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Pandey M, Sarkar S, Ghosh SK. Ancestral TALE homeobox protein transcription factor regulates actin dynamics and cellular activities of protozoan parasite Entamoeba invadens. Mol Microbiol 2024. [PMID: 38654540 DOI: 10.1111/mmi.15266] [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: 06/30/2023] [Revised: 04/05/2024] [Accepted: 04/10/2024] [Indexed: 04/26/2024]
Abstract
Entamoeba histolytica causes invasive amoebiasis, an important neglected tropical disease with a significant global health impact. The pathogenicity and survival of E. histolytica and its reptilian equivalent, Entamoeba invadens, relies on its ability to exhibit efficient motility, evade host immune responses, and exploit host resources, all of which are governed by the actin cytoskeleton remodeling. Our study demonstrates the early origin and the regulatory role of TALE homeobox protein EiHbox1 in actin-related cellular processes. Several genes involved in different biological pathways, including actin dynamics are differentially expressed in EiHbox1 silenced cells. EiHbox1 silenced parasites showed disrupted F-actin organization and loss of cellular polarity. EiHbox1's presence in the anterior region of migrating cells further suggests its involvement in maintaining cellular polarity. Loss of polarized morphology of EiHbox1 silenced parasites leads to altered motility from fast, directionally persistent, and highly chemotactic to slow, random, and less chemotactic, which subsequently leads to defective aggregation during encystation. EiHbox1 knockdown also resulted in a significant reduction in phagocytic capacity and poor capping response. These findings highlight the importance of EiHbox1 of E. invadens in governing cellular processes crucial for their survival, pathogenicity, and evasion of the host immune system.
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Affiliation(s)
- Meenakshi Pandey
- Department of Bioscience and Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, India
| | - Shilpa Sarkar
- Department of Bioscience and Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, India
| | - Sudip K Ghosh
- Department of Bioscience and Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, India
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2
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Bosch DE, Jeck WR, Siderovski DP. Self-activating G protein α subunits engage seven-transmembrane Regulator of G protein Signaling (RGS) proteins and a Rho guanine nucleotide exchange factor effector in the amoeba Naegleria fowleri. J Biol Chem 2022; 298:102167. [PMID: 35738399 PMCID: PMC9283941 DOI: 10.1016/j.jbc.2022.102167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 06/15/2022] [Accepted: 06/16/2022] [Indexed: 11/17/2022] Open
Abstract
The free-living amoeba Naegleria fowleri is a causative agent of primary amoebic meningoencephalitis and is highly resistant to current therapies, resulting in mortality rates >97%. As many therapeutics target G protein-centered signal transduction pathways, further understanding the functional significance of G protein signaling within N. fowleri should aid future drug discovery against this pathogen. Here, we report that the N. fowleri genome encodes numerous transcribed G protein signaling components, including G protein-coupled receptors (GPCRs), heterotrimeric G protein subunits, Regulator of G protein Signaling (RGS) proteins, and candidate Gα effector proteins. We found N. fowleri Gα subunits have diverse nucleotide cycling kinetics; Nf Gα5 and Gα7 exhibit more rapid nucleotide exchange than GTP hydrolysis (i.e. "self-activating" behavior). A crystal structure of Nf Gα7 highlights the stability of its nucleotide-free state, consistent with its rapid nucleotide exchange. Variations in the phosphate binding loop (P-loop) also contribute to nucleotide cycling differences among Gα subunits. Similar to plant G protein signaling pathways, N. fowleri Gα subunits selectively engage members of a large seven-transmembrane RGS protein family, resulting in acceleration of GTP hydrolysis. We show Nf Gα2 and Gα3 directly interact with a candidate Gα effector protein, RGS-RhoGEF, similar to mammalian Gα12/13 signaling pathways. We demonstrate Nf Gα2 and Gα3 each engage RGS-RhoGEF through a canonical Gα/RGS domain interface, suggesting a shared evolutionary origin with G protein signaling in the enteric pathogen Entamoeba histolytica. These findings further illuminate the evolution of G protein signaling and identify potential targets of pharmacological manipulation in Naegleria fowleri.
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Affiliation(s)
- Dustin E Bosch
- Department of Pathology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA.
| | - William R Jeck
- Department of Pathology, Duke University School of Medicine, Durham, North Carolina, USA
| | - David P Siderovski
- Department of Pharmacology & Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
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3
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Fang N, Tang D, Zhang H, Zeng J. Smooth muscle actin immunostain is useful for the diagnosis of Trichomonas vaginalis in vaginal smears. Diagn Cytopathol 2021; 49:1052-1055. [PMID: 34291890 DOI: 10.1002/dc.24822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 06/01/2021] [Accepted: 06/07/2021] [Indexed: 11/07/2022]
Abstract
OBJECTIVE The parasite Trichomonas vaginalis (T. vaginalis) causes one of the most common non-viral sexually transmitted infections in humans. T. vaginalis is notorious for its inconspicuous appearance in vaginal smears. It can be missed under the microscope. METHOD In the present study, we investigate the immunoreactivity of T. vaginalis to smooth muscle actin (SMA) in the vaginal smear. RESULT T. vaginalis trophozoite and pseduocyst are immunoreactive for SMA in all of the study group cases (n = 21) and in none of the control group cases (n = 21). Thus, SMA immunostain is a sensitive method for the demonstration of T. vaginalis. Moreover, the protozoan attains a conspicuous and unique appearance. By SMA immunohistochemical stain, the apperance of T. vaginalis floated freely or located in the cytoplasm of the epithelial cells is easily identified. CONCLUSION We recommend performing SMA immunostain in every vaginal smear with clinical or pathologic suspicion of trichomoniasis.
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Affiliation(s)
- Ni Fang
- Department of Pathology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Deng Tang
- Department of Pathology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Hanjie Zhang
- Department of Pathology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Jie Zeng
- Department of Medical Oncology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
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4
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Abstract
Bioimage analysis (BIA) has historically helped study how and why cells move; biological experiments evolved in intimate feedback with the most classical image processing techniques because they contribute objectivity and reproducibility to an eminently qualitative science. Cell segmentation, tracking, and morphology descriptors are all discussed here. Using ameboid motility as a case study, these methods help us illustrate how proper quantification can augment biological data, for example, by choosing mathematical representations that amplify initially subtle differences, by statistically uncovering general laws or by integrating physical insight. More recently, the non-invasive nature of quantitative imaging is fertilizing two blooming fields: mechanobiology, where many biophysical measurements remain inaccessible, and microenvironments, where the quest for physiological relevance has exploded data size. From relief to remedy, this trend indicates that BIA is to become a main vector of biological discovery as human visual analysis struggles against ever more complex data.
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Affiliation(s)
- Aleix Boquet-Pujadas
- Institut Pasteur, Bioimage Analysis Unit, 25 rue du Dr. Roux, Paris Cedex 15 75724, France
- Centre National de la Recherche Scientifique, CNRS UMR3691, Paris, France
- Sorbonne Université, Paris 75005, France
| | - Jean-Christophe Olivo-Marin
- Institut Pasteur, Bioimage Analysis Unit, 25 rue du Dr. Roux, Paris Cedex 15 75724, France
- Centre National de la Recherche Scientifique, CNRS UMR3691, Paris, France
| | - Nancy Guillén
- Institut Pasteur, Bioimage Analysis Unit, 25 rue du Dr. Roux, Paris Cedex 15 75724, France
- Centre National de la Recherche Scientifique, CNRS ERL9195, Paris, France
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Morphological and Motility Features of the Stable Bleb-Driven Monopodial Form of Entamoeba and Its Importance in Encystation. Infect Immun 2020; 88:IAI.00903-19. [PMID: 32393510 DOI: 10.1128/iai.00903-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 04/27/2020] [Indexed: 11/20/2022] Open
Abstract
Entamoeba histolytica and its reptilian counterpart and encystation model Entamoeba invadens formed a polarized monopodial morphology when treated with pentoxifylline. This morphology was propelled by retrograde flow of the cell surface resulting from a cyclic sol-gel conversion of cytoplasm and a stable bleb at the leading edge. Pentoxifylline treatment switched the unpolarized, adherent trophozoites to the nonadherent, stable bleb-driven form and altered the motility pattern from slow and random to fast, directionally persistent, and highly chemotactic. Interestingly, exogenously added adenosine produced multiple protrusions and random motility, an opposite phenotype to that of pentoxifylline. Thus, pentoxifylline, an adenosine antagonist, may be inducing the monopodial morphology by preventing lateral protrusions and restricting the leading edge to one site. The polarized form of E. invadens was aggregation competent, and time-lapse microscopy of encystation revealed its appearance during early hours, mediating the cell aggregation by directional cell migration. The addition of purine nucleotides to in vitro encystation culture prevented the formation of polarized morphology and inhibited the cell aggregation and, thus, the encystation, which further showed the importance of the polarized form in the Entamoeba life cycle. Cell polarity and motility are essential in the pathogenesis of Entamoeba parasites, and the stable bleb-driven polarized morphology of Entamoeba may also be important in invasive amoebiasis.
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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.
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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
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Talamás-Lara D, Rosales-Encina JL, Chávez-Munguía B, Acosta-Virgen K, Hernández-Ramírez VI, Salazar-Villatoro L, Espinosa-Cantellano M, Martínez-Palomo A, Talamás-Rohana P. Entamoeba histolytica and Entamoeba dispar: Morphological and Behavioral Differences Induced by Fibronectin through GTPases Activation and Actin-Binding Proteins. J Eukaryot Microbiol 2020; 67:491-504. [PMID: 32302033 DOI: 10.1111/jeu.12797] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 02/19/2020] [Accepted: 03/26/2020] [Indexed: 01/09/2023]
Abstract
Early steps of tissue invasion by Entamoeba histolytica are mediated by adhesion and migration through matrix components such as fibronectin with the participation of the actin cytoskeleton. Striking differences in their produced structures, movement, and migration were found. These observations suggest differential changes in their ability to organize the actin cytoskeleton and, therefore, to modify its morphology after adhesion to fibronectin. To understand these observations, we explore deeper the cytoskeleton pathway of E. histolytica compared to Entamoeba dispar, analyzing the activation and involvement of actin cytoskeleton regulatory proteins such as small GTPases (Rho, Rac1 and Cdc42), myosin IB, paxillin, alpha-actinin, and ARP2/3 during interaction with fibronectin. Results showed a higher activation of Rac1 in E. histolytica compared to E. dispar, while Cdc42 and RhoA were equally activated in both amebae; besides, variations in the amount of myosin IB, paxillin, and ARP2/3 were detected among these species, coinciding and reflected in formation of lamellipodia in E. histolytica and filopodia in E. dispar. These could partially explain the higher invasive capacity of E. histolytica compared to E. dispar, due to its pleomorphic ability, high motility, migration, activation, and abundance of proteins involved in the cytoskeleton arrangement.
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Affiliation(s)
- Daniel Talamás-Lara
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal, 07360, Mexico City, Mexico
| | - José Luis Rosales-Encina
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal, 07360, Mexico City, Mexico
| | - Bibiana Chávez-Munguía
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal, 07360, Mexico City, Mexico
| | - Karla Acosta-Virgen
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal, 07360, Mexico City, Mexico
| | - Verónica Ivonne Hernández-Ramírez
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal, 07360, Mexico City, Mexico
| | - Lizbeth Salazar-Villatoro
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal, 07360, Mexico City, Mexico
| | - Martha Espinosa-Cantellano
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal, 07360, Mexico City, Mexico
| | - Adolfo Martínez-Palomo
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal, 07360, Mexico City, Mexico
| | - Patricia Talamás-Rohana
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal, 07360, Mexico City, Mexico
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8
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Guillén N. The interaction betweenEntamoeba histolyticaand enterobacteria shed light on an ancient antibacterial response. Cell Microbiol 2019; 21:e13039. [DOI: 10.1111/cmi.13039] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 04/17/2019] [Accepted: 04/30/2019] [Indexed: 01/27/2023]
Affiliation(s)
- Nancy Guillén
- Institut Pasteur Paris France
- INSBCentre National de la Recherche Scientifique, CNRS‐ERL9195 Paris France
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9
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Mechanisms of natural resistance of Balb/c mice to experimental liver amoebiasis. Biosci Rep 2019; 39:BSR20182333. [PMID: 30979831 PMCID: PMC6500896 DOI: 10.1042/bsr20182333] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 04/03/2019] [Accepted: 04/10/2019] [Indexed: 11/24/2022] Open
Abstract
Entamoeba histolytica is the parasite responsible for human amoebiasis. The analysis of the natural resistance mechanisms of some rodents to amoebic liver abscess (ALA) may reveal alternative pathogenicity mechanisms to those previously discovered in the experimental model of ALA in hamsters. In this work the natural resistance of BALB/c mice to ALA was explored by performing: (i) in vivo chemotaxis analysis with a specifically designed chamber; (ii) in vitro amoebic survival in fresh and decomplemented serum; (iii) histological temporal course analysis of ALA development in mice with different treatments (hypocomplementemic, hyperimmune and treated with iNOS and NADPH oxidase inhibitors) and (iv) mouse liver amoebic infection by both in situ implantation of ALA from hamsters and inoculation of parasites into the peritoneal cavity. The results show that E. histolytica clearance from the mouse liver is related to a low chemotactic activity of complement, which results in poor inflammatory response and parasite inability to cause tissue damage. Also, the absence of amoebic tropism for the mouse liver is correlated with resistance to experimental liver amoebiasis.
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10
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Klughammer N, Bischof J, Schnellbächer ND, Callegari A, Lénárt P, Schwarz US. Cytoplasmic flows in starfish oocytes are fully determined by cortical contractions. PLoS Comput Biol 2018; 14:e1006588. [PMID: 30439934 PMCID: PMC6264906 DOI: 10.1371/journal.pcbi.1006588] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 11/29/2018] [Accepted: 10/22/2018] [Indexed: 11/19/2022] Open
Abstract
Cytoplasmic flows are an ubiquitous feature of biological systems, in particular in large cells, such as oocytes and eggs in early animal development. Here we show that cytoplasmic flows in starfish oocytes, which can be imaged well with transmission light microscopy, are fully determined by the cortical dynamics during surface contraction waves. We first show that the dynamics of the oocyte surface is highly symmetric around the animal-vegetal axis. We then mathematically solve the Stokes equation for flows inside a deforming sphere using the measured surface displacements as boundary conditions. Our theoretical predictions agree very well with the intracellular flows quantified by particle image velocimetry, proving that during this stage the starfish cytoplasm behaves as a simple Newtonian fluid on the micrometer scale. We calculate the pressure field inside the oocyte and find that its gradient is too small as to explain polar body extrusion, in contrast to earlier suggestions. Myosin II inhibition by blebbistatin confirms this conclusion, because it diminishes cell shape changes and hydrodynamic flow, but does not abolish polar body formation. As already noted by Aristotle, life is motion. On the molecular scale, thermal motion leads to diffusive transport. On cellular scales, however, diffusion starts to become inefficient, due to the general property of random walks that their spatial excursions grow less than linear with time. Therefore more directed transport processes are needed on cellular scales, including transport by molecular motors or by hydrodynamic flows. This is especially true for oocytes and eggs in early animal development, which often have to be large in order to store sufficient amounts of nutrients. Here we use starfish oocytes as a convenient model system to investigate the nature and function of cytoplasmic flows in early development. These cells are very large and optically transparent, and therefore ideal for live cell imaging that here we combine with image processing and mathematical modelling. This approach allows us to demonstrate that the experimentally observed cytoplasmic flows during early development are a direct consequence of surface contraction waves that deform the soft and contractile eggs. Additionally we show that despite its microscopic complexity, the cytoplasm behaves like a Newtonian fluid on the cellular scale. Our findings impose strong physical limits on the potential biological function of these flows and suggest that also other cellular systems that are soft and contractile might experience large cytoplasmic flows upon cell shape changes, for example during cell migration or division.
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Affiliation(s)
- Nils Klughammer
- Institute for Theoretical Physics and BioQuant, Heidelberg University, Heidelberg, Germany
| | - Johanna Bischof
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | | | - Andrea Callegari
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Péter Lénárt
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Ulrich S. Schwarz
- Institute for Theoretical Physics and BioQuant, Heidelberg University, Heidelberg, Germany
- * E-mail:
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11
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Manich M, Hernandez-Cuevas N, Ospina-Villa JD, Syan S, Marchat LA, Olivo-Marin JC, Guillén N. Morphodynamics of the Actin-Rich Cytoskeleton in Entamoeba histolytica. Front Cell Infect Microbiol 2018; 8:179. [PMID: 29896453 PMCID: PMC5986921 DOI: 10.3389/fcimb.2018.00179] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 05/09/2018] [Indexed: 02/01/2023] Open
Abstract
Entamoeba histolytica is the anaerobic protozoan parasite responsible for human amoebiasis, the third most deadly parasitic disease worldwide. This highly motile eukaryotic cell invades human tissues and constitutes an excellent experimental model of cell motility and cell shape deformation. The absence of extranuclear microtubules in Entamoeba histolytica means that the actin-rich cytoskeleton takes on a crucial role in not only amoebic motility but also other processes sustaining pathogenesis, such as the phagocytosis of human cells and the parasite's resistance of host immune responses. Actin is highly conserved among eukaryotes, although diverse isoforms exist in almost all organisms studied to date. However, E. histolytica has a single actin protein, the structure of which differs significantly from those of its human homologs. Here, we studied the expression, structure and dynamics of actin in E. histolytica. We used molecular and cellular approaches to evaluate actin gene expression during intestinal invasion by E. histolytica trophozoites. Based on a three-dimensional structural bioinformatics analysis, we characterized protein domains differences between amoebic actin and human actin. Fine-tuned molecular dynamics simulations enabled us to examine protein motion and refine the three-dimensional structures of both actins, including elements potentially accounting for differences changes in the affinity properties of amoebic actin and deoxyribonuclease I. The dynamic, multifunctional nature of the amoebic cytoskeleton prompted us to examine the pleiotropic forms of actin structures within live E. histolytica cells; we observed the cortical cytoskeleton, stress fibers, "dot-like" structures, adhesion plates, and macropinosomes. In line with these data, a proteomics study of actin-binding proteins highlighted the Arp2/3 protein complex as a crucial element for the development of macropinosomes and adhesion plaques.
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Affiliation(s)
- Maria Manich
- BioImaging Unit, Institut Pasteur, Paris, France.,Cell Biology of Parasitism Unit, Institut Pasteur, Paris, France
| | | | - Juan D Ospina-Villa
- Instituto Politécnico Nacional, Escuela Nacional de Medicina y Homeopatía, Mexico City, Mexico
| | - Sylvie Syan
- Cell Biology of Parasitism Unit, Institut Pasteur, Paris, France
| | - Laurence A Marchat
- Instituto Politécnico Nacional, Escuela Nacional de Medicina y Homeopatía, Mexico City, Mexico
| | | | - Nancy Guillén
- Cell Biology of Parasitism Unit, Institut Pasteur, Paris, France.,Centre National de la Recherche Scientifique, CNRS-ERL9195, Paris, France
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12
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Abstract
The protozoan parasite Entamoeba histolytica is the microbial agent of amoebiasis - an infection that is endemic worldwide and is associated with high morbidity and mortality rates. As the disease develops, virulent E. histolytica deplete the mucus layer, interact with the intestinal epithelium, and then degrade the colonic mucosa and disrupt the extracellular matrix (ECM). Our research demonstrated that virulent parasites with an invasive phenotype display rapid, highly specific changes in their transcriptome (notably for essential factors involved in carbohydrate metabolism and the processing of glycosylated residues). Moreover, combined activation of parasite and host lytic enzymes leads to the destruction of the intestinal parenchyma. Together, these enzymes degrade the mucus layer and the ECM, and trigger the inflammatory response essential to the development of amoebiasis.
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13
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Boquet-Pujadas A, Lecomte T, Manich M, Thibeaux R, Labruyère E, Guillén N, Olivo-Marin JC, Dufour AC. BioFlow: a non-invasive, image-based method to measure speed, pressure and forces inside living cells. Sci Rep 2017; 7:9178. [PMID: 28835648 PMCID: PMC5569094 DOI: 10.1038/s41598-017-09240-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 07/19/2017] [Indexed: 12/23/2022] Open
Abstract
Cell motility is governed by a complex molecular machinery that converts physico-chemical cues into whole-cell movement. Understanding the underlying biophysical mechanisms requires the ability to measure physical quantities inside the cell in a simple, reproducible and preferably non-invasive manner. To this end, we developed BioFlow, a computational mechano-imaging method and associated software able to extract intracellular measurements including pressure, forces and velocity everywhere inside freely moving cells in two and three dimensions with high spatial resolution in a non-invasive manner. This is achieved by extracting the motion of intracellular material observed using fluorescence microscopy, while simultaneously inferring the parameters of a given theoretical model of the cell interior. We illustrate the power of BioFlow in the context of amoeboid cell migration, by modelling the intracellular actin bulk flow of the parasite Entamoeba histolytica using fluid dynamics, and report unique experimental measures that complement and extend both theoretical estimations and invasive experimental measures. Thanks to its flexibility, BioFlow is easily adaptable to other theoretical models of the cell, and alleviates the need for complex or invasive experimental conditions, thus constituting a powerful tool-kit for mechano-biology studies. BioFlow is open-source and freely available via the Icy software.
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Affiliation(s)
- Aleix Boquet-Pujadas
- Institut Pasteur, Bioimage Analysis Unit, Paris, France.,CNRS UMR3691, Paris, France
| | - Timothée Lecomte
- Institut Pasteur, Bioimage Analysis Unit, Paris, France.,CNRS UMR3691, Paris, France
| | - Maria Manich
- Institut Pasteur, Bioimage Analysis Unit, Paris, France.,CNRS UMR3691, Paris, France
| | - Roman Thibeaux
- Institut Pasteur, Cell Biology of Parasitism Unit, Paris, France.,INSERM U786, Paris, France.,Institut Pasteur, Leptospirosis Research Unit, New Caledonia
| | - Elisabeth Labruyère
- Institut Pasteur, Bioimage Analysis Unit, Paris, France.,CNRS UMR3691, Paris, France
| | - Nancy Guillén
- Institut Pasteur, Cell Biology of Parasitism Unit, Paris, France.,INSERM U786, Paris, France.,CNRS ERL9195, Paris, France
| | | | - Alexandre C Dufour
- Institut Pasteur, Bioimage Analysis Unit, Paris, France. .,CNRS UMR3691, Paris, France.
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14
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Huth S, Reverey JF, Leippe M, Selhuber-Unkel C. Adhesion forces and mechanics in mannose-mediated acanthamoeba interactions. PLoS One 2017; 12:e0176207. [PMID: 28472161 PMCID: PMC5417443 DOI: 10.1371/journal.pone.0176207] [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: 01/06/2017] [Accepted: 04/06/2017] [Indexed: 12/15/2022] Open
Abstract
The human pathogenic amoeba Acanthamoeba castellanii (A. castellanii) causes severe diseases, including acanthamoeba keratitis and encephalitis. Pathogenicity arises from the killing of target-cells by an extracellular killing mechanism, where the crucial first step is the formation of a close contact between A. castellanii and the target-cell. This process is mediated by the glycocalix of the target-cell and mannose has been identified as key mediator. The aim of the present study was to carry out a detailed biophysical investigation of mannose-mediated adhesion of A. castellanii using force spectroscopy on single trophozoites. In detail, we studied the interaction of a mannose-coated cantilever with an A. castellanii trophozoite, as mannose is the decisive part of the cellular glycocalix in mediating pathogenicity. We observed a clear increase of the force to initiate cantilever detachment from the trophozoite with increasing contact time. This increase is also associated with an increase in the work of detachment. Furthermore, we also analyzed single rupture events during the detachment process and found that single rupture processes are associated with membrane tether formation, suggesting that the cytoskeleton is not involved in mannose binding events during the first few seconds of contact. Our study provides an experimental and conceptual basis for measuring interactions between pathogens and target-cells at different levels of complexity and as a function of interaction time, thus leading to new insights into the biophysical mechanisms of parasite pathogenicity.
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Affiliation(s)
- Steven Huth
- Institute of Materials Science, Biocompatible Nanomaterials, Christian-Albrechts-Universität zu Kiel, Kaiserstr. 2, D-24143 Kiel, Germany
| | - Julia F. Reverey
- Institute of Materials Science, Biocompatible Nanomaterials, Christian-Albrechts-Universität zu Kiel, Kaiserstr. 2, D-24143 Kiel, Germany
| | - Matthias Leippe
- Zoological Institute, Comparative Immunobiology, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, 24118 Kiel, Germany
| | - Christine Selhuber-Unkel
- Institute of Materials Science, Biocompatible Nanomaterials, Christian-Albrechts-Universität zu Kiel, Kaiserstr. 2, D-24143 Kiel, Germany
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15
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The motility of Entamoeba histolytica: finding ways to understand intestinal amoebiasis. Curr Opin Microbiol 2016; 34:24-30. [PMID: 27497052 DOI: 10.1016/j.mib.2016.07.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 07/21/2016] [Accepted: 07/25/2016] [Indexed: 12/16/2022]
Abstract
The pathogenic amoeba Entamoeba histolytica is able to migrate within various compartments of the human body. The present article reviews progress in understanding the mechanisms of cell motility in E. histolytica during human intestinal invasion and, in particular, how the three-dimensional characteristics of the environment regulate the parasite's behaviour. The amoeboid mode of migration that applies to E. histolytica's displacements on two-dimensional surfaces is also expected to apply to the three-dimensional environment in the human intestine although several unknown, distinct modalities may be involved. Recent advances in the field of tissue engineering have provided clues on how the construction of a human colon model could help us to understand the host's intestinal physiology and its changes following amoebic infection.
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16
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Tyrosine phosphorylation/dephosphorylation of myosin II essential light chains of Entamoeba histolytica trophozoites regulates their motility. Mol Biochem Parasitol 2016; 208:49-55. [PMID: 27318258 DOI: 10.1016/j.molbiopara.2016.05.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 05/03/2016] [Accepted: 05/10/2016] [Indexed: 11/22/2022]
Abstract
Entamoeba histolytica trophozoites dwell in the human intestine as comensals although under still unclear circumstances become invasive and destroy the host tissues. For these activities, trophozoites relay on remarkable motility provided by the cytoskeleton organization. Amebic actin and some of its actin-associated proteins are well known, while components of the myosin II molecule, although predicted from the E. histolytica genome, need biochemical and functional characterization. Recently, an amebic essential light myosin II chain, named EhMLCI, was identified and reported to be phosphorylated in tyrosines. The phosphorylated form of the protein was associated with the soluble assembly incompetent conformation of the heavy myosin chains, while the non-phosphorylated protein was identified with filamentous heavy chains, organized in an assembly competent conformation. It was postulated that EhMLCI tyrosine phosphorylation could act as a negative regulator of myosin II activity by its phosphorylation/dephosphorylation cycles. To test this hypothesis, we constructed an expression vector containing an EhMLCI DNA sequence where two tyrosine residues, with strong probability of phosphorylation and fall within the single EF-hand domain that interacts with the N-terminus of myosin II heavy chains, were replaced by phenylalanines. Transfected trophozoites, expressing the mutant MutEhMLCI protein cannot process it, thereby not incorporated into the phosphorylation/dephosphorylation cycles required for myosin II activity, results in motility defective trophozoites.
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