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Viegas J. Profile of Wanderley de Souza. Proc Natl Acad Sci U S A 2024; 121:e2403579121. [PMID: 38621140 PMCID: PMC11046583 DOI: 10.1073/pnas.2403579121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024] Open
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Verdan R, Patricio B, Weismuller G, Miranda K, de Souza W, Benchimol M, Gadelha AP. Characterization of a new extra-axonemal structure in the Giardia intestinalis flagella. J Struct Biol 2024; 216:108064. [PMID: 38280689 DOI: 10.1016/j.jsb.2024.108064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 01/05/2024] [Accepted: 01/18/2024] [Indexed: 01/29/2024]
Abstract
The inner structure of the flagella of Giardia intestinalis is similar to that of other organisms, consisting of nine pairs of outer microtubules and a central pair containing radial spokes. Although the 9+2 axonemal structure is conserved, it is not clear whether subregions, including the transition zone, are present in the flagella of this parasite. Giardia axonemes originate from basal bodies and have a lengthy cytosolic portion before becoming active flagella. The region of the emergence of the flagellum is not accompanied by any membrane specialization, as seen in other protozoa. Although Giardia is an intriguing model of study, few works focused on the ultrastructural analysis of the flagella of this parasite. Here, we analyzed the externalization region of the G. intestinalis flagella using ultra-high resolution scanning microscopy (with electrons and ions), atomic force microscopy in liquid medium, freeze fracture, and electron tomography. Our data show that this region possesses a distinctive morphological feature - it extends outward and takes on a ring-like shape. When the plasma membrane is removed, a structure surrounding the axoneme becomes visible in this region. This new extra-axonemal structure is observed in all pairs of flagella of trophozoites and remains attached to the axoneme even when the interconnections between the axonemal microtubules are disrupted. High-resolution scanning electron microscopy provided insights into the arrangement of this structure, contributing to the characterization of the externalization region of the flagella of this parasite.
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Affiliation(s)
- Raphael Verdan
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Beatriz Patricio
- Instituto Biomédico, Universidade Federal do Estado Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Gilberto Weismuller
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Kildare Miranda
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil; Centro Nacional de Biologia Estrutural e Bioimagem e Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil; Centro Multiusuário para Análise de Fenômenos Biomédicos, Universidade do Estado do Amazonas, Manaus, Brazil
| | - Wanderley de Souza
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil; Centro Nacional de Biologia Estrutural e Bioimagem e Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil; Centro Multiusuário para Análise de Fenômenos Biomédicos, Universidade do Estado do Amazonas, Manaus, Brazil
| | - Marlene Benchimol
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil; Centro Nacional de Biologia Estrutural e Bioimagem e Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil; Universidade do Grande Rio (UNIGRANRIO), Rio de Janeiro, RJ, Brazil
| | - Ana Paula Gadelha
- Universidade do Grande Rio (UNIGRANRIO), Rio de Janeiro, RJ, Brazil; Diretoria de Metrologia Científica e Industrial, Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Rio de Janeiro, Rio de Janeiro, Brazil.
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Benchimol M, Gadelha AP, de Souza W. Unusual Cell Structures and Organelles in Giardia intestinalis and Trichomonas vaginalis Are Potential Drug Targets. Microorganisms 2022; 10:2176. [PMID: 36363768 PMCID: PMC9698047 DOI: 10.3390/microorganisms10112176] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 10/28/2022] [Accepted: 10/31/2022] [Indexed: 09/29/2023] Open
Abstract
This review presents the main cell organelles and structures of two important protist parasites, Giardia intestinalis, and Trichomonas vaginalis; many are unusual and are not found in other eukaryotic cells, thus could be good candidates for new drug targets aimed at improvement of the chemotherapy of diseases caused by these eukaryotic protists. For example, in Giardia, the ventral disc is a specific structure to this parasite and is fundamental for the adhesion and pathogenicity to the host. In Trichomonas, the hydrogenosome, a double membrane-bounded organelle that produces ATP, also can be a good target. Other structures include mitosomes, ribosomes, and proteasomes. Metronidazole is the most frequent compound used to kill many anaerobic organisms, including Giardia and Trichomonas. It enters the cell by passive diffusion and needs to find a highly reductive environment to be reduced to the nitro radicals to be active. However, it provokes several side effects, and some strains present metronidazole resistance. Therefore, to improve the quality of the chemotherapy against parasitic protozoa is important to invest in the development of highly specific compounds that interfere with key steps of essential metabolic pathways or in the functional macromolecular complexes which are most often associated with cell structures and organelles.
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Affiliation(s)
- Marlene Benchimol
- Laboratorio de Ultraestrutura Celular Hertha Meyer, Centro de Ciêcias da Saúde, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Cidade Universitaria, Rio de Janeiro 96200-000, Brazil
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, Brazil
- Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens e Centro Nacional de Biologia Estrutural e Bioimagens, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, Brazil
| | - Ana Paula Gadelha
- Diretoria de Metrologia Aplicada as Ciências da Vida, Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Rio de Janeiro 25250-020, Brazil
| | - Wanderley de Souza
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, Brazil
- Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens e Centro Nacional de Biologia Estrutural e Bioimagens, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, Brazil
- CMABio, Escola Superior de Saúde, Universidade do Estado do Amazonas-UEA, Manaus 69850-000, Brazil
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Nanoarchitecture of the ventral disc of Giardia intestinalis as revealed by high-resolution scanning electron microscopy and helium ion microscopy. Histochem Cell Biol 2022; 157:251-265. [DOI: 10.1007/s00418-021-02060-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2021] [Indexed: 12/21/2022]
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Steele-Ogus MC, Johnson RS, MacCoss MJ, Paredez AR. Identification of Actin Filament-Associated Proteins in Giardia lamblia. Microbiol Spectr 2021; 9:e0055821. [PMID: 34287056 PMCID: PMC8552679 DOI: 10.1128/spectrum.00558-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Accepted: 06/17/2021] [Indexed: 11/20/2022] Open
Abstract
The deep-branching protozoan parasite Giardia lamblia is the causative agent of the intestinal disease giardiasis. Consistent with its proposed evolutionary position, many pathways are minimalistic or divergent, including its actin cytoskeleton. Giardia is the only eukaryote known to lack all canonical actin-binding proteins. Previously, our lab identified a number of noncanonical Giardia lamblia actin (GlActin) interactors; however, these proteins appeared to interact only with monomeric or globular actin (G-actin) rather than with filamentous actin (F-actin). To identify F-actin interactors, we used a chemical cross-linker to preserve native interactions followed by an anti-GlActin antibody, protein A affinity chromatography, and liquid chromatography coupled to mass spectrometry. We found 46 putative actin interactors enriched under the conditions favoring F-actin. Data are available via ProteomeXchange with identifier PXD026067. None of the proteins identified contain known actin-interacting motifs, and many lacked conserved domains. Each potential interactor was then tagged with the fluorescent protein mNeonGreen and visualized in live cells. We categorized the proteins based on their primary localization; localizations included ventral disc, marginal plate, nuclei, flagella, plasma membrane, and internal membranes. One protein from each of the six categories was colocalized with GlActin using immunofluorescence microscopy. We also co-immunoprecipitated one protein from each category and confirmed three of the six potential interactions. Most of the localization patterns are consistent with previously demonstrated GlActin functions, but the ventral disc represents a new category of actin interactor localization. These results suggest a role for GlActin in ventral disc function, which has previously been controversial. IMPORTANCE Giardia lamblia is an intestinal parasite that colonizes the small intestine and causes diarrhea, which can lead to dehydration and malnutrition. Giardia actin (GlActin) has a conserved role in Giardia cells, despite being a highly divergent protein with none of the conserved regulators found in model organisms. Here, we identify and localize 46 interactors of polymerized actin. These putative interactors localize to a number of places in the cell, underlining GlActin's importance in multiple cellular processes. Surprisingly, eight of these proteins localize to the ventral disc, Giardia's host attachment organelle. Since host attachment is required for infection, proteins involved in this process are an appealing target for new drugs. While treatments for Giardia exist, drug resistance is becoming more common, resulting in a need for new treatments. Giardia and human systems are highly dissimilar, thus drugs specifically tailored to Giardia proteins would be less likely to have side effects.
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Affiliation(s)
| | - Richard S. Johnson
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - Michael J. MacCoss
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
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Chiriac AE, Azoicai D, Coroaba A, Doroftei F, Timpu D, Chiriac A, Pertea M, Ursu EL, Pinteala M. Raman Spectroscopy, X-ray Diffraction, and Scanning Electron Microscopy as Noninvasive Methods for Microstructural Alterations in Psoriatic Nails. Molecules 2021; 26:molecules26020280. [PMID: 33429943 PMCID: PMC7826832 DOI: 10.3390/molecules26020280] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/03/2021] [Accepted: 01/05/2021] [Indexed: 11/16/2022] Open
Abstract
Psoriasis is a chronic inflammatory disease associated with immune system dysfunction that can affect nails, with a negative impact on patient life quality. Usually, nail psoriasis is associated with skin psoriasis and is therefore relatively simple to diagnose. However, up to 10% of nail psoriasis occurs isolated and may be difficult to diagnose by means of current methods (nail biopsy, dermoscopy, video dermoscopy, capillaroscopy, ultrasound of the nails, etc.). Since the nail is a complex biological tissue, mainly composes of hard α-keratins, the structural and morphological techniques can be used to analyze the human fingernails. The aim of this study was to corroborate the information obtained using Raman spectroscopy with those obtained by scanning electron microscopy (SEM) and X-ray diffractometry and to assess the potential of these techniques as non-invasive dermatologic diagnostic tools and an alternative to current methods.
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Affiliation(s)
- Anca E. Chiriac
- Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iași, Romania; (A.E.C.); (D.A.); (M.P.)
| | - Doina Azoicai
- Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iași, Romania; (A.E.C.); (D.A.); (M.P.)
| | - Adina Coroaba
- Centre of Advanced Research in Bionanoconjugates and Biopolymers, “Petru Poni” Institute of Macromolecular Chemistry, 700487 Iași, Romania; (A.C.); (F.D.); (A.C.); (M.P.)
| | - Florica Doroftei
- Centre of Advanced Research in Bionanoconjugates and Biopolymers, “Petru Poni” Institute of Macromolecular Chemistry, 700487 Iași, Romania; (A.C.); (F.D.); (A.C.); (M.P.)
| | - Daniel Timpu
- Photochemistry and Polyaddition Department, “Petru Poni” Institute of Macromolecular Chemistry, 700487 Iași, Romania;
| | - Anca Chiriac
- Centre of Advanced Research in Bionanoconjugates and Biopolymers, “Petru Poni” Institute of Macromolecular Chemistry, 700487 Iași, Romania; (A.C.); (F.D.); (A.C.); (M.P.)
- Department of Dermatophysiology, “Apollonia” University, 700511 Iași, Romania
- Department of Dermatology, Nicolina Medical Center, 700613 Iași, Romania
| | - Mihaela Pertea
- Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iași, Romania; (A.E.C.); (D.A.); (M.P.)
- Clinic of Plastic and Reconstructive Microsurgery, “Sf. Spiridon” Emergency Hospital, 700111 Iași, Romania
| | - Elena-Laura Ursu
- Centre of Advanced Research in Bionanoconjugates and Biopolymers, “Petru Poni” Institute of Macromolecular Chemistry, 700487 Iași, Romania; (A.C.); (F.D.); (A.C.); (M.P.)
- Correspondence:
| | - Mariana Pinteala
- Centre of Advanced Research in Bionanoconjugates and Biopolymers, “Petru Poni” Institute of Macromolecular Chemistry, 700487 Iași, Romania; (A.C.); (F.D.); (A.C.); (M.P.)
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Schmidt M, Byrne JM, Maasilta IJ. Bio-imaging with the helium-ion microscope: A review. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2021; 12:1-23. [PMID: 33489663 PMCID: PMC7801799 DOI: 10.3762/bjnano.12.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 11/26/2020] [Indexed: 06/01/2023]
Abstract
Scanning helium-ion microscopy (HIM) is an imaging technique with sub-nanometre resolution and is a powerful tool to resolve some of the tiniest structures in biology. In many aspects, the HIM resembles a field-emission scanning electron microscope (FE-SEM), but the use of helium ions rather than electrons provides several advantages, including higher surface sensitivity, larger depth of field, and a straightforward charge-compensating electron flood gun, which enables imaging of non-conductive samples, rendering HIM a promising high-resolution imaging technique for biological samples. Starting with studies focused on medical research, the last decade has seen some particularly spectacular high-resolution images in studies focused on plants, microbiology, virology, and geomicrobiology. However, HIM is not just an imaging technique. The ability to use the instrument for milling biological objects as small as viruses offers unique opportunities which are not possible with more conventional focused ion beams, such as gallium. Several pioneering technical developments, such as methods to couple secondary ion mass spectrometry (SIMS) or ionoluminescence with the HIM, also offer the possibility for new and exciting research on biological materials. In this review, we present a comprehensive overview of almost all currently published literature which has demonstrated the application of HIM for imaging of biological specimens. We also discuss some technical features of this unique type of instrument and highlight some of the new advances which will likely become more widely used in the years to come.
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Affiliation(s)
- Matthias Schmidt
- Helmholtz-Centre for Environmental Research GmbH - UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - James M Byrne
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8 1RJ, United Kingdom
| | - Ilari J Maasilta
- Nanoscience Center, Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
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Mousley M, Möller W, Philipp P, Hlawacek G, Wirtz T, Eswara S. Structural and chemical evolution of Au-silica core-shell nanoparticles during 20 keV helium ion irradiation: a comparison between experiment and simulation. Sci Rep 2020; 10:12058. [PMID: 32694558 PMCID: PMC7374165 DOI: 10.1038/s41598-020-68955-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 06/26/2020] [Indexed: 11/29/2022] Open
Abstract
Au-silica core–shell nanoparticles have been irradiated with 20 keV He+ ions up to a maximum fluence of 4.7 × 1017 ions/cm2. The nanoscale structural and crystallographic evolution induced by He+ ion irradiation was followed at various stages using Transmission Electron Microscopy (TEM). During irradiation satellite Au clusters are formed around the main Au core, which remained crystalline even after the maximum He+ ion fluence. The spherical silica shell deformed into a hemisphere due to He+ ion irradiation. Three dimensional Monte-Carlo simulations, based on the binary collision approximation, have been performed on stacked infinite layers and an individual particle. The stacked layers results show that the He+ beam interacts with most of the nanoparticle and Au migrates in the direction of beam incidence agreeing with experimental findings. The individual particle results match the experiment in terms of the volume which is sputtered away however additional mechanisms, not included in the simulations, are present in the experiment during the satellite formation and silica shell deformation. These results show the ability for 20 keV He+ ions to be used for the modification of nanostructures. Furthermore, these results contribute to a quantitative understanding of the dynamic evolution of materials observed using microscopy techniques based on He+ ions.
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Affiliation(s)
- M Mousley
- Advanced Instrumentation for Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology, 41, rue du Brill, 4422, Belvaux, Luxembourg.
| | - W Möller
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf e.V., Bautzner Landstr. 400, 01328, Dresden, Germany
| | - P Philipp
- Advanced Instrumentation for Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology, 41, rue du Brill, 4422, Belvaux, Luxembourg
| | - G Hlawacek
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf e.V., Bautzner Landstr. 400, 01328, Dresden, Germany
| | - T Wirtz
- Advanced Instrumentation for Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology, 41, rue du Brill, 4422, Belvaux, Luxembourg
| | - S Eswara
- Advanced Instrumentation for Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology, 41, rue du Brill, 4422, Belvaux, Luxembourg
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Abstract
Giardia intestinalis, the causative agent of giardiasis, has complex cytoskeleton organization with structures involved in motility, adhesion, cell division, and cell differentiation. Microtubules are key components of the cytoskeleton and are the main elements of the ventral disc, median body, funis, in addition to four pairs of flagella. These cytoskeletal elements are basically stable microtubule arrangements. Although tubulins are the main proteins of these elements, molecular and biochemical analyses of Giardia trophozoites have revealed the presence of several new and not yet characterized proteins in these structures, which may contribute to their nanoarchitecture (mainly in the ventral disc). Despite these findings, morphological data are still required for understanding the organization and biogenesis of the cytoskeletal structures. In the study of this complex and specialized network of filaments in Giardia, two distinct and complementary approaches have been used in recent years: (a) transmission electron microscopy tomography of conventionally processed as well as cryo-fixed samples and (b) high-resolution scanning electron microscopy and helium ion microscopy in combination with new plasma membrane extraction protocols. In this review we include the most recent studies that have allowed better understanding of new Giardia components and their association with other filamentous structures of this parasite, thus providing new insights in the role of the cytoskeletal structures and their function in Giardia trophozoites.
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Wirtz T, De Castro O, Audinot JN, Philipp P. Imaging and Analytics on the Helium Ion Microscope. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2019; 12:523-543. [PMID: 30699036 DOI: 10.1146/annurev-anchem-061318-115457] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The helium ion microscope (HIM) has emerged as an instrument of choice for patterning, imaging and, more recently, analytics at the nanoscale. Here, we review secondary electron imaging on the HIM and the various methodologies and hardware components that have been developed to confer analytical capabilities to the HIM. Secondary electron-based imaging can be performed at resolutions down to 0.5 nm with high contrast, with high depth of field, and directly on insulating samples. Analytical methods include secondary electron hyperspectral imaging (SEHI), scanning transmission ion microscopy (STIM), backscattering spectrometry and, in particular, secondary ion mass spectrometry (SIMS). The SIMS system that was specifically designed for the HIM allows the detection of all elements, the differentiation between isotopes, and the detection of trace elements. It provides mass spectra, depth profiles, and 2D or 3D images with lateral resolutions down to 10 nm.
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Affiliation(s)
- Tom Wirtz
- Advanced Instrumentation for Ion Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology (LIST), L-4422 Belvaux, Luxembourg;
| | - Olivier De Castro
- Advanced Instrumentation for Ion Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology (LIST), L-4422 Belvaux, Luxembourg;
| | - Jean-Nicolas Audinot
- Advanced Instrumentation for Ion Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology (LIST), L-4422 Belvaux, Luxembourg;
| | - Patrick Philipp
- Advanced Instrumentation for Ion Nano-Analytics (AINA), MRT Department, Luxembourg Institute of Science and Technology (LIST), L-4422 Belvaux, Luxembourg;
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New advances in scanning microscopy and its application to study parasitic protozoa. Exp Parasitol 2018; 190:10-33. [PMID: 29702111 DOI: 10.1016/j.exppara.2018.04.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 04/10/2018] [Accepted: 04/23/2018] [Indexed: 12/31/2022]
Abstract
Scanning electron microscopy has been used to observe and study parasitic protozoa for at least 40 years. However, field emission electron sources, as well as improvements in lenses and detectors, brought the resolution power of scanning electron microscopes (SEM) to a new level. Parallel to the refinement of instruments, protocols for preservation of the ultrastructure, immunolabeling, exposure of cytoskeleton and inner structures of parasites and host cells were developed. This review is focused on protozoan parasites of medical and veterinary relevance, e.g., Toxoplasma gondii, Tritrichomonas foetus, Giardia intestinalis, and Trypanosoma cruzi, compilating the main achievements in describing the fine ultrastructure of their surface, cytoskeleton and interaction with host cells. Two new resources, namely, Helium Ion Microscopy (HIM) and Slice and View, using either Focused Ion Beam (FIB) abrasion or Microtome Serial Sectioning (MSS) within the microscope chamber, combined to backscattered electron imaging of fixed (chemically or by quick freezing followed by freeze substitution and resin embedded samples is bringing an exponential amount of valuable information. In HIM there is no need of conductive coating and the depth of field is much higher than in any field emission SEM. As for FIB- and MSS-SEM, high resolution 3-D models of areas and volumes larger than any other technique allows can be obtained. The main results achieved with all these technological tools and some protocols for sample preparation are included in this review. In addition, we included some results obtained with environmental/low vacuum scanning microscopy and cryo-scanning electron microscopy, both promising, but not yet largely employed SEM modalities.
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Pinteala T, Chiriac AE, Rosca I, Larese Filon F, Pinteala M, Chiriac A, Podoleanu C, Stolnicu S, Coros MF, Coroaba A. Nail Damage (Severe Onychodystrophy) Induced by Acrylate Glue: Scanning Electron Microscopy and Energy Dispersive X-Ray Investigations. Skin Appendage Disord 2016; 2:137-142. [PMID: 28232921 DOI: 10.1159/000450791] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 09/13/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) techniques have been used in various fields of medical research, including different pathologies of the nails; however, no studies have focused on obtaining high-resolution microscopic images and elemental analysis of disorders caused by synthetic nails and acrylic adhesives. METHODS Damaged/injured fingernails caused by the use of acrylate glue and synthetic nails were investigated using SEM and EDX methods. RESULTS SEM and EDX proved that synthetic nails, acrylic glue, and nails damaged by contact with acrylate glue have a different morphology and different composition compared to healthy human nails. CONCLUSIONS SEM and EDX analysis can give useful information about the aspects of topography (surface sample), morphology (shape and size), hardness or reflectivity, and the elemental composition of nails.
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Affiliation(s)
- Tudor Pinteala
- Grigore T. Popa University of Medicine and Pharmacy, Iasi, Romania
| | | | - Irina Rosca
- Centre of Advanced Research in Bionanoconjugates and Biopolymers, Institute of Macromolecular Chemistry Petru Poni, Iasi, Romania
| | - Francesca Larese Filon
- Dipartimento di Scienze di Medicina Pubblica, Università degli Studi di Trieste, Trieste, Italy
| | - Mariana Pinteala
- Centre of Advanced Research in Bionanoconjugates and Biopolymers, Institute of Macromolecular Chemistry Petru Poni, Iasi, Romania
| | - Anca Chiriac
- Department of Dermatology, Nicolina Medical Center, Iasi, Romania; Department of Dermato-Physiology, Apollonia University, Iasi, Romania
| | - Cristian Podoleanu
- Cardiology Clinic, University of Medicine and Pharmacy of Targu-Mures, Tîrgu Mureș, Romania
| | - Simona Stolnicu
- Pathology Department, University of Medicine and Pharmacy of Targu-Mures, Tîrgu Mureș, Romania
| | - Marius Florin Coros
- Surgery Department, University of Medicine and Pharmacy of Targu-Mures, Tîrgu Mureș, Romania
| | - Adina Coroaba
- Centre of Advanced Research in Bionanoconjugates and Biopolymers, Institute of Macromolecular Chemistry Petru Poni, Iasi, Romania
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de Souza W, Attias M. New views of the Toxoplasma gondii parasitophorous vacuole as revealed by Helium Ion Microscopy (HIM). J Struct Biol 2015; 191:76-85. [PMID: 26004092 DOI: 10.1016/j.jsb.2015.05.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 05/13/2015] [Accepted: 05/14/2015] [Indexed: 11/27/2022]
Abstract
The Helium Ion Microscope (HIM) is a new technology that uses a highly focused helium ion beam to scan and interact with the sample, which is not coated. The images have resolution and depth of field superior to field emission scanning electron microscopes. In this paper, we used HIM to study LLC-MK2 cells infected with Toxoplasma gondii. These samples were chemically fixed and, after critical point drying, were scraped with adhesive tape to expose the inner structure of the cell and parasitophorous vacuoles. We confirmed some of the previous findings made by field emission-scanning electron microscopy and showed that the surface of the parasite is rich in structures suggestive of secretion, that the nanotubules of the intravacuolar network (IVN) are not always straight, and that bifurcations are less frequent than previously thought. Fusion of the tubules with the parasite membrane or the parasitophorous vacuole membrane (PVM) was also infrequent. Tiny adhesive links were observed for the first time connecting the IVN tubules. The PVM showed openings of various sizes that even allowed the observation of endoplasmic reticulum membranes in the cytoplasm of the host cell. These findings are discussed in relation to current knowledge on the cell biology of T. gondii.
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Affiliation(s)
- Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Centro de Ciências da Saúde, Bloco G, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil; Instituto Nacional de Biologia Estrutural e Biomagem-INBEB, and Centro Nacional de Biologia Estrutural e Biomagem-CENABIO, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Instituto Nacional de Metrologia, Qualidade e Tecnologia-INMETRO, Duque de Caxias, RJ, Brazil
| | - Marcia Attias
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Centro de Ciências da Saúde, Bloco G, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil; Instituto Nacional de Biologia Estrutural e Biomagem-INBEB, and Centro Nacional de Biologia Estrutural e Biomagem-CENABIO, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
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