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Girard-Dias W, Augusto I, V. A. Fernandes T, G. Pascutti P, de Souza W, Miranda K. A spatially resolved elemental nanodomain organization within acidocalcisomes in Trypanosoma cruzi. Proc Natl Acad Sci U S A 2023; 120:e2300942120. [PMID: 37036984 PMCID: PMC10120040 DOI: 10.1073/pnas.2300942120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 03/06/2023] [Indexed: 04/12/2023] Open
Abstract
How are ions distributed in the three-dimensional (3D) volume confined in a nanoscale compartment? Regulation of ionic flow in the intracellular milieu has been explained by different theoretical models and experimentally demonstrated for several compartments with microscale dimensions. Most of these models predict a homogeneous distribution of ions seconds or milliseconds after an initial diffusion step formed at the ion translocation site, leaving open questions when it comes to ion/element distribution in spaces/compartments with nanoscale dimensions. Due to the influence of compartment size on the regulation of ionic flow, theoretical variations of classical models have been proposed, suggesting heterogeneous distributions of ions/elements within nanoscale compartments. Nonetheless, such assumptions have not been fully proven for the 3D volume of an organelle. In this work, we used a combination of cutting-edge electron microscopy techniques to map the 3D distribution of diffusible elements within the whole volume of acidocalcisomes in trypanosomes. Cryofixed cells were analyzed by scanning transmission electron microscopy tomography combined with elemental mapping using a high-performance setup of X-ray detectors. Results showed the existence of elemental nanodomains within the acidocalcisomes, where cationic elements display a self-excluding pattern. These were validated by Pearson correlation analysis and in silico molecular dynamic simulations. Formation of element domains within the 3D space of an organelle is demonstrated. Distribution patterns that support the electrodiffusion theory proposed for nanophysiology models have been found. The experimental pipeline shown here can be applied to a variety of models where ion mobilization plays a crucial role in physiological processes.
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Affiliation(s)
- Wendell Girard-Dias
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro21941-902, Brazil
- Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro21941-902, Brazil
- Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem - Universidade Federal do Rio de Janeiro, Rio de Janeiro21941-902, Brazil
- Plataforma de Microscopia Eletrônica Rudolf Barth, Instituto Oswaldo Cruz - Fiocruz, Rio de Janeiro21041-250, Brazil
| | - Ingrid Augusto
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro21941-902, Brazil
- Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro21941-902, Brazil
- Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem - Universidade Federal do Rio de Janeiro, Rio de Janeiro21941-902, Brazil
| | - Tácio V. A. Fernandes
- Laboratório de Modelagem e Dinâmica Molecular, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro21941-902, Brazil
- Instituto de Tecnologia de Fármacos (Farmanguinhos), Fiocruz, Rio de Janeiro22775-903, Brazil
| | - Pedro G. Pascutti
- Laboratório de Modelagem e Dinâmica Molecular, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro21941-902, Brazil
| | - Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro21941-902, Brazil
- Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro21941-902, Brazil
- Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem - Universidade Federal do Rio de Janeiro, Rio de Janeiro21941-902, Brazil
- Centro Multiusuário para Análise de Fenômenos Biomédicos, Universidade do Estado do Amazonas, Amazonas69065-001, Brazil
| | - Kildare Miranda
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro21941-902, Brazil
- Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro21941-902, Brazil
- Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem - Universidade Federal do Rio de Janeiro, Rio de Janeiro21941-902, Brazil
- Centro Multiusuário para Análise de Fenômenos Biomédicos, Universidade do Estado do Amazonas, Amazonas69065-001, Brazil
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Barreto-Vieira DF, da Silva MAN, Garcia CC, Miranda MD, Matos ADR, Caetano BC, Resende PC, Motta FC, Siqueira MM, Girard-Dias W, Archanjo BS, Barth OM. Morphology and morphogenesis of SARS-CoV-2 in Vero-E6 cells. Mem Inst Oswaldo Cruz 2021; 116:e200443. [PMID: 33566951 PMCID: PMC7874846 DOI: 10.1590/0074-02760200443] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 01/04/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The coronaviruses (CoVs) called the attention of the world for causing outbreaks of severe acute respiratory syndrome (SARS-CoV), in Asia in 2002-03, and respiratory disease in the Middle East (MERS-CoV), in 2012. In December 2019, yet again a new coronavirus (SARS-CoV-2) first identified in Wuhan, China, was associated with a severe respiratory infection, known today as COVID-19. This new virus quickly spread throughout China and 30 additional countries. As result, the World Health Organization (WHO) elevated the status of the COVID-19 outbreak from emergency of international concern to pandemic on March 11, 2020. The impact of COVID-19 on public health and economy fueled a worldwide race to approve therapeutic and prophylactic agents, but so far, there are no specific antiviral drugs or vaccines available. In current scenario, the development of in vitro systems for viral mass production and for testing antiviral and vaccine candidates proves to be an urgent matter. OBJECTIVE The objective of this paper is study the biology of SARS-CoV-2 in Vero-E6 cells at the ultrastructural level. METHODS In this study, we documented, by transmission electron microscopy and real-time reverse transcription polymerase chain reaction (RT-PCR), the infection of Vero-E6 cells with SARS-CoV-2 samples isolated from Brazilian patients. FINDINGS The infected cells presented cytopathic effects and SARS-CoV-2 particles were observed attached to the cell surface and inside cytoplasmic vesicles. The entry of the virus into cells occurred through the endocytic pathway or by fusion of the viral envelope with the cell membrane. Assembled nucleocapsids were verified inside rough endoplasmic reticulum cisterns (RER). Viral maturation seemed to occur by budding of viral particles from the RER into smooth membrane vesicles. MAIN CONCLUSIONS Therefore, the susceptibility of Vero-E6 cells to SARS-CoV-2 infection and the viral pathway inside the cells were demonstrated by ultrastructural analysis.
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Affiliation(s)
- Debora Ferreira Barreto-Vieira
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Morfologia e Morfogênese Viral, Rio de Janeiro, RJ, Brasil
| | - Marcos Alexandre Nunes da Silva
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Morfologia e Morfogênese Viral, Rio de Janeiro, RJ, Brasil
| | - Cristiana Couto Garcia
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Vírus Respiratórios e do Sarampo, Rio de Janeiro, RJ, Brasil
| | - Milene Dias Miranda
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Vírus Respiratórios e do Sarampo, Rio de Janeiro, RJ, Brasil
| | - Aline da Rocha Matos
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Vírus Respiratórios e do Sarampo, Rio de Janeiro, RJ, Brasil
| | - Braulia Costa Caetano
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Vírus Respiratórios e do Sarampo, Rio de Janeiro, RJ, Brasil
| | - Paola Cristina Resende
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Vírus Respiratórios e do Sarampo, Rio de Janeiro, RJ, Brasil
| | - Fernando Couto Motta
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Vírus Respiratórios e do Sarampo, Rio de Janeiro, RJ, Brasil
| | - Marilda Mendonça Siqueira
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Vírus Respiratórios e do Sarampo, Rio de Janeiro, RJ, Brasil
| | - Wendell Girard-Dias
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Plataforma de Microscopia Eletrônica Rudolph Barth, Rio de Janeiro, RJ, Brasil
| | - Bráulio Soares Archanjo
- Instituto Nacional de Metrologia, Qualidade e Tecnologia, Núcleo de Laboratórios de Microscopia, Rio de Janeiro, RJ, Brasil
| | - Ortrud Monika Barth
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Morfologia e Morfogênese Viral, Rio de Janeiro, RJ, Brasil
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Lopes-Torres EJ, Girard-Dias W, de Souza W, Miranda K. On the structural organization of the bacillary band of Trichuris muris under cryopreparation protocols and three-dimensional electron microscopy. J Struct Biol 2020; 212:107611. [PMID: 32890779 DOI: 10.1016/j.jsb.2020.107611] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 08/20/2020] [Accepted: 08/28/2020] [Indexed: 10/23/2022]
Abstract
Whipworms of the genus Trichuris are nematode parasites that infect mammals and can lead to various intestinal diseases of human and veterinary interest. The most intimate interaction between the parasite and the host intestine occurs through the anterior region of the nematode body, inserted into the intestinal mucosa during infection. One of the most prominent structures of the nematode surface found at the infection site is the bacillary band, a surface domain formed by a number of cells, mostly stichocytes and bacillary glands, whose structure and function are still under debate. Here, we used confocal microscopy, field emission scanning electron microscopy, helium ion microscopy, transmission electron microscopy and FIB-SEM tomography to unveil the functional role of the bacillary gland cell. We analyzed the surface organization as well as the intracellular milieu of the bacillary glands of Trichuris muris in high pressure frozen/freeze-substituted samples. Results showed that the secretory content is preserved in all gland openings, presenting a projected pattern. FIB-SEM analysis showed that the lamellar zone within the bacillary gland chamber is formed by a set of lacunar structures that may exhibit secretory or absorptive functions. In addition, incubation of parasites with the fluid phase endocytosis marker sulforhodamine B showed a time-dependent uptake by the parasite mouth, followed by perfusion through different tissues with ultimate secretion through the bacillary gland. Taken together, the results show that the bacillary gland possess structural characteristics of secretory and absorptive cells and unequivocally demonstrate that the bacillary gland cell functions as a secretory structure.
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Affiliation(s)
- E J Lopes-Torres
- Laboratório de Helmintologia Romero Lascasas Porto, Universidade do Estado do Rio de Janeiro, Departamento de Microbiologia, Imunologia e Parasitologia, Brazil.
| | - W Girard-Dias
- Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
| | - W de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho and Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho, s/n Centro de Ciências da Saúde, Bloco G, CEP: 21941-902, Rio de Janeiro, Brazil; Instituto Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Brazil
| | - K Miranda
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho and Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho, s/n Centro de Ciências da Saúde, Bloco G, CEP: 21941-902, Rio de Janeiro, Brazil; Instituto Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Brazil.
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Lopes-Torres E, Girard-Dias W, Mello W, Simões R, Pinto I, Maldonado A, De Souza W, Miranda K. Taxonomy of Physaloptera mirandai (Nematoda: Physalopteroidea) based in three-dimensional microscopy and phylogenetic positioning. Acta Trop 2019; 195:115-126. [PMID: 31039334 DOI: 10.1016/j.actatropica.2019.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 02/08/2019] [Accepted: 04/01/2019] [Indexed: 02/05/2023]
Abstract
Gastrointestinal nematodes are important ecological assets for the maintenance of the biodiversity in the Atlantic Forest in Brazil. They parasitize a number of animals of the local fauna, in which some species can promote serious injuries in the stomach wall of their hosts, which may lead to death. Among these nematodes, parasites of the genus Physaloptera are known to parasitize mammals (particularly carnivores and small rodents), birds and reptiles, being important for the local biodiversity. In this work, three hundred and sixty-two nematodes were recovered from the stomach of twenty-one Metachirus nudicaudatus (Didelphimorphia: Didelphidae) collected in Duas Bocas Biological Reserve, State of Espírito Santo, one of the largest Atlantic Forest remnants and important wildlife refuge of the Atlantic Forest in Brazil. Analysis using fluorescence and scanning electron microscopy as well as phylogenetic assessment using the mitochondrial cytochrome c oxidase subunit I gene showed that the parasites belong to the Physaloptera. Our results show details of the nematode morphology including the cloacal papillae distribution, cuticular topography details, 2D and 3D measurements of the structures with taxonomic importance. Molecular data confirmed the validity of P. mirandai and the phylogeny supported the monophyly of the assemblage formed by Physaloptera and Turgida. The use of a combination of quantitative and multidimensional microscopy tools, such as 3D reconstruction and modeling, allied to phylogenetic analysis may provide grounds for a new approach on helminth taxonomy and structural characterization.
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Schoijet AC, Miranda K, Sternlieb T, Barrera NM, Girard-Dias W, de Souza W, Alonso GD. TbVps15 is required for vesicular transport and cytokinesis in Trypanosoma brucei. Mol Biochem Parasitol 2017; 219:33-41. [PMID: 29155083 DOI: 10.1016/j.molbiopara.2017.11.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 11/10/2017] [Accepted: 11/11/2017] [Indexed: 01/20/2023]
Abstract
The class III phosphatidylinositol 3-kinase (PI3K) Vps34 is an important regulator of key cellular functions, including cell growth, survival, intracellular trafficking, autophagy and nutrient sensing. In yeast, Vps34 is associated with the putative serine/threonine protein kinase Vps15, however, its role in signaling has not been deeply evaluated. Here, we have identified the Vps15 orthologue in Trypanosoma brucei, named TbVps15. Knockdown of TbVps15 expression by interference RNA resulted in inhibition of cell growth and blockage of cytokinesis. Scanning electron microcopy revealed a variety of morphological abnormalities, with enlarged parasites and dividing cells that often exhibited a detached flagellum. Transmission electron microscopy analysis of TbVps15 RNAi cells showed an increase in intracellular vacuoles of the endomembrane system and some cells displayed an enlargement of the flagellar pocket, a common feature of cells defective in endocytosis. Moreover, uptake of dextran, transferrin and Concanavalin A was impaired. Finally, TbVps15 downregulation affected the PI3K activity, supporting the hypothesis that TbVps15 and TbVps34 form a complex as occurs in other organisms. In summary, we propose that TbVps15 has a role in the maintenance of cytokinesis, endocytosis and intracellular trafficking in T. brucei.
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Affiliation(s)
- Alejandra C Schoijet
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI-CONICET), Buenos Aires, Argentina; Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina
| | - Kildare Miranda
- Laboratorio de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho and Centro Nacional de Biologia Estrutural e Bioimagem (CENABIO), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Instituto Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Tamara Sternlieb
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI-CONICET), Buenos Aires, Argentina
| | - Nadia M Barrera
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI-CONICET), Buenos Aires, Argentina
| | - Wendell Girard-Dias
- Laboratorio de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho and Centro Nacional de Biologia Estrutural e Bioimagem (CENABIO), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Plataforma de Microscopia Eletrônica Rudolf Barth IOC, Fiocruz, Rio de Janeiro, Brazil
| | - Wanderley de Souza
- Laboratorio de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho and Centro Nacional de Biologia Estrutural e Bioimagem (CENABIO), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Instituto Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Guillermo D Alonso
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI-CONICET), Buenos Aires, Argentina; Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina.
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Ramos CL, Gomes FM, Girard-Dias W, Almeida FP, Albuquerque PC, Kretschmer M, Kronstad JW, Frases S, de Souza W, Rodrigues ML, Miranda K. Phosphorus-rich structures and capsular architecture in Cryptococcus neoformans. Future Microbiol 2017; 12:227-238. [PMID: 28262043 DOI: 10.2217/fmb-2017-0060] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM In this study, we aimed to analyze the relationship of phosphorus-rich structures with surface architecture in Cryptococcus neoformans. METHODS Phosphorus-rich structures in C. neoformans were analyzed by combining fluorescence microscopy, biochemical extraction, scanning electron microscopy, electron probe x-ray microanalysis and 3D reconstruction of high pressure frozen and freeze substituted cells by focused ion beam-scanning electron microscopy (FIB-SEM). RESULTS & CONCLUSION Intracellular and surface phosphorus-enriched structures were identified. These molecules were required for capsule assembly, as demonstrated in experiments using polysaccharide incorporation by capsule-deficient cells and mutants with defects in polyphosphate synthesis. The demonstration of intracellular and cell wall-associated polyphosphates in C. neoformans may lead to future studies involving their participation in both physiologic and pathogenic events.
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Affiliation(s)
- Caroline L Ramos
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fabio M Gomes
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Wendell Girard-Dias
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Instituto Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil
| | - Fernando P Almeida
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Instituto Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Priscila C Albuquerque
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Centro de Desenvolvimento Tecnológico em Saúde (CDTS), Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Matthias Kretschmer
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - James W Kronstad
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.,Department of Microbiology & Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Susana Frases
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Instituto Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Instituto Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcio L Rodrigues
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Centro de Desenvolvimento Tecnológico em Saúde (CDTS), Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Kildare Miranda
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Instituto Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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Guerreiro LH, Silva DD, Girard-Dias W, Mascarenhas CM, Miranda K, Sola-Penna M, Ricci Júnior E, Lima LMTDRE. Macromolecular confinement of therapeutic protein in polymeric particles for controlled release: insulin as a case study. BRAZ J PHARM SCI 2017. [DOI: 10.1590/s2175-97902017000216039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Luiz Henrique Guerreiro
- Federal University of Rio de Janeiro, Brazil; Rural Federal University of Rio de Janeiro, Brazil
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Augusto I, Monteiro D, Girard-Dias W, Dos Santos TO, Rosa Belmonte SL, Pinto de Oliveira J, Mauad H, da Silva Pacheco M, Lenz D, Stefanon Bittencourt A, Valentim Nogueira B, Lopes Dos Santos JR, Miranda K, Guimarães MCC. Virtual Reconstruction and Three-Dimensional Printing of Blood Cells as a Tool in Cell Biology Education. PLoS One 2016; 11:e0161184. [PMID: 27526196 PMCID: PMC4985121 DOI: 10.1371/journal.pone.0161184] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 08/01/2016] [Indexed: 12/22/2022] Open
Abstract
The cell biology discipline constitutes a highly dynamic field whose concepts take a long time to be incorporated into the educational system, especially in developing countries. Amongst the main obstacles to the introduction of new cell biology concepts to students is their general lack of identification with most teaching methods. The introduction of elaborated figures, movies and animations to textbooks has given a tremendous contribution to the learning process and the search for novel teaching methods has been a central goal in cell biology education. Some specialized tools, however, are usually only available in advanced research centers or in institutions that are traditionally involved with the development of novel teaching/learning processes, and are far from becoming reality in the majority of life sciences schools. When combined with the known declining interest in science among young people, a critical scenario may result. This is especially important in the field of electron microscopy and associated techniques, methods that have greatly contributed to the current knowledge on the structure and function of different cell biology models but are rarely made accessible to most students. In this work, we propose a strategy to increase the engagement of students into the world of cell and structural biology by combining 3D electron microscopy techniques and 3D prototyping technology (3D printing) to generate 3D physical models that accurately and realistically reproduce a close-to-the native structure of the cell and serve as a tool for students and teachers outside the main centers. We introduce three strategies for 3D imaging, modeling and prototyping of cells and propose the establishment of a virtual platform where different digital models can be deposited by EM groups and subsequently downloaded and printed in different schools, universities, research centers and museums, thereby modernizing teaching of cell biology and increasing the accessibility to modern approaches in basic science.
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Affiliation(s)
- Ingrid Augusto
- Laboratório de Ultraestrutura Celular Carlos Alberto Redins, Biotecnologia, Universidade Federal do Espírito Santo, Vitória, Brazil.,Instituto de Biofísica Carlos Chagas Filho e Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Douglas Monteiro
- Instituto de Biofísica Carlos Chagas Filho e Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Wendell Girard-Dias
- Instituto de Biofísica Carlos Chagas Filho e Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Thaisa Oliveira Dos Santos
- Laboratório de Ultraestrutura Celular Carlos Alberto Redins, Biotecnologia, Universidade Federal do Espírito Santo, Vitória, Brazil
| | | | - Jairo Pinto de Oliveira
- Laboratório de Ultraestrutura Celular Carlos Alberto Redins, Biotecnologia, Universidade Federal do Espírito Santo, Vitória, Brazil
| | - Helder Mauad
- Departamento de Fisiologia, Universidade Federal do Espírito Santo, Vitória, Brazil
| | | | - Dominik Lenz
- Ciências Farmacêuticas, Universidade de Vila Velha, Vila Velha, Brazil
| | | | - Breno Valentim Nogueira
- Laboratório de Ultraestrutura Celular Carlos Alberto Redins, Biotecnologia, Universidade Federal do Espírito Santo, Vitória, Brazil
| | | | - Kildare Miranda
- Instituto de Biofísica Carlos Chagas Filho e Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marco Cesar Cunegundes Guimarães
- Laboratório de Ultraestrutura Celular Carlos Alberto Redins, Biotecnologia, Universidade Federal do Espírito Santo, Vitória, Brazil
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Holandino C, Teixeira CAA, de Oliveira FAG, Barbosa GM, Siqueira CM, Messeder DJ, de Aguiar FS, da Veiga VF, Girard-Dias W, Miranda K, Galina A, Capella MAM, Morales MM. Direct electric current treatment modifies mitochondrial function and lipid body content in the A549 cancer cell line. Bioelectrochemistry 2016; 111:83-92. [PMID: 27243447 DOI: 10.1016/j.bioelechem.2016.05.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 05/09/2016] [Accepted: 05/09/2016] [Indexed: 02/04/2023]
Abstract
Electrochemical therapy (EChT) entails treatment of solid tumors with direct electric current (DC). This work evaluated the specific effects of anodic flow generated by DC on biochemical and metabolic features of the A549 human lung cancer cell line. Apoptosis was evaluated on the basis of caspase-3 activity and mitochondrial transmembrane potential dissipation. Cell morphology was analyzed using transmission electron microscopy, and lipid droplets were studied through morphometric analysis and X-ray qualitative elemental microanalysis. High-resolution respirometry was used to assess mitochondrial respiratory parameters. Results indicated A549 viability decreased in a dose-dependent manner with a prominent drop between 18 and 24h after treatment (p<0.001), together with a two-fold increase in caspase-3 activity. AF-treatment induced a significantly increase (p<0.01) in the cell number with disrupted mitochondrial transmembrane potential. Furthermore, treated cells demonstrated important ultrastructural mitochondria damage and a three-fold increase in the cytoplasmic lipid bodies' number, quantified by morphometrical analyses. Conversely, 24h after treatment, the cells presented a two-fold increase of residual oxygen consumption, accounting for 45.3% of basal oxygen consumption. These results show remarkable alterations promoted by anodic flow on human lung cancer cells which are possibly involved with the antitumoral effects of EChT.
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Affiliation(s)
- Carla Holandino
- Laboratory of Multidisciplinary Pharmaceutical Sciences, College of Pharmacy, Center of Health Sciences (CCS), Federal University do Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Cesar Augusto Antunes Teixeira
- Laboratory of Multidisciplinary Pharmaceutical Sciences, College of Pharmacy, Center of Health Sciences (CCS), Federal University do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Felipe Alves Gomes de Oliveira
- Laboratory of Multidisciplinary Pharmaceutical Sciences, College of Pharmacy, Center of Health Sciences (CCS), Federal University do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Gleyce Moreno Barbosa
- Laboratory of Multidisciplinary Pharmaceutical Sciences, College of Pharmacy, Center of Health Sciences (CCS), Federal University do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Camila Monteiro Siqueira
- Federal Institute of Education, Science and Technology of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Douglas Jardim Messeder
- Laboratory of Bioenergetics and Mitochondrial Physiology, Institute of Medical Biochemistry, CCS, Federal University do Rio de Janeiro, Brazil
| | - Fernanda Silva de Aguiar
- Laboratory of Multidisciplinary Pharmaceutical Sciences, College of Pharmacy, Center of Health Sciences (CCS), Federal University do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Venicio Feo da Veiga
- Laboratory of Electron Microscopy, Institute of Microbiology Prof. Paulo de Góes (IMPPG), CCS, UFRJ, Rio de Janeiro, Brazil
| | - Wendell Girard-Dias
- Laboratory of Cellular Ultrastructure Hertha Meyer, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Kildare Miranda
- Laboratory of Cellular Ultrastructure Hertha Meyer, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Antonio Galina
- Laboratory of Bioenergetics and Mitochondrial Physiology, Institute of Medical Biochemistry, CCS, Federal University do Rio de Janeiro, Brazil
| | | | - Marcelo Marcos Morales
- Laboratory of Molecular and Cellular Physiology, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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10
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Abstract
Extracellular vesicles (EV) are important carriers of biologically active components in a number of organisms, including fungal cells. Experimental characterization of fungal EVs suggested that these membranous compartments are likely involved in the regulation of several biological events. In fungal pathogens, these events include mechanisms of disease progression and/or control, suggesting potential targets for therapeutic intervention or disease prophylaxis. In this manuscript we describe methods that have been used in the last 10 years for the characterization of EVs produced by yeast forms of several fungal species. Experimental approaches detailed in this chapter include ultracentrifugation methods for EV fractionation, chromatographic approaches for analysis of EV lipids, microscopy techniques for analysis of both intracellular and extracellular vesicular compartments, interaction of EVs with host cells, and physical chemical analysis of EVs by dynamic light scattering.
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Affiliation(s)
- Marcio L Rodrigues
- Fundação Oswaldo Cruz (Fiocruz), Centro de Desenvolvimento Tecnológico em Saúde (CDTS) Fundação Oswaldo Cruz, Avenida Brasil, 4036, Sala 814, Rio de Janeiro, RJ, Brazil.
- Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
| | - Debora L Oliveira
- Fundação Oswaldo Cruz (Fiocruz), Centro de Desenvolvimento Tecnológico em Saúde (CDTS) Fundação Oswaldo Cruz, Avenida Brasil, 4036, Sala 814, Rio de Janeiro, RJ, Brazil
| | - Gabriele Vargas
- Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Wendell Girard-Dias
- Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ, Brazil
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho and Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Anderson J Franzen
- Laboratório de Tecnologia em Cultura de Células, Centro Universitário Estadual da Zona Oeste, Rio de Janeiro, RJ, Brazil
| | - Susana Frasés
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho and Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- Laboratório de Biologia Estrutural, Diretoria de Programas, Instituto Nacional de Metrologia, Normalização e Qualidade Industrial (INMETRO), Xerém, Rio de Janeiro, RJ, Brazil
| | - Kildare Miranda
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho and Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Leonardo Nimrichter
- Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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11
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Niyogi S, Jimenez V, Girard-Dias W, de Souza W, Miranda K, Docampo R. Rab32 is essential for maintaining functional acidocalcisomes, and for growth and infectivity of Trypanosoma cruzi. J Cell Sci 2015; 128:2363-73. [PMID: 25964650 DOI: 10.1242/jcs.169466] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 04/30/2015] [Indexed: 02/01/2023] Open
Abstract
The contractile vacuole complex (CVC) of Trypanosoma cruzi, the etiologic agent of Chagas disease, collects and expels excess water as a mechanism of regulatory volume decrease after hyposmotic stress; it also has a role in cell shrinking after hyperosmotic stress. Here, we report that, in addition to its role in osmoregulation, the CVC of T. cruzi has a role in the biogenesis of acidocalcisomes. Expression of dominant-negative mutants of the CVC-located small GTPase Rab32 (TcCLB.506289.80) results in lower numbers of less-electron-dense acidocalcisomes, lower content of polyphosphate, lower capacity for acidocalcisome acidification and Ca(2+) uptake that is driven by the vacuolar proton pyrophosphatase and the Ca(2+)-ATPase, respectively, as well as less-infective parasites, revealing the role of this organelle in parasite infectivity. By using fluorescence, electron microscopy and electron tomography analyses, we provide further evidence of the active contact of acidocalcisomes with the CVC, indicating an active exchange of proteins between the two organelles.
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Affiliation(s)
- Sayantanee Niyogi
- Department of Cellular Biology and Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
| | - Veronica Jimenez
- Department of Cellular Biology and Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
| | - Wendell Girard-Dias
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho and Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens - Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho and Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens - Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil Diretoria de Metrologia Aplicada a Ciências da Vida, Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Xerém, Rio de Janeiro 25250-020, Brazil
| | - Kildare Miranda
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho and Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens - Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil Diretoria de Metrologia Aplicada a Ciências da Vida, Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Xerém, Rio de Janeiro 25250-020, Brazil
| | - Roberto Docampo
- Department of Cellular Biology and Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
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Miranda K, Girard-Dias W, Attias M, de Souza W, Ramos I. Three dimensional reconstruction by electron microscopy in the life sciences: An introduction for cell and tissue biologists. Mol Reprod Dev 2015; 82:530-47. [PMID: 25652003 DOI: 10.1002/mrd.22455] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 12/10/2014] [Indexed: 12/26/2022]
Abstract
Early applications of transmission electron microscopy (TEM) in the life sciences have contributed tremendously to our current understanding at the subcellular level. Initially limited to two-dimensional representations of three-dimensional (3D) objects, this approach has revolutionized the fields of cellular and structural biology-being instrumental for determining the fine morpho-functional characterization of most cellular structures. Electron microscopy has progressively evolved towards the development of tools that allow for the 3D characterization of different structures. This was done with the aid of a wide variety of techniques, which have become increasingly diverse and highly sophisticated. We start this review by examining the principles of 3D reconstruction of cells and tissues using classical approaches in TEM, and follow with a discussion of the modern approaches utilizing TEM as well as on new scanning electron microscopy-based techniques. 3D reconstruction techniques from serial sections and (cryo) electron-tomography are examined, and the recent applications of focused ion beam-scanning microscopes and serial-block-face techniques for the 3D reconstruction of large volumes are discussed. Alternative low-cost techniques and more accessible approaches using basic transmission or field emission scanning electron microscopes are also examined.
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Affiliation(s)
- Kildare Miranda
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica, Carlos Chagas Filho and Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens-Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Diretoria de Metrologia Aplicada a Ciências da Vida, Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Xer, é, m, Rio de Janeiro, Brazil
| | - Wendell Girard-Dias
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica, Carlos Chagas Filho and Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens-Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcia Attias
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica, Carlos Chagas Filho and Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens-Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica, Carlos Chagas Filho and Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens-Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Diretoria de Metrologia Aplicada a Ciências da Vida, Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Xer, é, m, Rio de Janeiro, Brazil
| | - Isabela Ramos
- Laboratório de Bioquímica de Insetos, Instituto de Bioquímica Médica, Leopoldo de Meis -Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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13
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Gomes FM, Ramos IB, Wendt C, Girard-Dias W, De Souza W, Machado EA, Miranda K. New insights into the in situ microscopic visualization and quantification of inorganic polyphosphate stores by 4',6-diamidino-2-phenylindole (DAPI)-staining. Eur J Histochem 2013; 57:e34. [PMID: 24441187 PMCID: PMC3896036 DOI: 10.4081/ejh.2013.e34] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 09/22/2013] [Accepted: 09/24/2013] [Indexed: 01/10/2023] Open
Abstract
Inorganic polyphosphate (PolyP) is a biological polymer that plays important roles in the cell physiology of both prokaryotic and eukaryotic organisms. Among the available methods for PolyP localization and quantification, a 4',6-diamidino-2-phenylindole(DAPI)-based assay has been used for visualization of PolyP-rich organelles. Due to differences in DAPI permeability to different compartments and/or PolyP retention after fixation, a general protocol for DAPI-PolyP staining has not yet been established. Here, we tested different protocols for DAPI-PolyP detection in a range of samples with different levels of DAPI permeability, including subcellular fractions, free-living cells and cryosections of fixed tissues. Subcellular fractions of PolyP-rich organelles yielded DAPI-PolyP fluorescence, although those with a complex external layer usually required longer incubation times, previous aldehyde fixation and/or detergent permeabilization. DAPI-PolyP was also detected in cryosections of OCT-embedded tissues analyzed by multi-photon microscopy. In addition, a semi-quantitative fluorimetric analysis of DAPI-stained fractions showed PolyP mobilization in a similar fashion to what has been demonstrated with the use of enzyme-based quantitative protocols. Taken together, our results support the use of DAPI for both PolyP visualization and quantification, although specific steps are suggested as a general guideline for DAPI-PolyP staining in biological samples with different degrees of DAPI and PolyP permeability.
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Affiliation(s)
- F M Gomes
- Universidade Federal do Rio de Janeiro.
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14
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Girard-Dias W, Alcântara CL, Cunha-e-Silva N, de Souza W, Miranda K. On the ultrastructural organization of Trypanosoma cruzi using cryopreparation methods and electron tomography. Histochem Cell Biol 2012; 138:821-31. [PMID: 22872316 DOI: 10.1007/s00418-012-1002-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/09/2012] [Indexed: 02/02/2023]
Abstract
The structural organization of Trypanosoma cruzi has been intensely investigated by different microscopy techniques. At the electron microscopy level, bi-dimensional analysis of thin sections of chemically fixed cells has been one of the most commonly used techniques, despite the known potential of generating artifacts during chemical fixation and the subsequent steps of sample preparation. In contrast, more sophisticated and elaborate techniques, such as cryofixation followed by freeze substitution that are known to preserve the samples in a more close-to-native state, have not been widely applied to T. cruzi. In addition, the 3D characterization of such cells has been carried out mostly using 3D reconstruction from serial sections, currently considered a low resolution technique when compared to electron tomography (ET). In this work, we re-visited the 3D ultrastructure of T. cruzi using a combination of two approaches: (1) analysis of both conventionally processed and cryofixed and freeze substituted cells and (2) 3D reconstruction of large volumes by serial electron tomography. The analysis of high-pressure frozen and freeze substituted parasites showed novel characteristics in a number of intracellular structures, both in their structure and content. Organelles generally showed a smooth and regular morphology in some cases presenting a characteristic electron dense content. Ribosomes and new microtubule sets showed an unexpected localization in the cell body. The improved preservation and imaging in 3D of T. cruzi cells using cryopreparation techniques has revealed some novel aspects of the ultrastructural organization of this parasite.
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Affiliation(s)
- Wendell Girard-Dias
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho and Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho, 373. Bloco G-subsolo, Cidade Universitária, Rio de Janeiro 21941-902, Brazil
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de Jesus TCL, Tonelli RR, Nardelli SC, da Silva Augusto L, Motta MCM, Girard-Dias W, Miranda K, Ulrich P, Jimenez V, Barquilla A, Navarro M, Docampo R, Schenkman S. Target of rapamycin (TOR)-like 1 kinase is involved in the control of polyphosphate levels and acidocalcisome maintenance in Trypanosoma brucei. J Biol Chem 2010; 285:24131-40. [PMID: 20495004 DOI: 10.1074/jbc.m110.120212] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Target of rapamycin (TOR) kinases are highly conserved protein kinases that integrate signals from nutrients and growth factors to coordinate cell growth and cell cycle progression. It has been previously described that two TOR kinases control cell growth in the protozoan parasite Trypanosoma brucei, the causative agent of African trypanosomiasis. Here we studied an unusual TOR-like protein named TbTOR-like 1 containing a PDZ domain and found exclusively in kinetoplastids. TbTOR-like 1 localizes to unique cytosolic granules. After hyperosmotic stress, the localization of the protein shifts to the cell periphery, different from other organelle markers. Ablation of TbTOR-like 1 causes a progressive inhibition of cell proliferation, producing parasites accumulating in the S/G(2) phase of the cell cycle. TbTOR-like 1 knocked down cells have an increased area occupied by acidic vacuoles, known as acidocalcisomes, and are enriched in polyphosphate and pyrophosphate. These results suggest that TbTOR-like 1 might be involved in the control of acidocalcisome and polyphosphate metabolism in T. brucei.
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Schoijet AC, Miranda K, Girard-Dias W, de Souza W, Flawiá MM, Torres HN, Docampo R, Alonso GD. A Trypanosoma cruzi phosphatidylinositol 3-kinase (TcVps34) is involved in osmoregulation and receptor-mediated endocytosis. J Biol Chem 2008; 283:31541-50. [PMID: 18801733 DOI: 10.1074/jbc.m801367200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Trypanosoma cruzi, the etiological agent of Chagas disease, has the ability to respond to a variety of environmental changes during its life cycle both in the insect vector and in the vertebrate host. Because regulation of transcription initiation seems to be nonfunctional in this parasite, it is important to investigate other regulatory mechanisms of adaptation. Regulatory mechanisms at the level of signal transduction pathways involving phosphoinositides are good candidates for this purpose. Here we report the identification of the first phosphatidylinositol 3-kinase (PI3K) in T. cruzi, with similarity with its yeast counterpart, Vps34p. TcVps34 specifically phosphorylates phosphatidylinositol to produce phosphatidylinositol 3-phosphate, thus confirming that it belongs to class III PI3K family. Overexpression of TcVps34 resulted in morphological and functional alterations related to vesicular trafficking. Although inhibition of TcVps34 with specific PI3K inhibitors, such as wortmannin and LY294,000, resulted in reduced regulatory volume decrease after hyposmotic stress, cells overexpressing this enzyme were resistant to these inhibitors. Furthermore, these cells were able to recover their original volume faster than wild type cells when they were submitted to severe hyposmotic stress. In addition, in TcVps34-overexpressing cells, the activities of vacuolar-H+-ATPase and vacuolar H+-pyrophosphatase were altered, suggesting defects in the acidification of intracellular compartments. Furthermore, receptor-mediated endocytosis was partially blocked although fluid phase endocytosis was not affected, confirming a function for TcVps34 in membrane trafficking. Taken together, these results strongly support that TcVps34 plays a prominent role in vital processes for T. cruzi survival such as osmoregulation, acidification, and vesicular trafficking.
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Affiliation(s)
- Alejandra C Schoijet
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas yTécnicas, Universidad de Buenos Aires, Vuelta de Obligado 2490 (1428), Buenos Aires, Argentina
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