chitin at the vesicular membrane rather than the plasma membrane in fungi, even though the chemistry of chitin synthesis is most likely the same. However, the role of nucleotide sugar transporter(s) (NSTs) that are involved in chitin synthesis in Entamoeba are not yet established. In this study, we have identified the putative UDP-GlcNAc transporter (EiNst5) of Ei by BLASTP analysis using the amino acid sequence of EhNst3, the UDP-GlcNAc transporter of Eh. Heterologous expression of both EhNst3 and EiNst5 was found to complement the function of Yea4p (UDP-GlcNAc transporter of S. cerevisiae) in YEA4 null mutant and increased the cell wall chitin content. Like Yea4p in S. cerevisiae, Myc-epitope tagged EhNst3 and EiNst5 were localized to the endoplasmic reticulum in Δyea4 cells. The EiNST5 transcript was up-regulated during the in vitro encystation and oxidative stress in E. invadens. Similar up-regulation was also seen for EhNST3 under oxidative stress in E. histolytica. Down-regulation of EiNst5 expression using gene-specific dsRNA significantly reduced cyst formation during in vitro encystation in E. invadens. Our observations suggest for the first time the involvement of EhNst3 and EiNst5 in chitin synthesis and so in encystation of Entamoeba.
Collapse
Affiliation(s)
- Santoshi Nayak
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, 721 302, India.
| | - Sudip K Ghosh
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, 721 302, India.
| |
Collapse
|
9
|
Chitin Prevalence and Function in Bacteria, Fungi and Protists. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1142:19-59. [DOI: 10.1007/978-981-13-7318-3_3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
10
|
Tabata E, Kashimura A, Kikuchi A, Masuda H, Miyahara R, Hiruma Y, Wakita S, Ohno M, Sakaguchi M, Sugahara Y, Matoska V, Bauer PO, Oyama F. Chitin digestibility is dependent on feeding behaviors, which determine acidic chitinase mRNA levels in mammalian and poultry stomachs. Sci Rep 2018; 8:1461. [PMID: 29362395 PMCID: PMC5780506 DOI: 10.1038/s41598-018-19940-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 01/10/2018] [Indexed: 01/04/2023] Open
Abstract
Chitin, a polymer of N-acetyl-D-glucosamine (GlcNAc), functions as a major structural component in chitin-containing organism including crustaceans, insects and fungi. Recently, we reported that acidic chitinase (Chia) is highly expressed in mouse, chicken and pig stomach tissues and that it can digest chitin in the respective gastrointestinal tracts (GIT). In this study, we focus on major livestock and domestic animals and show that the levels of Chia mRNA in their stomach tissues are governed by the feeding behavior. Chia mRNA levels were significantly lower in the bovine (herbivores) and dog (carnivores) stomach than those in mouse, pig and chicken (omnivores). Consistent with the mRNA levels, Chia protein was very low in bovine stomach. In addition, the chitinolytic activity of E. coli-expressed bovine and dog Chia enzymes were moderately but significantly lower compared with those of the omnivorous Chia enzymes. Recombinant bovine and dog Chia enzymes can degrade chitin substrates under the artificial GIT conditions. Furthermore, genomes of some herbivorous animals such as rabbit and guinea pig do not contain functional Chia genes. These results indicate that feeding behavior affects Chia expression levels as well as chitinolytic activity of the enzyme, and determines chitin digestibility in the particular animals.
Collapse
Affiliation(s)
- Eri Tabata
- Department of Chemistry and Life Science, Kogakuin University, Hachioji, Tokyo, 192-0015, Japan
| | - Akinori Kashimura
- Department of Chemistry and Life Science, Kogakuin University, Hachioji, Tokyo, 192-0015, Japan
| | - Azusa Kikuchi
- Department of Chemistry and Life Science, Kogakuin University, Hachioji, Tokyo, 192-0015, Japan
| | - Hiromasa Masuda
- Department of Chemistry and Life Science, Kogakuin University, Hachioji, Tokyo, 192-0015, Japan
| | - Ryo Miyahara
- Department of Chemistry and Life Science, Kogakuin University, Hachioji, Tokyo, 192-0015, Japan
| | - Yusuke Hiruma
- Department of Chemistry and Life Science, Kogakuin University, Hachioji, Tokyo, 192-0015, Japan
| | - Satoshi Wakita
- Department of Chemistry and Life Science, Kogakuin University, Hachioji, Tokyo, 192-0015, Japan
| | - Misa Ohno
- Department of Chemistry and Life Science, Kogakuin University, Hachioji, Tokyo, 192-0015, Japan
| | - Masayoshi Sakaguchi
- Department of Chemistry and Life Science, Kogakuin University, Hachioji, Tokyo, 192-0015, Japan
| | - Yasusato Sugahara
- Department of Chemistry and Life Science, Kogakuin University, Hachioji, Tokyo, 192-0015, Japan
| | - Vaclav Matoska
- Laboratory of Molecular Diagnostics, Department of Clinical Biochemistry, Hematology and Immunology, Homolka Hospital, Roentgenova 37/2, Prague, 150 00, Czech Republic
| | - Peter O Bauer
- Laboratory of Molecular Diagnostics, Department of Clinical Biochemistry, Hematology and Immunology, Homolka Hospital, Roentgenova 37/2, Prague, 150 00, Czech Republic
- Bioinova Ltd., Videnska 1083, Prague, 142 20, Czech Republic
| | - Fumitaka Oyama
- Department of Chemistry and Life Science, Kogakuin University, Hachioji, Tokyo, 192-0015, Japan.
| |
Collapse
|
11
|
Heterologous expression of an active chitin synthase from Rhizopus oryzae. Fungal Genet Biol 2016; 97:10-17. [PMID: 27777036 DOI: 10.1016/j.fgb.2016.10.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 10/13/2016] [Accepted: 10/20/2016] [Indexed: 11/21/2022]
Abstract
Chitin synthases are highly important enzymes in nature, where they synthesize structural components in species belonging to different eukaryotic kingdoms, including kingdom Fungi. Unfortunately, their structure and the molecular mechanism of synthesis of their microfibrilar product remain largely unknown, probably because no fungal active chitin synthases have been isolated, possibly due to their extreme hydrophobicity. In this study we have turned to the heterologous expression of the transcript from a small chitin synthase of Rhizopus oryzae (RO3G_00942, Chs1) in Escherichia coli. The enzyme was active, but accumulated mostly in inclusion bodies. High concentrations of arginine or urea solubilized the enzyme, but their dilution led to its denaturation and precipitation. Nevertheless, use of urea permitted the purification of small amounts of the enzyme. The properties of Chs1 (Km, optimum temperature and pH, effect of GlcNAc) were abnormal, probably because it lacks the hydrophobic transmembrane regions characteristic of chitin synthases. The product of the enzyme showed that, contrasting with chitin made by membrane-bound Chs's and chitosomes, was only partially in the form of short microfibrils of low crystallinity. This approach may lead to future developments to obtain active chitin synthases that permit understanding their molecular mechanism of activity, and microfibril assembly.
Collapse
|
12
|
Comparative analyses of Legionella species identifies genetic features of strains causing Legionnaires' disease. Genome Biol 2015; 15:505. [PMID: 25370836 DOI: 10.1186/preaccept-1086350395137407] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The genus Legionella comprises over 60 species. However, L. pneumophila and L. longbeachae alone cause over 95% of Legionnaires’ disease. To identify the genetic bases underlying the different capacities to cause disease we sequenced and compared the genomes of L. micdadei, L. hackeliae and L. fallonii (LLAP10), which are all rarely isolated from humans. RESULTS We show that these Legionella species possess different virulence capacities in amoeba and macrophages, correlating with their occurrence in humans. Our comparative analysis of 11 Legionella genomes belonging to five species reveals highly heterogeneous genome content with over 60% representing species-specific genes; these comprise a complete prophage in L. micdadei, the first ever identified in a Legionella genome. Mobile elements are abundant in Legionella genomes; many encode type IV secretion systems for conjugative transfer, pointing to their importance for adaptation of the genus. The Dot/Icm secretion system is conserved, although the core set of substrates is small, as only 24 out of over 300 described Dot/Icm effector genes are present in all Legionella species. We also identified new eukaryotic motifs including thaumatin, synaptobrevin or clathrin/coatomer adaptine like domains. CONCLUSIONS Legionella genomes are highly dynamic due to a large mobilome mainly comprising type IV secretion systems, while a minority of core substrates is shared among the diverse species. Eukaryotic like proteins and motifs remain a hallmark of the genus Legionella. Key factors such as proteins involved in oxygen binding, iron storage, host membrane transport and certain Dot/Icm substrates are specific features of disease-related strains.
Collapse
|
13
|
|
14
|
Gomez-Valero L, Rusniok C, Rolando M, Neou M, Dervins-Ravault D, Demirtas J, Rouy Z, Moore RJ, Chen H, Petty NK, Jarraud S, Etienne J, Steinert M, Heuner K, Gribaldo S, Médigue C, Glöckner G, Hartland EL, Buchrieser C. Comparative analyses of Legionella species identifies genetic features of strains causing Legionnaires’ disease. Genome Biol 2014. [PMID: 25370836 PMCID: PMC4256840 DOI: 10.1186/s13059-014-0505-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background The genus Legionella comprises over 60 species. However, L. pneumophila and L. longbeachae alone cause over 95% of Legionnaires’ disease. To identify the genetic bases underlying the different capacities to cause disease we sequenced and compared the genomes of L. micdadei, L. hackeliae and L. fallonii (LLAP10), which are all rarely isolated from humans. Results We show that these Legionella species possess different virulence capacities in amoeba and macrophages, correlating with their occurrence in humans. Our comparative analysis of 11 Legionella genomes belonging to five species reveals highly heterogeneous genome content with over 60% representing species-specific genes; these comprise a complete prophage in L. micdadei, the first ever identified in a Legionella genome. Mobile elements are abundant in Legionella genomes; many encode type IV secretion systems for conjugative transfer, pointing to their importance for adaptation of the genus. The Dot/Icm secretion system is conserved, although the core set of substrates is small, as only 24 out of over 300 described Dot/Icm effector genes are present in all Legionella species. We also identified new eukaryotic motifs including thaumatin, synaptobrevin or clathrin/coatomer adaptine like domains. Conclusions Legionella genomes are highly dynamic due to a large mobilome mainly comprising type IV secretion systems, while a minority of core substrates is shared among the diverse species. Eukaryotic like proteins and motifs remain a hallmark of the genus Legionella. Key factors such as proteins involved in oxygen binding, iron storage, host membrane transport and certain Dot/Icm substrates are specific features of disease-related strains. Electronic supplementary material The online version of this article (doi:10.1186/s13059-014-0505-0) contains supplementary material, which is available to authorized users.
Collapse
|
15
|
Blank CE. An expansion of age constraints for microbial clades that lack a conventional fossil record using phylogenomic dating. J Mol Evol 2011; 73:188-208. [PMID: 22105429 DOI: 10.1007/s00239-011-9467-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2011] [Accepted: 10/24/2011] [Indexed: 01/22/2023]
Abstract
Most microbial taxa lack a conventional microfossil or biomarker record, and so we currently have little information regarding how old most microbial clades and their associated traits are. Building on the previously published oxygen age constraint, two new age constraints are proposed based on the ability of microbial clades to metabolize chitin and aromatic compounds derived from lignin. Using the archaeal domain of life as a test case, phylogenetic analyses, along with published metabolic and genetic data, showed that members of the Halobacteriales and Thermococcales are able to metabolize chitin. Ancestral state reconstruction combined with phylogenetic analysis of the genes underlying chitin degradation predicted that the ancestors of these two groups were also likely able to metabolize chitin or chitin-related compounds. These two clades were therefore assigned a maximum age of 1.0 Ga (when chitin likely first appeared). Similar analyses also predicted that the ancestor to the Sulfolobus solfataricus-Sulfolobus islandicus clade was able to metabolize phenol using catechol dioxygenase, so this clade was assigned a maximum age of 475 Ma. Inferred ages of archaeal clades using relaxed molecular clocks with the new age constraints were consistent with those inferred with the oxygen age constraints. This work expands our current toolkit to include Paleoproterozoic, Neoproterozoic, and Paleozoic age constraints, and should aid in our ability to phylogenetically reconstruct the antiquity of a wide array of microbial clades and their associated morphological and biogeochemical traits, spanning deep geologic time. Such hypotheses-although built upon evolutionary inferences-are fundamentally testable.
Collapse
Affiliation(s)
- Carrine E Blank
- Department of Geosciences, University of Montana, 32 Campus Drive #1296, Missoula, MT 59812-1296, USA.
| |
Collapse
|
16
|
Cyst and encystment in protozoan parasites: optimal targets for new life-cycle interrupting strategies? Trends Parasitol 2011; 27:450-8. [PMID: 21775209 DOI: 10.1016/j.pt.2011.06.003] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Revised: 06/15/2011] [Accepted: 06/16/2011] [Indexed: 11/24/2022]
Abstract
Certain protozoan parasites use survival strategies to reside outside the host such as the formation of cysts. This dormant and resistant stage results from the complex process of encystment that involves diverse molecular and cellular modifications. The stimuli and changes associated with cyst biogenesis are a matter of ongoing studies in human and animal protozoan parasites such as amoeba and Giardia species because blocking every step in the encystment pathway should, in theory, interrupt their life cycles. The present review thoroughly examines this essential process in those protozoan parasites and discusses the possibility of using that information to develop new kinds of anti-parasite specific and life cycle-interrupting drugs, aimed at holding back the dissemination of these infections.
Collapse
|
17
|
Santos FLN, Gonçalves MDS, Soares NM. Validation and utilization of PCR for differential diagnosis and prevalence determination of Entamoeba histolytica/Entamoeba dispar in Salvador City, Brazil. Braz J Infect Dis 2011. [DOI: 10.1016/s1413-8670(11)70156-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|
18
|
Different structure and mRNA expression of Entamoeba invadens chitinases in the encystation and excystation. Parasitol Res 2011; 109:417-23. [PMID: 21286750 DOI: 10.1007/s00436-011-2270-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Accepted: 01/19/2011] [Indexed: 10/18/2022]
Abstract
Entamoeba histolytica forms chitin-walled cysts during encystation process, where formation of the cyst wall needs not only chitin synthase but also chitinase. During excystation, quadruplet amoebae emerge from the chitin-walled cysts by dissolving the wall, so that chitinase may be necessary for excystation process as well. There is, however, no report on chitinase expression during excystation. In this study, we used Entamoeba invadens, a reptilian amoeba, as a model for encystation and excystation of E. histolytica, and studied chitinase mRNA expression in those processes. Although expression of three E. invadens chitinases designated EiChit1, EiChit2, and EiChit3 during encystation has been reported, we identified another enzyme named as EiChit4 in the E. invadens genome database. Therefore, we investigated the primary structure and mRNA expression of these four chitinases of Ei in the excystation as well as the encystation by real-time reverse transcription polymerase chain reaction (RT-PCR). Like EiChit1, EiChit4 had an 8 × Cys chitin-binding domain (CBD) and a hydrophilic spacer between the CBD and catalytic domain, and was also closer to EiChit1 than EiChit2 and EiChit3 in the phylogenetic tree. During encystation, the expression of all four chitinases increased in the early phase; the increase in EiChit1 and EiChit4 was much higher than in EiChit2 and EiChit3. Then, the expression of all four chitinases sharply decreased in the later phase. In cysts, EiChit1 was most abundantly expressed and EiChit4 was at a lower level, while the expressions of EiChit2 and EiChit3 were virtually absent. Following the induction of excystation, mRNA levels of EiChit1 and EiChit4 in cysts 5 h after induction were significantly lower than those in cysts before induction, while those of EiChit2 and EiChit3 were remarkably higher than before induction. The mRNAs of only EiChit2 and EiChit3 remarkably increased when the excystation was induced in the presence of cytochalasin D. These data demonstrate different structures and expressions of four chitinases in the differentiation of E. invadens.
Collapse
|
19
|
Aguilar-Díaz H, Díaz-Gallardo M, Laclette JP, Carrero JC. In vitro induction of Entamoeba histolytica cyst-like structures from trophozoites. PLoS Negl Trop Dis 2010; 4:e607. [PMID: 20169067 PMCID: PMC2821915 DOI: 10.1371/journal.pntd.0000607] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 12/29/2009] [Indexed: 11/18/2022] Open
Abstract
Inhibition of encystment can be conceived as a potentially useful mechanism to block the transmission of Entamoeba histolytica under natural conditions. Unfortunately, amoeba encystment has not been achieved in vitro and drugs inhibiting the formation of cysts are not available. Luminal conditions inducing encystment in vivo are also unknown, but cellular stress such as exposure to reactive oxygen species from immune cells or intestinal microbiota could be involved. A role for certain divalent cations as cofactors of enzymes involved in excystment has also been described. In this study, we show that trophozoite cultures, treated with hydrogen peroxide in the presence of trace amounts of several cations, transform into small-sized spherical and refringent structures that exhibit resistance to different detergents. Ultrastructural analysis under scanning and transmission electron microscopy revealed multinucleated structures (some with four nuclei) with smooth, thick membranes and multiple vacuoles. Staining with calcofluor white, as well as an ELISA binding assay using wheat germ agglutinin, demonstrated the presence of polymers of N-acetylglucosamine (chitin), which is the primary component of the natural cyst walls. Over-expression of glucosamine 6-phosphate isomerase, likely to be the rate-limiting enzyme in the chitin synthesis pathway, was also confirmed by RT-PCR. These results suggest that E. histolytica trophozoites activated encystment pathways when exposed to our treatment.
Collapse
Affiliation(s)
- Hugo Aguilar-Díaz
- Department of Immunology, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Martha Díaz-Gallardo
- Department of Developmental Genetics and Molecular Physiology, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos, México
| | - Juan P. Laclette
- Department of Immunology, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México, México
- * E-mail: (JPL); (JCC)
| | - Julio C. Carrero
- Department of Immunology, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México, México
- * E-mail: (JPL); (JCC)
| |
Collapse
|
20
|
Dey T, Basu R, Ghosh SK. Entamoeba invadens: Cloning and molecular characterization of chitinases. Exp Parasitol 2009; 123:244-9. [DOI: 10.1016/j.exppara.2009.07.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 06/02/2009] [Accepted: 07/24/2009] [Indexed: 11/29/2022]
|
21
|
Ebert F, Bachmann A, Nakada-Tsukui K, Hennings I, Drescher B, Nozaki T, Tannich E, Bruchhaus I. An Entamoeba cysteine peptidase specifically expressed during encystation. Parasitol Int 2008; 57:521-4. [PMID: 18723116 DOI: 10.1016/j.parint.2008.07.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Revised: 07/11/2008] [Accepted: 07/19/2008] [Indexed: 11/26/2022]
Abstract
Protozoan parasites of the genus Entamoeba possess a considerable number of cysteine peptidases (CPs), the function of most of these molecules for amoeba biology needs to be established. In order to determine whether CPs may play a role during Entamoeba stage conversion from trophozoites into cysts and vice versa, expression of cp genes was analysed in the reptilian parasite Entamoeba invadens, a model organism for studying Entamoeba cyst development. By homology search, 28 papain-like cp genes were identified in public E. invadens genome databases. For eight of these genes the expression profiles during stage conversion was determined. By Northern blot analysis, transcripts for eicp-a9, -b7, -b8 and -c2, respectively, were detected neither in trophozoites or cysts nor at any of the point of times analysed during stage conversion. On the other hand, eicp-a5 is constitutively expressed during all developmental stages, whereas eicp-a3 and eicp-a11, respectively, are trophozoite-specific. Only eicp-b9 was found to be cyst-specific as it is expressed exclusively 18 to 28 h after cyst induction. Cyst-specific expression was confirmed by immunofluorescence microscopy of the corresponding protein EiCP-B9. In immature cysts, the molecule is located in structures that accumulate near the cyst wall, but which are uniformly distributed in mature cysts. The precise function of EiCP-B9 during Entamoeba encystation remains to be determined. However, colocalisation studies with an Entamoeba marker for autophagosomes suggest that EiCP-B9 is not associated with Entamoeba autophagy.
Collapse
Affiliation(s)
- Frank Ebert
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Picazarri K, Nakada-Tsukui K, Nozaki T. Autophagy during proliferation and encystation in the protozoan parasite Entamoeba invadens. Infect Immun 2008; 76:278-88. [PMID: 17923513 PMCID: PMC2223641 DOI: 10.1128/iai.00636-07] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Revised: 06/13/2007] [Accepted: 09/29/2007] [Indexed: 11/20/2022] Open
Abstract
Autophagy is one of the three systems responsible for the degradation of cytosolic proteins and organelles. Autophagy has been implicated in the stress response to starvation, antigen cross-presentation, the defense against invading bacteria and viruses, differentiation, and development. Saccharomyces cerevisiae Atg8 and its mammalian ortholog, LC3, play an essential role in autophagy. The intestinal protozoan parasite Entamoeba histolytica and a related reptilian species, Entamoeba invadens, possess the Atg8 conjugation system, consisting of Atg8, Atg4, Atg3, and Atg7, but lack the Atg5-to-Atg12 conjugation system. Immunofluorescence imaging revealed that polymorphic Atg8-associated structures emerged in the logarithmic growth phase and decreased in the stationary phase and also increased in the early phase of encystation in E. invadens. Immunoblot analysis showed that the increase in phosphatidylethanolamine-conjugated membrane-associated Atg8 was also accompanied by the emergence of Atg8-associated structures during the proliferation and differentiation mentioned above. Specific inhibitors of class I and III phosphatidylinositol 3-kinases simultaneously inhibited both the growth of trophozoites and autophagy and also both encystation and autophagy in E. invadens. These results suggest that the core machinery for autophagy is conserved and plays an important role during proliferation and differentiation in Entamoeba.
Collapse
Affiliation(s)
- Karina Picazarri
- Department of Parasitology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan
| | | | | |
Collapse
|
23
|
Barrón-González MP, Villarreal-Treviño L, Reséndez-Pérez D, Mata-Cárdenas BD, Morales-Vallarta MR. Entamoeba histolytica: cyst-like structures in vitro induction. Exp Parasitol 2007; 118:600-3. [PMID: 18083165 DOI: 10.1016/j.exppara.2007.11.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2007] [Revised: 08/25/2007] [Accepted: 11/02/2007] [Indexed: 11/24/2022]
Abstract
The cyst of Entamoeba histolytica is responsible for amebiasis infection. However, no axenic in vitro system exists that promotes mass encystation for studying this process of this human-infecting parasite. Cyst-like structures of E. histolytica obtained in this work were induced using TYI-S-33 media in combination with enterobacterias Escherichia coli and Enterococcus faecalis conditioned media, high CO2 tension and histamine. Cyst-like structures showed the same characteristics of a typical E. histolytica cyst: aggregation, resistance to 0.15% sarcosyl for 10 min, high signal of fluorescence under UV light when stained with 10% calcofluor M2r and the surface topology showed a wrinkled wall. In addition these structures are multinucleated with condensed chromatin attached to nuclear membrane, contain big vacuoles and ribonucleoproteic helices in the cytoplasm and also present a thin cell wall. Last all characteristics are all the same as a typical of E. histolytica cyst.
Collapse
Affiliation(s)
- M P Barrón-González
- Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, Av. Pedro de Alba y Manuel L. Barragán S/N Ciudad Universitaria, C.P. 66451, A.P. 67-F, San Nicolás de los Garza, Nuevo León, Mexico
| | | | | | | | | |
Collapse
|
24
|
Zhang Y, Foster JM, Nelson LS, Ma D, Carlow CKS. The chitin synthase genes chs-1 and chs-2 are essential for C. elegans development and responsible for chitin deposition in the eggshell and pharynx, respectively. Dev Biol 2006; 285:330-9. [PMID: 16098962 DOI: 10.1016/j.ydbio.2005.06.037] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2005] [Revised: 06/03/2005] [Accepted: 06/17/2005] [Indexed: 11/28/2022]
Abstract
It is widely accepted that chitin is present in nematodes. However, its precise role in embryogenesis is unclear and it is unknown if chitin is necessary in other nematode tissues. Here, we determined the roles of chitin and the two predicted chitin synthase genes in Caenorhabditis elegans by chitin localization and gene disruption. Using a novel probe, we detected chitin in the eggshell and discovered elaborate chitin localization patterns in the pharyngeal lumen walls. Chitin deposition in these two sites is likely regulated by the activities of chs-1 (T25G3.2) and chs-2 (F48A11.1), respectively. Reducing chs-1 gene activity by RNAi led to eggs that were fragile and permeable to small molecules, and in the most severe case, absence of embryonic cell division. Complete loss of function in a chs-1 deletion resulted in embryos that lacked chitin in their eggshells and failed to divide. These results showed that eggshell chitin provides both mechanical support and chemical impermeability essential to developing embryos. Knocking down chs-2 by RNAi caused a defect in the pharynx and led to L1 larval arrest, indicating that chitin is involved in the development and function of the pharynx.
Collapse
Affiliation(s)
- Yinhua Zhang
- New England Biolabs Inc., 240 County Road, Ipswich, MA 01938, USA
| | | | | | | | | |
Collapse
|
25
|
Van Dellen KL, Bulik DA, Specht CA, Robbins PW, Samuelson JC. Heterologous expression of an Entamoeba histolytica chitin synthase in Saccharomyces cerevisiae. EUKARYOTIC CELL 2006; 5:203-6. [PMID: 16400183 PMCID: PMC1360259 DOI: 10.1128/ec.5.1.203-206.2006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Chitin in the cyst wall of Entamoeba histolytica is made by two chitin synthases (Chs), one of which is unique (EhCHS-1) and one of which resembles those of insects and nematodes (EhCHS-2). EhCHS-1 is deposited chitin in the lateral wall of transformed Saccharomyces cerevisiae Chs mutants, independent of accessory proteins (Chs4p to Chs7p) required by yeast Chs3p.
Collapse
Affiliation(s)
- Katrina L Van Dellen
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, 715 Albany St., Evans 426, Boston, Massachusetts 02118, USA
| | | | | | | | | |
Collapse
|
26
|
Vanchinathan P, Brewer JL, Harb OS, Boothroyd JC, Singh U. Disruption of a locus encoding a nucleolar zinc finger protein decreases tachyzoite-to-bradyzoite differentiation in Toxoplasma gondii. Infect Immun 2005; 73:6680-8. [PMID: 16177345 PMCID: PMC1230886 DOI: 10.1128/iai.73.10.6680-6688.2005] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During its life cycle in intermediate hosts, Toxoplasma gondii exists in two interconverting developmental stages: tachyzoites and bradyzoites. This interconversion is essential for the survival and pathogenicity of the parasite, but little is known about the genetic mechanisms that control this process. We have previously generated tachyzoite-to-bradyzoite differentiation (Tbd(-)) mutants using chemical mutagenesis and a green fluorescent protein-based selection strategy. The genetic loci responsible for the Tbd(-) phenotype, however, could not be identified. We have now used an insertional mutagenesis strategy to generate two differentiation mutants: TBD-5 and TBD-6 that switch to bradyzoites at 10 and 50% of wild-type levels, respectively. In TBD-6 there is a single insertion of the mutagenesis vector 164 bp upstream of the transcription start site of a gene encoding a zinc finger protein (ZFP1). Disruption of this locus in wild-type parasites reproduces the decreased stage conversion phenotype. ZFP1 is targeted to the parasite nucleolus by CCHC motifs and significantly altered expression levels are toxic to the parasites. This represents the first identification of a gene necessary for efficient conversion of tachyzoites to bradyzoites.
Collapse
Affiliation(s)
- Padmini Vanchinathan
- Department of Internal Medicine, Division of Infectious Diseases, Stanford University School of Medicine, California 94305-5124, USA
| | | | | | | | | |
Collapse
|
27
|
Foster JM, Zhang Y, Kumar S, Carlow CKS. Parasitic nematodes have two distinct chitin synthases. Mol Biochem Parasitol 2005; 142:126-32. [PMID: 15869814 DOI: 10.1016/j.molbiopara.2005.03.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2005] [Accepted: 03/22/2005] [Indexed: 10/25/2022]
|