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“Feast-Fit-Fist-Feat”: Overview of Free-living Amoeba Interactions with Fungi and Virulence as a Foundation for Success in Battle. CURRENT TROPICAL MEDICINE REPORTS 2021. [DOI: 10.1007/s40475-020-00220-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Anwar A, Siddiqui R, Khan NA. Whole Organism Model to Study Molecular Mechanisms of Differentiation and Dedifferentiation. BIOLOGY 2020; 9:E79. [PMID: 32316619 PMCID: PMC7235994 DOI: 10.3390/biology9040079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/14/2020] [Accepted: 04/15/2020] [Indexed: 12/25/2022]
Abstract
Cancer recurrence has remained a significant challenge, despite advances in therapeutic approaches. In part, this is due to our incomplete understanding of the biology of cancer stem cells and the underlying molecular mechanisms. The phenomenon of differentiation and dedifferentiation (phenotypic switching) is not only unique to stem cells but it is also observed in several other organisms, as well as evolutionary-related microbes. Here, we propose the use of a primitive eukaryotic unicellular organism, Acanthamoeba castellanii, as a model to study the molecular mechanisms of cellular differentiation and dedifferentiation.
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Affiliation(s)
- Areeba Anwar
- Department of Biological Sciences, School of Science and Technology, Sunway University, Bandar Sunway 47500, Malaysia;
| | - Ruqaiyyah Siddiqui
- Department of Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, University City 26666, UAE;
| | - Naveed Ahmed Khan
- Department of Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, University City 26666, UAE;
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Gueudry J, Le Goff L, Compagnon P, Lefevre S, Colasse E, Aknine C, Duval F, François A, Razakandrainibe R, Ballet JJ, Muraine M, Favennec L. Evaluation of voriconazole anti-Acanthamoeba polyphaga in vitro activity, rat cornea penetration and efficacy against experimental rat Acanthamoeba keratitis. J Antimicrob Chemother 2018; 73:1895-1898. [DOI: 10.1093/jac/dky094] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 02/26/2018] [Indexed: 11/15/2022] Open
Affiliation(s)
- Julie Gueudry
- EA3800 ‘Protozooses Transmises par l'Alimentation’ – University of Rouen Normandy, Rouen, France
- Department of Ophthalmology – Charles Nicolle University Hospital, Rouen, France
| | - Laetitia Le Goff
- EA3800 ‘Protozooses Transmises par l'Alimentation’ – University of Rouen Normandy, Rouen, France
| | - Patricia Compagnon
- Department of Clinical Pharmacology – Charles Nicolle University Hospital, Rouen, France
| | - Sabine Lefevre
- Department of Ophthalmology – Charles Nicolle University Hospital, Rouen, France
| | - Elodie Colasse
- Department of Pathological Anatomy and Cytology – Charles Nicolle University Hospital, Rouen, France
| | - Camille Aknine
- EA3800 ‘Protozooses Transmises par l'Alimentation’ – University of Rouen Normandy, Rouen, France
| | - François Duval
- EA3800 ‘Protozooses Transmises par l'Alimentation’ – University of Rouen Normandy, Rouen, France
| | - Arnaud François
- EA3800 ‘Protozooses Transmises par l'Alimentation’ – University of Rouen Normandy, Rouen, France
- Department of Pathological Anatomy and Cytology – Charles Nicolle University Hospital, Rouen, France
| | - Romy Razakandrainibe
- EA3800 ‘Protozooses Transmises par l'Alimentation’ – University of Rouen Normandy, Rouen, France
| | - Jean Jacques Ballet
- EA3800 ‘Protozooses Transmises par l'Alimentation’ – University of Rouen Normandy, Rouen, France
| | - Marc Muraine
- Department of Ophthalmology – Charles Nicolle University Hospital, Rouen, France
| | - Loïc Favennec
- EA3800 ‘Protozooses Transmises par l'Alimentation’ – University of Rouen Normandy, Rouen, France
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Abstract
SUMMARYThe ability of cyst-forming protists such asAcanthamoebato escape death by transforming into a cyst form, that is resistant to harsh physiological, environmental and pharmacological conditions, has continued to pose a serious challenge to human and animal health. A complete understanding of the fundamental principles of genome evolution and biochemical pathways of cellular differentiation offers unprecedented opportunities to counter detrimental outcomes.Acanthamoebacan elude inhospitable conditions by forming cysts. Here we unravel the processes involved in the phenotypic switching ofAcanthamoeba, which are critical in our efforts to find potential targets for chemotherapy.
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Chen L, Orfeo T, Gilmartin G, Bateman E. Mechanism of cyst specific protein 21 mRNA induction during Acanthamoeba differentiation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2004; 1691:23-31. [PMID: 15053921 DOI: 10.1016/j.bbamcr.2003.11.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2003] [Revised: 10/30/2003] [Accepted: 11/14/2003] [Indexed: 11/20/2022]
Abstract
The Acanthamoeba cyst specific protein 21 (CSP21) gene is tightly repressed in growing cells and highly induced early during differentiation into a dormant cyst. This increase is mediated by the rate of transcription of the CSP21 gene as determined by nuclear run-on assays. The promoter region of the CSP21 gene was analyzed by transcript start site mapping and in vitro transcription of wild-type or mutant templates, using extracts from growing cells. A sequence located 3' to a modified TATA box completely inhibits transcription and removal of this region permits robust transcription utilizing a start site approximately 35 base pairs downstream of the TATA box. Sequences 5' to the TATA box had no effect on transcription, suggesting that anti-repression is the only mechanism required for CSP21 induction. Fractionation of nuclear extracts yielded a fraction capable of transcription from the CSP21 promoter, and a fraction containing a promoter-specific repressing activity. Anti-repression may thus be a major mechanism regulating differentiation or maintenance of the proliferative cycle in Acanthamoeba.
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Affiliation(s)
- Li Chen
- Department of Microbiology and Molecular Genetics, Markey Center for Molecular Genetics, University of Vermont, Burlington, VT 05405, USA
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Kahane S, Dvoskin B, Mathias M, Friedman MG. Infection of Acanthamoeba polyphaga with Simkania negevensis and S. negevensis survival within amoebal cysts. Appl Environ Microbiol 2001; 67:4789-95. [PMID: 11571186 PMCID: PMC93233 DOI: 10.1128/aem.67.10.4789-4795.2001] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2001] [Accepted: 07/31/2001] [Indexed: 11/20/2022] Open
Abstract
Simkania negevensis, a novel microorganism belonging to the family Simkaniaceae in the order Chlamydiales, has an intracellular developmental cycle during which two morphological entities, elementary bodies (EB) and reticulate bodies (RB), are seen by electron microscopy. Rates of seropositivity to the organism are high in certain population groups, and S. negevensis has been associated with respiratory illness in humans. This study reports for the first time the ability of S. negevensis to survive and grow inside Acanthamoeba polyphaga in addition to its known ability to grow in cell cultures of human or simian origin. Infectivity of S. negevensis and growth in amoebae were monitored by immunoperoxidase assays. Long-term persistence and exponential growth of S. negevensis in amoebal trophozoites were demonstrated by infectivity assays and by electron microscopy. EB and dividing RB of S. negevensis were observed within inclusion bodies inside A. polyphaga. When S. negevensis-infected A. polyphaga amoebae were exposed to adverse conditions resulting in encystation of the amoebae, several possible outcomes were observed: cysts containing both normal amoebic cytoplasm and S. negevensis; cysts in which S. negevensis cells were relegated to the space between cyst walls; and cysts containing S. negevensis, but apparently lacking amoebal cytoplasm. S. negevensis within dried amoebal cysts was capable of long-term survival. The possibility that amoebae may have a role in natural transmission of S. negevensis needs to be investigated.
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Affiliation(s)
- S Kahane
- Department of Virology, Faculty of Health Sciences, Ben Gurion University of the Negev, Israel
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Orfeo T, Chen L, Huang W, Ward G, Bateman E. Distamycin A selectively inhibits Acanthamoeba RNA synthesis and differentiation. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1446:273-85. [PMID: 10524202 DOI: 10.1016/s0167-4781(99)00076-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The effects of distamycin A on Acanthamoeba transcription, growth and differentiation were determined. Distamycin A inhibits transcription both in vitro and in vivo and can displace from DNA the transcription activator TATA binding protein promoter binding factor (TPBF). Inhibition in vivo is surprisingly selective for large rRNA precursors, 5S rRNA, profilin, S-adenosylmethionine synthetase, and extendin. Transcription from the TATA binding protein (TBP), TPBF, protein disulfide isomerase, tubulin and RNA polymerase II large subunit genes is only slightly inhibited. Moreover the rate of 5S rRNA transcription eventually recovers and exceeds that of untreated cells, while profilin transcription remains inhibited. Distamycin A inhibition is accompanied by a complex pattern of alterations to steady state levels of mRNAs. Actin, profilin and S-adenosylmethionine synthetase mRNAs are degraded, whereas mRNA encoding TBP is increased slightly in abundance. Transcription inhibition is accompanied by cessation of growth and severe morphological changes to Acanthamoeba, which are consistent with loss of production of mRNA encoding cytoskeletal proteins. Distamycin A also prevents starvation-induced differentiation of Acanthamoeba, in part due to complete prevention of cellulose production and cell wall formation.
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Affiliation(s)
- T Orfeo
- Department of Microbiology and Molecular Genetics, Markey Center for Molecular Genetics, University of Vermont, Burlington 05405, USA
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Orfeo T, Bateman E. Transcription by RNA polymerase II during Acanthamoeba differentiation. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1443:297-304. [PMID: 9878798 DOI: 10.1016/s0167-4781(98)00227-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The rates of transcription of several protein coding genes during Acanthamoeba differentiation have been examined by nuclear run-on and RNase protection assays. During early encystment, transcription by RNA polymerase II increases approximately 4-fold, whereas transcription by RNA polymerases I and III is decreased, as previously described. The rates of transcription from a wide variety of individual genes are only slightly affected during the first 16 h of encystment, although profilin gene expression is markedly increased. The levels of mRNAs encoding TPBF, TATA binding protein, cyclin-dependent kinase, protein disulfide isomerase, profilin, myosin II heavy chain, ubiquitin and extendin are stable during mature cyst formation, whereas mRNAs encoding actin, S-adenosyl methionine synthase and tubulin are substantially decreased in abundance within 16 h of starvation-induced encystment. We conclude that in contrast to the negative regulation of large rRNA and 5S rRNA synthesis during differentiation, the RNA polymerase II transcription apparatus is not negatively regulated. Control of Acanthamoeba differentiation is likely to be mediated by positive regulation of genes necessary for cyst maturation.
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Affiliation(s)
- T Orfeo
- Department of Microbiology and Molecular Genetics, Markey Center for Molecular Genetics, University of Vermont, Burlington, VT 05405, USA
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Milligan SM, Band RN. Restriction endonuclease analysis of mitochondrial DNA as an aid in the taxonomy of Naegleria and Vahlkampfia. THE JOURNAL OF PROTOZOOLOGY 1988; 35:198-204. [PMID: 2840491 DOI: 10.1111/j.1550-7408.1988.tb04323.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Using restriction enzyme analysis, mitochondrial DNA fragment patterns from seven strains of pathogenic and nonpathogenic Naegleria and one strain of Vahlkampfia were compared to estimate nucleotide sequence divergence. Significantly high levels of estimated genetic variation between strains of N. gruberi, N. fowleri, and N. jadini support the current taxonomic level of the individual Naegleria species and suggest a distinct phylogeny for each group. Naegleria lovaniensis, strain TS, was shown to have significant nucleotide sequence homology with N. gruberi, strain EGs, suggesting that the two groups share a close taxonomic relationship. The pathogenic strain MB-41 of N. fowleri exhibited distinct genetic divergence from the highly homologous, pathogenic strain Nf66 and the drug-cured strain 6088. Morphologically distinct strains EGs and 1518/la of N. gruberi exhibited significantly large sequence divergence consistent with a more distant taxonomic relationship. Amoebae from the genus Vahlkampfia expressed genetic similarity with strains of N. gruberi.
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Affiliation(s)
- S M Milligan
- Department of Zoology, Michigan State University, East Lansing 48824
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