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Dacos M, Immordino B, Diroff E, Sicard G, Kosta A, Rodallec A, Giacometti S, Ciccolini J, Fanciullino R. Pegylated liposome encapsulating docetaxel using microfluidic mixing technique: Process optimization and results in breast cancer models. Int J Pharm 2024; 656:124091. [PMID: 38588758 DOI: 10.1016/j.ijpharm.2024.124091] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 04/04/2024] [Accepted: 04/04/2024] [Indexed: 04/10/2024]
Abstract
The development of nanoparticles could help to improve the efficacy/toxicity balance of drugs. This project aimed to develop liposomes and immunoliposomes using microfluidic mixing technology.Various formulation tests were carried out to obtain liposomes that met the established specifications. The liposomes were then characterized in terms of size, polydispersity index (PDI), docetaxel encapsulation rate and lamellarity. Antiproliferative activity was tested in human breast cancer models ranging from near-negative (MDA-MB-231), positive (MDA-MB-453) to HER2 positive. Pharmacokinetic studies were performed in C57BL/6 mice.Numerous batches of liposomes were synthesised using identical molar ratios and by varying the microfluidic parameters TFR, FRR and buffer. All synthesized liposomes have a size < 200 nm, but only Lipo-1, Lipo-6, Lipo-7, Lipo-8 have a PDI < 0.2, which meets our initial requirements. The size of the liposomes was correlated with the total FRR, for a 1:1 FRR the size is 122.2 ± 12.3 nm, whereas for a 1:3 FRR the size obtained is 163.4 ± 34.0 nm (p = 0.019. Three batches of liposomes were obtained with high docetaxel encapsulation rates > 80 %. Furthermore, in vitro studies on breast cancer cell lines demonstrated the efficacy of liposomes obtained by microfluidic mixing technique. These liposomes also showed improved pharmacokinetics compared to free docetaxel, with a longer half-life and higher AUC (3-fold and 3.5-fold increase for the immunoliposome, respectively).This suggests that switching to the microfluidic process will produce batches of liposomes with the same characteristics in terms of in vitro properties and efficacy, as well as the ability to release the encapsulated drug over time in vivo. This time-efficiency of the microfluidic technique is critical, especially in the early stages of development.
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Affiliation(s)
- Mathilde Dacos
- COMPO, SMARTc. CRCM: UMR Inserm 1068, CNRS UMR 7258, AMU U105, IPC, Marseille, France; Assitance Publique des Hôpitaux de Marseille, Marseille, France.
| | - Benoît Immordino
- Fondazione Pisana per La Scienza, 56017 San Giuliano, Pisa, Italy
| | - Erwan Diroff
- COMPO, SMARTc. CRCM: UMR Inserm 1068, CNRS UMR 7258, AMU U105, IPC, Marseille, France
| | - Guillaume Sicard
- COMPO, SMARTc. CRCM: UMR Inserm 1068, CNRS UMR 7258, AMU U105, IPC, Marseille, France; Assitance Publique des Hôpitaux de Marseille, Marseille, France
| | - Artemis Kosta
- Microscopy Core Facility, Institut de Microbiologie de la Méditerranée (FR3479), CNRS, Aix-Marseille Université, Marseille, France
| | - Anne Rodallec
- COMPO, SMARTc. CRCM: UMR Inserm 1068, CNRS UMR 7258, AMU U105, IPC, Marseille, France
| | - Sarah Giacometti
- COMPO, SMARTc. CRCM: UMR Inserm 1068, CNRS UMR 7258, AMU U105, IPC, Marseille, France
| | - Joseph Ciccolini
- COMPO, SMARTc. CRCM: UMR Inserm 1068, CNRS UMR 7258, AMU U105, IPC, Marseille, France; Assitance Publique des Hôpitaux de Marseille, Marseille, France
| | - Raphaëlle Fanciullino
- COMPO, SMARTc. CRCM: UMR Inserm 1068, CNRS UMR 7258, AMU U105, IPC, Marseille, France; Assitance Publique des Hôpitaux de Marseille, Marseille, France
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2
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Dessartine MM, Kosta A, Doan T, Cascales É, Côté JP. Type 1 fimbriae-mediated collective protection against type 6 secretion system attacks. mBio 2024; 15:e0255323. [PMID: 38497656 PMCID: PMC11005336 DOI: 10.1128/mbio.02553-23] [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: 09/27/2023] [Accepted: 01/25/2024] [Indexed: 03/19/2024] Open
Abstract
Bacterial competition may rely on secretion systems such as the type 6 secretion system (T6SS), which punctures and releases toxic molecules into neighboring cells. To subsist, bacterial targets must counteract the threats posed by T6SS-positive competitors. In this study, we used a comprehensive genome-wide high-throughput screening approach to investigate the dynamics of interbacterial competition. Our primary goal was to identify deletion mutants within the well-characterized E. coli K-12 single-gene deletion library, the Keio collection, that demonstrated resistance to T6SS-mediated killing by the enteropathogenic bacterium Cronobacter malonaticus. We identified 49 potential mutants conferring resistance to T6SS and focused our interest on a deletion mutant (∆fimE) exhibiting enhanced expression of type 1 fimbriae. We demonstrated that the presence of type 1 fimbriae leads to the formation of microcolonies and thus protects against T6SS-mediated assaults. Collectively, our study demonstrated that adhesive structures such as type 1 fimbriae confer collective protective behavior against T6SS attacks.IMPORTANCEType 6 secretion systems (T6SS) are molecular weapons employed by gram-negative bacteria to eliminate neighboring microbes. T6SS plays a pivotal role as a virulence factor, enabling pathogenic gram-negative bacteria to compete with the established communities to colonize hosts and induce infections. Gaining a deeper understanding of bacterial interactions will allow the development of strategies to control the action of systems such as the T6SS that can manipulate bacterial communities. In this context, we demonstrate that bacteria targeted by T6SS attacks from the enteric pathogen Cronobacter malonaticus, which poses a significant threat to infants, can develop a collective protective mechanism centered on the production of type I fimbriae. These adhesive structures promote the aggregation of bacterial preys and the formation of microcolonies, which protect the cells from T6SS attacks.
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Affiliation(s)
- Margot Marie Dessartine
- Département de biologie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Artemis Kosta
- Plateforme de microscopie, Institut de Microbiologie de la Méditerranée (IMM, FR3479), Aix-Marseille Univ, CNRS, Marseille, France
| | - Thierry Doan
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM, UMR7255), Institut de Microbiologie de la Méditerranée, Aix Marseille Univ, CNRS, Marseille, France
| | - Éric Cascales
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM, UMR7255), Institut de Microbiologie de la Méditerranée, Aix Marseille Univ, CNRS, Marseille, France
| | - Jean-Philippe Côté
- Département de biologie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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3
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Bongiovanni TR, Latario CJ, Le Cras Y, Trus E, Robitaille S, Swartz K, Schmidtke D, Vincent M, Kosta A, Orth J, Stengel F, Pellarin R, Rocha EPC, Ross BD, Durand E. Assembly of a unique membrane complex in type VI secretion systems of Bacteroidota. Nat Commun 2024; 15:429. [PMID: 38200008 PMCID: PMC10781749 DOI: 10.1038/s41467-023-44426-1] [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: 06/08/2023] [Accepted: 12/13/2023] [Indexed: 01/12/2024] Open
Abstract
The type VI secretion system (T6SS) of Gram-negative bacteria inhibits competitor cells through contact-dependent translocation of toxic effector proteins. In Proteobacteria, the T6SS is anchored to the cell envelope through a megadalton-sized membrane complex (MC). However, the genomes of Bacteroidota with T6SSs appear to lack genes encoding homologs of canonical MC components. Here, we identify five genes in Bacteroides fragilis (tssNQOPR) that are essential for T6SS function and encode a Bacteroidota-specific MC. We purify this complex, reveal its dimensions using electron microscopy, and identify a protein-protein interaction network underlying the assembly of the MC including the stoichiometry of the five TssNQOPR components. Protein TssN mediates the connection between the Bacteroidota MC and the conserved baseplate. Although MC gene content and organization varies across the phylum Bacteroidota, no MC homologs are detected outside of T6SS loci, suggesting ancient co-option and functional convergence with the non-homologous MC of Pseudomonadota.
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Affiliation(s)
- Thibault R Bongiovanni
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM), Institut de Microbiologie, Bioénergies et Biotechnologie (IM2B), Aix-Marseille Université - Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 7255, Institut national de la santé et de la recherche médicale (INSERM), Marseille, France
- Laboratoire de Chimie Bactérienne (LCB), Institut de Microbiologie, Bioénergies et Biotechnologie (IM2B), Aix-Marseille Université - Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 7255, Institut national de la santé et de la recherche médicale (INSERM), Marseille, France
| | - Casey J Latario
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH, 03755, USA
| | - Youn Le Cras
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris, France
| | - Evan Trus
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH, 03755, USA
| | - Sophie Robitaille
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH, 03755, USA
| | - Kerry Swartz
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH, 03755, USA
| | - Danica Schmidtke
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH, 03755, USA
- Department of Microbiology, University of Washington, Seattle, WA, 98109, USA
| | - Maxence Vincent
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM), Institut de Microbiologie, Bioénergies et Biotechnologie (IM2B), Aix-Marseille Université - Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 7255, Institut national de la santé et de la recherche médicale (INSERM), Marseille, France
- Laboratoire de Chimie Bactérienne (LCB), Institut de Microbiologie, Bioénergies et Biotechnologie (IM2B), Aix-Marseille Université - Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 7255, Institut national de la santé et de la recherche médicale (INSERM), Marseille, France
| | - Artemis Kosta
- Microscopy Core Facility, Institut de Microbiologie de la Méditerranée (IMM), FR3479, CNRS, Aix-Marseille University, Marseille, France
| | - Jan Orth
- Department of Biology, University of Konstanz, Universitätsstraße 10, 78457, Konstanz, Germany
- Konstanz Research School Chemical Biology, University of Konstanz, Universitätsstraße 10, 78457, Konstanz, Germany
| | - Florian Stengel
- Department of Biology, University of Konstanz, Universitätsstraße 10, 78457, Konstanz, Germany
- Konstanz Research School Chemical Biology, University of Konstanz, Universitätsstraße 10, 78457, Konstanz, Germany
| | - Riccardo Pellarin
- Molecular Microbiology and Structural Biochemistry (MMSB, UMR 5086), CNRS & University of Lyon, 7 Passage du Vercors, 69007, Lyon, France
| | - Eduardo P C Rocha
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris, France
| | - Benjamin D Ross
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH, 03755, USA.
- Department of Microbiology, University of Washington, Seattle, WA, 98109, USA.
| | - Eric Durand
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM), Institut de Microbiologie, Bioénergies et Biotechnologie (IM2B), Aix-Marseille Université - Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 7255, Institut national de la santé et de la recherche médicale (INSERM), Marseille, France.
- Laboratoire de Chimie Bactérienne (LCB), Institut de Microbiologie, Bioénergies et Biotechnologie (IM2B), Aix-Marseille Université - Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 7255, Institut national de la santé et de la recherche médicale (INSERM), Marseille, France.
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4
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Anger R, Pieulle L, Shahin M, Valette O, Le Guenno H, Kosta A, Pelicic V, Fronzes R. Structure of a heteropolymeric type 4 pilus from a monoderm bacterium. Nat Commun 2023; 14:7143. [PMID: 37932265 PMCID: PMC10628169 DOI: 10.1038/s41467-023-42872-5] [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: 06/15/2023] [Accepted: 10/24/2023] [Indexed: 11/08/2023] Open
Abstract
Type 4 pili (T4P) are important virulence factors, which belong to a superfamily of nanomachines ubiquitous in prokaryotes, called type 4 filaments (T4F). T4F are defined as helical polymers of type 4 pilins. Recent advances in cryo-electron microscopy (cryo-EM) led to structures of several T4F, revealing that the long N-terminal α-helix (α1) - the trademark of pilins - packs in the centre of the filaments to form a hydrophobic core. In diderm bacteria - all available bacterial T4F structures are from diderm species - a portion of α1 is melted (unfolded). Here we report that this architecture is conserved in phylogenetically distant monoderm species by determining the structure of Streptococcus sanguinis T4P. Our 3.7 Å resolution cryo-EM structure of S. sanguinis heteropolymeric T4P and the resulting full atomic model including all minor pilins highlight universal features of bacterial T4F and have widespread implications in understanding T4F biology.
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Affiliation(s)
- Robin Anger
- Institut Européen de Chimie et Biologie, Université de Bordeaux-CNRS (UMR 5234), Pessac, France
| | - Laetitia Pieulle
- Laboratoire de Chimie Bactérienne, Institut de Microbiologie de la Méditerranée, Aix-Marseille Université-CNRS (UMR 7283), Marseille, France
| | - Meriam Shahin
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Odile Valette
- Laboratoire de Chimie Bactérienne, Institut de Microbiologie de la Méditerranée, Aix-Marseille Université-CNRS (UMR 7283), Marseille, France
| | - Hugo Le Guenno
- Plateforme de Microscopie, Institut de Microbiologie de la Méditerranée, Aix-Marseille Université-CNRS, Marseille, France
| | - Artemis Kosta
- Plateforme de Microscopie, Institut de Microbiologie de la Méditerranée, Aix-Marseille Université-CNRS, Marseille, France
| | - Vladimir Pelicic
- Laboratoire de Chimie Bactérienne, Institut de Microbiologie de la Méditerranée, Aix-Marseille Université-CNRS (UMR 7283), Marseille, France.
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK.
| | - Rémi Fronzes
- Institut Européen de Chimie et Biologie, Université de Bordeaux-CNRS (UMR 5234), Pessac, France.
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5
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Kandolo O, Cherrak Y, Filella-Merce I, Le Guenno H, Kosta A, Espinosa L, Santucci P, Verthuy C, Lebrun R, Nilges M, Pellarin R, Durand E. Acinetobacter type VI secretion system comprises a non-canonical membrane complex. PLoS Pathog 2023; 19:e1011687. [PMID: 37769028 PMCID: PMC10564176 DOI: 10.1371/journal.ppat.1011687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 10/10/2023] [Accepted: 09/14/2023] [Indexed: 09/30/2023] Open
Abstract
A. baumannii can rapidly acquire new resistance mechanisms and persist on abiotic surface, enabling the colonization of asymptomatic human host. In Acinetobacter the type VI secretion system (T6SS) is involved in twitching, surface motility and is used for interbacterial competition allowing the bacteria to uptake DNA. A. baumannii possesses a T6SS that has been well studied for its regulation and specific activity, but little is known concerning its assembly and architecture. The T6SS nanomachine is built from three architectural sub-complexes. Unlike the baseplate (BP) and the tail-tube complex (TTC), which are inherited from bacteriophages, the membrane complex (MC) originates from bacteria. The MC is the most external part of the T6SS and, as such, is subjected to evolution and adaptation. One unanswered question on the MC is how such a gigantesque molecular edifice is inserted and crosses the bacterial cell envelope. The A. baumannii MC lacks an essential component, the TssJ lipoprotein, which anchors the MC to the outer membrane. In this work, we studied how A. baumannii compensates the absence of a TssJ. We have characterized for the first time the A. baumannii's specific T6SS MC, its unique characteristic, its membrane localization, and assembly dynamics. We also defined its composition, demonstrating that its biogenesis employs three Acinetobacter-specific envelope-associated proteins that define an intricate network leading to the assembly of a five-proteins membrane super-complex. Our data suggest that A. baumannii has divided the function of TssJ by (1) co-opting a new protein TsmK that stabilizes the MC and by (2) evolving a new domain in TssM for homo-oligomerization, a prerequisite to build the T6SS channel. We believe that the atypical species-specific features we report in this study will have profound implication in our understanding of the assembly and evolutionary diversity of different T6SSs, that warrants future investigation.
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Affiliation(s)
- Ona Kandolo
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires (LISM), Institut de Microbiologie, Bioénergies and Biotechnologie (IM2B), Aix-Marseille Université, Centre National de la Recherche Scientifique (CNRS)-UMR 7255, Marseille, France
| | - Yassine Cherrak
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires (LISM), Institut de Microbiologie, Bioénergies and Biotechnologie (IM2B), Aix-Marseille Université, Centre National de la Recherche Scientifique (CNRS)-UMR 7255, Marseille, France
| | - Isaac Filella-Merce
- Institut Pasteur, Structural Bioinformatics Unit, Department of Structural Biology and Chemistry, Paris, France
- Sorbonne Université, Collège doctoral, Paris, France
| | - Hugo Le Guenno
- Microscopy Core Facility, Aix Marseille Univ, CNRS, Institut de Microbiologie de la Méditerranée, Marseille Cedex 20, France
| | - Artemis Kosta
- Microscopy Core Facility, Aix Marseille Univ, CNRS, Institut de Microbiologie de la Méditerranée, Marseille Cedex 20, France
| | - Leon Espinosa
- Laboratoire de Chimie Bactérienne (LCB), Institut de Microbiologie, Bioénergies and Biotechnologie (IM2B), Aix-Marseille Université, Centre National de la Recherche Scientifique, Marseille, France
| | - Pierre Santucci
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires (LISM), Institut de Microbiologie, Bioénergies and Biotechnologie (IM2B), Aix-Marseille Université, Centre National de la Recherche Scientifique (CNRS)-UMR 7255, Marseille, France
| | - Christophe Verthuy
- Proteomic Core Facility IMM, Marseille Protéomique (MaP), Aix Marseille Univ, Marseille Cedex 20, France
| | - Régine Lebrun
- Proteomic Core Facility IMM, Marseille Protéomique (MaP), Aix Marseille Univ, Marseille Cedex 20, France
| | - Michael Nilges
- Institut Pasteur, Structural Bioinformatics Unit, Department of Structural Biology and Chemistry, Paris, France
| | - Riccardo Pellarin
- Institut Pasteur, Structural Bioinformatics Unit, Department of Structural Biology and Chemistry, Paris, France
| | - Eric Durand
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires (LISM), Institut de Microbiologie, Bioénergies and Biotechnologie (IM2B), Aix-Marseille Université, Centre National de la Recherche Scientifique (CNRS)-UMR 7255, Marseille, France
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires (LISM), Institut de Microbiologie, Bioénergies and Biotechnologie (IM2B), Aix-Marseille Université, Institut National de la Santé et de la Recherche Médicale (INSERM), Marseille, France
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6
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Chevrier DM, Juhin A, Menguy N, Bolzoni R, Soto-Rodriguez PED, Kojadinovic-Sirinelli M, Paterson GA, Belkhou R, Williams W, Skouri-Panet F, Kosta A, Le Guenno H, Pereiro E, Faivre D, Benzerara K, Monteil CL, Lefevre CT. Collective magnetotaxis of microbial holobionts is optimized by the three-dimensional organization and magnetic properties of ectosymbionts. Proc Natl Acad Sci U S A 2023; 120:e2216975120. [PMID: 36848579 PMCID: PMC10013862 DOI: 10.1073/pnas.2216975120] [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: 10/04/2022] [Accepted: 01/17/2023] [Indexed: 03/01/2023] Open
Abstract
Over the last few decades, symbiosis and the concept of holobiont-a host entity with a population of symbionts-have gained a central role in our understanding of life functioning and diversification. Regardless of the type of partner interactions, understanding how the biophysical properties of each individual symbiont and their assembly may generate collective behaviors at the holobiont scale remains a fundamental challenge. This is particularly intriguing in the case of the newly discovered magnetotactic holobionts (MHB) whose motility relies on a collective magnetotaxis (i.e., a magnetic field-assisted motility guided by a chemoaerotaxis system). This complex behavior raises many questions regarding how magnetic properties of symbionts determine holobiont magnetism and motility. Here, a suite of light-, electron- and X-ray-based microscopy techniques [including X-ray magnetic circular dichroism (XMCD)] reveals that symbionts optimize the motility, the ultrastructure, and the magnetic properties of MHBs from the microscale to the nanoscale. In the case of these magnetic symbionts, the magnetic moment transferred to the host cell is in excess (102 to 103 times stronger than free-living magnetotactic bacteria), well above the threshold for the host cell to gain a magnetotactic advantage. The surface organization of symbionts is explicitly presented herein, depicting bacterial membrane structures that ensure longitudinal alignment of cells. Magnetic dipole and nanocrystalline orientations of magnetosomes were also shown to be consistently oriented in the longitudinal direction, maximizing the magnetic moment of each symbiont. With an excessive magnetic moment given to the host cell, the benefit provided by magnetosome biomineralization beyond magnetotaxis can be questioned.
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Affiliation(s)
- Daniel M. Chevrier
- Aix-Marseille Université, Centre national de la recherche scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), UMR7265, Bioscience and biotechnology institute of Aix-Marseille (BIAM), Saint-Paul-lez-Durance13108, France
| | - Amélie Juhin
- Sorbonne Université, UMR CNRS 7590, Muséum national d'Histoire naturelle (MNHN), Institut de recherche pour le développement (IRD), Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), 75005Paris, France
| | - Nicolas Menguy
- Sorbonne Université, UMR CNRS 7590, Muséum national d'Histoire naturelle (MNHN), Institut de recherche pour le développement (IRD), Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), 75005Paris, France
| | - Romain Bolzoni
- Aix-Marseille Université, Centre national de la recherche scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), UMR7265, Bioscience and biotechnology institute of Aix-Marseille (BIAM), Saint-Paul-lez-Durance13108, France
| | - Paul E. D. Soto-Rodriguez
- Aix-Marseille Université, Centre national de la recherche scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), UMR7265, Bioscience and biotechnology institute of Aix-Marseille (BIAM), Saint-Paul-lez-Durance13108, France
| | - Mila Kojadinovic-Sirinelli
- Aix-Marseille Université, Centre national de la recherche scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), UMR7265, Bioscience and biotechnology institute of Aix-Marseille (BIAM), Saint-Paul-lez-Durance13108, France
| | - Greig A. Paterson
- Department of Earth, Ocean and Ecological Sciences, University of Liverpool, L69 7ZELiverpool, UK
| | - Rachid Belkhou
- Synchrotron Soleil, L'Orme des Merisiers, 91192Gif-sur-Yvette Cedex, France
| | - Wyn Williams
- School of GeoSciences, Grant Institute, University of Edinburgh, EdinburghEH9 3JW, UK
| | - Fériel Skouri-Panet
- Sorbonne Université, UMR CNRS 7590, Muséum national d'Histoire naturelle (MNHN), Institut de recherche pour le développement (IRD), Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), 75005Paris, France
| | - Artemis Kosta
- Plateforme de Microscopie de l'Institut de Microbiologie de la Méditerranée, Institut de Microbiologie, FR3479, Campus CNRS, 13402Marseille cedex 20, France
| | - Hugo Le Guenno
- Plateforme de Microscopie de l'Institut de Microbiologie de la Méditerranée, Institut de Microbiologie, FR3479, Campus CNRS, 13402Marseille cedex 20, France
| | - Eva Pereiro
- ALBA Synchrotron Light Source, Cerdanyola del Vallés, Barcelona08290, Spain
| | - Damien Faivre
- Aix-Marseille Université, Centre national de la recherche scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), UMR7265, Bioscience and biotechnology institute of Aix-Marseille (BIAM), Saint-Paul-lez-Durance13108, France
| | - Karim Benzerara
- Sorbonne Université, UMR CNRS 7590, Muséum national d'Histoire naturelle (MNHN), Institut de recherche pour le développement (IRD), Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), 75005Paris, France
| | - Caroline L. Monteil
- Aix-Marseille Université, Centre national de la recherche scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), UMR7265, Bioscience and biotechnology institute of Aix-Marseille (BIAM), Saint-Paul-lez-Durance13108, France
| | - Christopher T. Lefevre
- Aix-Marseille Université, Centre national de la recherche scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), UMR7265, Bioscience and biotechnology institute of Aix-Marseille (BIAM), Saint-Paul-lez-Durance13108, France
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7
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Vincent MS, Comas Hervada C, Sebban-Kreuzer C, Le Guenno H, Chabalier M, Kosta A, Guerlesquin F, Mignot T, McBride MJ, Cascales E, Doan T. Dynamic proton-dependent motors power type IX secretion and gliding motility in Flavobacterium. PLoS Biol 2022; 20:e3001443. [PMID: 35333857 PMCID: PMC8986121 DOI: 10.1371/journal.pbio.3001443] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 04/06/2022] [Accepted: 03/01/2022] [Indexed: 02/06/2023] Open
Abstract
Motile bacteria usually rely on external apparatus like flagella for swimming or pili for twitching. By contrast, gliding bacteria do not rely on obvious surface appendages to move on solid surfaces. Flavobacterium johnsoniae and other bacteria in the Bacteroidetes phylum use adhesins whose movement on the cell surface supports motility. In F. johnsoniae, secretion and helicoidal motion of the main adhesin SprB are intimately linked and depend on the type IX secretion system (T9SS). Both processes necessitate the proton motive force (PMF), which is thought to fuel a molecular motor that comprises the GldL and GldM cytoplasmic membrane proteins. Here, we show that F. johnsoniae gliding motility is powered by the pH gradient component of the PMF. We further delineate the interaction network between the GldLM transmembrane helices (TMHs) and show that conserved glutamate residues in GldL TMH2 are essential for gliding motility, although having distinct roles in SprB secretion and motion. We then demonstrate that the PMF and GldL trigger conformational changes in the GldM periplasmic domain. We finally show that multiple GldLM complexes are distributed in the membrane, suggesting that a network of motors may be present to move SprB along a helical path on the cell surface. Altogether, our results provide evidence that GldL and GldM assemble dynamic membrane channels that use the proton gradient to power both T9SS-dependent secretion of SprB and its motion at the cell surface. Motile bacteria usually rely on external apparatus like flagella or pili, but gliding bacteria do not rely on obvious surface appendages for their movement. This study shows that bacteria in the phylum Bacteroidetes use proton-dependent motors to power protein secretion and gliding motility.
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Affiliation(s)
- Maxence S. Vincent
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université – CNRS UMR7255, Marseille, France
| | - Caterina Comas Hervada
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université – CNRS UMR7255, Marseille, France
| | - Corinne Sebban-Kreuzer
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université – CNRS UMR7255, Marseille, France
| | - Hugo Le Guenno
- Microscopy Core Facility, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université, Marseille, France
| | - Maïalène Chabalier
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université – CNRS UMR7255, Marseille, France
| | - Artemis Kosta
- Microscopy Core Facility, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université, Marseille, France
| | - Françoise Guerlesquin
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université – CNRS UMR7255, Marseille, France
| | - Tâm Mignot
- Laboratoire de Chimie Bactérienne, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université – CNRS UMR7283, Marseille, France
| | - Mark J. McBride
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, United States of America
| | - Eric Cascales
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université – CNRS UMR7255, Marseille, France
- * E-mail: (EC); (TD)
| | - Thierry Doan
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université – CNRS UMR7255, Marseille, France
- * E-mail: (EC); (TD)
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8
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Bouteiller M, Gallique M, Bourigault Y, Kosta A, Hardouin J, Massier S, Konto-Ghiorghi Y, Barbey C, Latour X, Chane A, Feuilloley M, Merieau A. Crosstalk between the Type VI Secretion System and the Expression of Class IV Flagellar Genes in the Pseudomonas fluorescens MFE01 Strain. Microorganisms 2020; 8:microorganisms8050622. [PMID: 32344878 PMCID: PMC7286023 DOI: 10.3390/microorganisms8050622] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 04/16/2020] [Accepted: 04/23/2020] [Indexed: 11/16/2022] Open
Abstract
Type VI secretion systems (T6SSs) are contractile bacterial multiprotein nanomachines that enable the injection of toxic effectors into prey cells. The Pseudomonas fluorescens MFE01 strain has T6SS antibacterial activity and can immobilise competitive bacteria through the T6SS. Hcp1 (hemolysin co-regulated protein 1), a constituent of the T6SS inner tube, is involved in such prey cell inhibition of motility. Paradoxically, disruption of the hcp1 or T6SS contractile tail tssC genes results in the loss of the mucoid and motile phenotypes in MFE01. Here, we focused on the relationship between T6SS and flagella-associated motility. Electron microscopy revealed the absence of flagellar filaments for MFE01Δhcp1 and MFE01ΔtssC mutants. Transcriptomic analysis showed a reduction in the transcription of class IV flagellar genes in these T6SS mutants. However, transcription of fliA, the gene encoding the class IV flagellar sigma factor, was unaffected. Over-expression of fliA restored the motile and mucoid phenotypes in both MFE01Δhcp1+fliA, and MFE01ΔtssC+fliA and a fliA mutant displayed the same phenotypes as MFE01Δhcp1 and MFE01ΔtssC. Moreover, the FliA anti-sigma factor FlgM was not secreted in the T6SS mutants, and flgM over-expression reduced both motility and mucoidy. This study provides arguments to unravel the crosstalk between T6SS and motility.
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Affiliation(s)
- Mathilde Bouteiller
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (M.G.); (Y.B.); (Y.K.-G.); (C.B.); (X.L.); (A.C.); (M.F.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, F-76821 Mont-Saint-Aignan, France
| | - Mathias Gallique
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (M.G.); (Y.B.); (Y.K.-G.); (C.B.); (X.L.); (A.C.); (M.F.)
- Meakins-Christie laboratories, Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada
- Department of Chemical Engineering, McGill University, Montreal, QC H3A 0C5, Canada
| | - Yvann Bourigault
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (M.G.); (Y.B.); (Y.K.-G.); (C.B.); (X.L.); (A.C.); (M.F.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, F-76821 Mont-Saint-Aignan, France
| | - Artemis Kosta
- Plateforme de Microscopie de l’Institut de Microbiologie de la Méditerranée, IMM, Institut de Microbiologie, FR3479, Campus CNRS, 13402 Marseille cedex 20, France;
| | - Julie Hardouin
- Polymers, Biopolymers, Surface Laboratory, UMR 6270 CNRS, University of Rouen, F-76821 Mont-Saint-Aignan cedex, France; (J.H.); (S.M.)
- PISSARO Proteomics Facility, Université de Rouen, F-76821 Mont-Saint-Aignan, France
| | - Sebastien Massier
- Polymers, Biopolymers, Surface Laboratory, UMR 6270 CNRS, University of Rouen, F-76821 Mont-Saint-Aignan cedex, France; (J.H.); (S.M.)
- PISSARO Proteomics Facility, Université de Rouen, F-76821 Mont-Saint-Aignan, France
| | - Yoan Konto-Ghiorghi
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (M.G.); (Y.B.); (Y.K.-G.); (C.B.); (X.L.); (A.C.); (M.F.)
| | - Corinne Barbey
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (M.G.); (Y.B.); (Y.K.-G.); (C.B.); (X.L.); (A.C.); (M.F.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, F-76821 Mont-Saint-Aignan, France
| | - Xavier Latour
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (M.G.); (Y.B.); (Y.K.-G.); (C.B.); (X.L.); (A.C.); (M.F.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, F-76821 Mont-Saint-Aignan, France
| | - Andréa Chane
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (M.G.); (Y.B.); (Y.K.-G.); (C.B.); (X.L.); (A.C.); (M.F.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, F-76821 Mont-Saint-Aignan, France
| | - Marc Feuilloley
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (M.G.); (Y.B.); (Y.K.-G.); (C.B.); (X.L.); (A.C.); (M.F.)
| | - Annabelle Merieau
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (M.G.); (Y.B.); (Y.K.-G.); (C.B.); (X.L.); (A.C.); (M.F.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, F-76821 Mont-Saint-Aignan, France
- Correspondence:
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9
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Crepin A, Kučerová Z, Kosta A, Durand E, Caffarri S. Isolation and characterization of a large photosystem I-light-harvesting complex II supercomplex with an additional Lhca1-a4 dimer in Arabidopsis. Plant J 2020; 102:398-409. [PMID: 31811681 DOI: 10.1111/tpj.14634] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/08/2019] [Accepted: 11/26/2019] [Indexed: 05/24/2023]
Abstract
The biological conversion of light energy into chemical energy is performed by a flexible photosynthetic machinery located in the thylakoid membranes. Photosystems I and II (PSI and PSII) are the two complexes able to harvest light. PSI is the last complex of the electron transport chain and is composed of multiple subunits: the proteins building the catalytic core complex that are well conserved between oxygenic photosynthetic organisms, and, in green organisms, the membrane light-harvesting complexes (Lhc) necessary to increase light absorption. In plants, four Lhca proteins (Lhca1-4) make up the antenna system of PSI, which can be further extended to optimize photosynthesis by reversible binding of LHCII, the main antenna complex of photosystem II. Here, we used biochemistry and electron microscopy in Arabidopsis to reveal a previously unknown supercomplex of PSI with LHCII that contains an additional Lhca1-a4 dimer bound on the PsaB-PsaI-PsaH side of the complex. This finding contradicts recent structural studies suggesting that the presence of an Lhca dimer at this position is an exclusive feature of algal PSI. We discuss the features of the additional Lhca dimer in the large plant PSI-LHCII supercomplex and the differences with the algal PSI. Our work provides further insights into the intricate structural plasticity of photosystems.
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Affiliation(s)
- Aurélie Crepin
- Aix Marseille Université, CEA, CNRS, Biosciences and Biotechnologies Institute of Aix-Marseille (BIAM), Equipe de Luminy de Génétique et Biophysique des Plantes, 13009, Marseille, France
- Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, Opatovický mlýn, 379 81, Třeboň, Czech Republic
| | - Zuzana Kučerová
- Aix Marseille Université, CEA, CNRS, Biosciences and Biotechnologies Institute of Aix-Marseille (BIAM), Equipe de Luminy de Génétique et Biophysique des Plantes, 13009, Marseille, France
- Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, 78371, Olomouc, Czech Republic
| | - Artemis Kosta
- Microscopy Core Facility, Institut de Microbiologie de la Méditerranée (IMM), FR3479, CNRS, Aix-Marseille University, Marseille, France
| | - Eric Durand
- Aix-Marseille Université, CNRS, Institut de Microbiologie de la Méditerranée (IMM), Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM), UMR 7255, 13402, Marseille cedex 09, France
| | - Stefano Caffarri
- Aix Marseille Université, CEA, CNRS, Biosciences and Biotechnologies Institute of Aix-Marseille (BIAM), Equipe de Luminy de Génétique et Biophysique des Plantes, 13009, Marseille, France
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10
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Qian X, Santini C, Kosta A, Menguy N, Le Guenno H, Zhang W, Li J, Chen Y, Liu J, Alberto F, Espinosa L, Xiao T, Wu L. Juxtaposed membranes underpin cellular adhesion and display unilateral cell division of multicellular magnetotactic prokaryotes. Environ Microbiol 2020; 22:1481-1494. [DOI: 10.1111/1462-2920.14710] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 06/09/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Xin‐Xin Qian
- Aix Marseille University, CNRS, LCB Marseille 13402 France
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms (LIA‐MagMC), CNRS‐CAS Marseille 13402 France
| | - Claire‐Lise Santini
- Aix Marseille University, CNRS, LCB Marseille 13402 France
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms (LIA‐MagMC), CNRS‐CAS Marseille 13402 France
| | - Artemis Kosta
- Microscopy Core Facility, FR3479 IMM, CNRS, Aix Marseille University Marseille France
| | - Nicolas Menguy
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms (LIA‐MagMC), CNRS‐CAS Marseille 13402 France
- Sorbonne Université, UMR CNRS 7590, Muséum National d'Histoire Naturelle, IRD, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC 75005 Paris France
| | - Hugo Le Guenno
- Microscopy Core Facility, FR3479 IMM, CNRS, Aix Marseille University Marseille France
| | - Wenyan Zhang
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms (LIA‐MagMC), CNRS‐CAS Marseille 13402 France
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences Qingdao 266071 China
| | - Jinhua Li
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms (LIA‐MagMC), CNRS‐CAS Marseille 13402 France
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences Beijing 100029 China
| | - Yi‐Ran Chen
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms (LIA‐MagMC), CNRS‐CAS Marseille 13402 France
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences Qingdao 266071 China
| | - Jia Liu
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms (LIA‐MagMC), CNRS‐CAS Marseille 13402 France
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences Qingdao 266071 China
| | - François Alberto
- Aix Marseille University, CNRS, LCB Marseille 13402 France
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms (LIA‐MagMC), CNRS‐CAS Marseille 13402 France
| | - Leon Espinosa
- Aix Marseille University, CNRS, LCB Marseille 13402 France
| | - Tian Xiao
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms (LIA‐MagMC), CNRS‐CAS Marseille 13402 France
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences Qingdao 266071 China
| | - Long‐Fei Wu
- Aix Marseille University, CNRS, LCB Marseille 13402 France
- International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms (LIA‐MagMC), CNRS‐CAS Marseille 13402 France
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11
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Jensen EL, Clement R, Kosta A, Maberly SC, Gontero B. A new widespread subclass of carbonic anhydrase in marine phytoplankton. ISME J 2019; 13:2094-2106. [PMID: 31024153 PMCID: PMC6776030 DOI: 10.1038/s41396-019-0426-8] [Citation(s) in RCA: 125] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 03/28/2019] [Accepted: 03/30/2019] [Indexed: 11/09/2022]
Abstract
Most aquatic photoautotrophs depend on CO2-concentrating mechanisms (CCMs) to maintain productivity at ambient concentrations of CO2, and carbonic anhydrase (CA) plays a key role in these processes. Here we present different lines of evidence showing that the protein LCIP63, identified in the marine diatom Thalassiosira pseudonana, is a CA. However, sequence analysis showed that it has a low identity with any known CA and therefore belongs to a new subclass that we designate as iota-CA. Moreover, LCIP63 unusually prefers Mn2+ to Zn2+ as a cofactor, which is potentially of ecological relevance since Mn2+ is more abundant than Zn2+ in the ocean. LCIP63 is located in the chloroplast and only expressed at low concentrations of CO2. When overexpressed using biolistic transformation, the rate of photosynthesis at limiting concentrations of dissolved inorganic carbon increased, confirming its role in the CCM. LCIP63 homologs are present in the five other sequenced diatoms and in other algae, bacteria, and archaea. Thus LCIP63 is phylogenetically widespread but overlooked. Analysis of the Tara Oceans database confirmed this and showed that LCIP63 is widely distributed in marine environments and is therefore likely to play an important role in global biogeochemical carbon cycling.
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Affiliation(s)
- Erik L Jensen
- Aix Marseille Univ, CNRS, BIP, UMR 7281, IMM, FR3479, 31 Chemin J. Aiguier, 13402, Marseille Cedex 20, France
| | - Romain Clement
- Aix Marseille Univ, CNRS, BIP, UMR 7281, IMM, FR3479, 31 Chemin J. Aiguier, 13402, Marseille Cedex 20, France
| | - Artemis Kosta
- Microscopy Core Facility, Aix Marseille Univ, CNRS, IMM, FR3479, 31 Chemin J. Aiguier, 13402, Marseille Cedex 20, France
| | - Stephen C Maberly
- Lake Ecosystems Group, Centre for Ecology & Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, LA1 4AP, UK
| | - Brigitte Gontero
- Aix Marseille Univ, CNRS, BIP, UMR 7281, IMM, FR3479, 31 Chemin J. Aiguier, 13402, Marseille Cedex 20, France.
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12
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van Lis R, Popek M, Couté Y, Kosta A, Drapier D, Nitschke W, Atteia A. Concerted Up-regulation of Aldehyde/Alcohol Dehydrogenase (ADHE) and Starch in Chlamydomonas reinhardtii Increases Survival under Dark Anoxia. J Biol Chem 2016; 292:2395-2410. [PMID: 28007962 DOI: 10.1074/jbc.m116.766048] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [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: 11/21/2016] [Revised: 12/21/2016] [Indexed: 11/06/2022] Open
Abstract
Aldehyde/alcohol dehydrogenases (ADHEs) are bifunctional enzymes that commonly produce ethanol from acetyl-CoA with acetaldehyde as intermediate and play a key role in anaerobic redox balance in many fermenting bacteria. ADHEs are also present in photosynthetic unicellular eukaryotes, where their physiological role and regulation are, however, largely unknown. Herein we provide the first molecular and enzymatic characterization of the ADHE from the photosynthetic microalga Chlamydomonas reinhardtii Purified recombinant ADHE catalyzed the reversible NADH-mediated interconversions of acetyl-CoA, acetaldehyde, and ethanol but seemed to be poised toward the production of ethanol from acetaldehyde. Phylogenetic analysis of the algal fermentative enzyme supports a vertical inheritance from a cyanobacterial-related ancestor. ADHE was located in the chloroplast, where it associated in dimers and higher order oligomers. Electron microscopy analysis of ADHE-enriched stromal fractions revealed fine spiral structures, similar to bacterial ADHE spirosomes. Protein blots showed that ADHE is regulated under oxic conditions. Up-regulation is observed in cells exposed to diverse physiological stresses, including zinc deficiency, nitrogen starvation, and inhibition of carbon concentration/fixation capacity. Analyses of the overall proteome and fermentation profiles revealed that cells with increased ADHE abundance exhibit better survival under dark anoxia. This likely relates to the fact that greater ADHE abundance appeared to coincide with enhanced starch accumulation, which might reflect ADHE-mediated anticipation of anaerobic survival.
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Affiliation(s)
- Robert van Lis
- From the Aix Marseille Université, CNRS, BIP-UMR 7281, 13402 Marseille, France.,LBE, INRA, 11100 Narbonne, France
| | - Marion Popek
- From the Aix Marseille Université, CNRS, BIP-UMR 7281, 13402 Marseille, France
| | - Yohann Couté
- the Université Grenoble Alpes, BIG-BGE, 38000 Grenoble, France.,the Commissariat à l'Energie Atomique, BIG-BGE, 38000 Grenoble, France.,INSERM, BGE, 38000 Grenoble, France
| | - Artemis Kosta
- the Microscopy Core Facility, FR3479 Institut de Microbiologie de la Méditerranée, 13402 Marseille cedex 20, France, and
| | - Dominique Drapier
- the Institut de Biologie Physico-Chimique, UMR7141 CNRS-UPMC, 75005 Paris, France
| | - Wolfgang Nitschke
- From the Aix Marseille Université, CNRS, BIP-UMR 7281, 13402 Marseille, France
| | - Ariane Atteia
- From the Aix Marseille Université, CNRS, BIP-UMR 7281, 13402 Marseille, France,
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13
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Collins JW, Chervaux C, Raymond B, Derrien M, Brazeilles R, Kosta A, Chambaud I, Crepin VF, Frankel G. Fermented dairy products modulate Citrobacter rodentium-induced colonic hyperplasia. J Infect Dis 2014; 210:1029-41. [PMID: 24706936 PMCID: PMC4157696 DOI: 10.1093/infdis/jiu205] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
We evaluated the protective effects of fermented dairy products (FDPs) in an infection model, using the mouse pathogen Citrobacter rodentium (CR). Treatment of mice with FDP formulas A, B, and C or a control product did not affect CR colonization, organ specificity, or attaching and effacing lesion formation. Fermented dairy product A (FDP-A), but neither the supernatant from FDP-A nor β-irradiated (IR) FDP-A, caused a significant reduction in colonic crypt hyperplasia and CR-associated pathology. Profiling the gut microbiota revealed that IR-FDP-A promoted higher levels of phylotypes belonging to Alcaligenaceae and a decrease in Lachnospiraceae (Ruminococcus) during CR infection. Conversely, FDP-A prevented a decrease in Ruminococcus and increased Turicibacteraceae (Turicibacter). Importantly, loss of Ruminococcus and Turicibacter has been associated with susceptibility to dextran sodium sulfate-induced colitis. Our results demonstrate that viable bacteria in FDP-A reduced CR-induced colonic crypt hyperplasia and prevented the loss of key bacterial genera that may contribute to disease pathology.
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Affiliation(s)
- James W Collins
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, United Kingdom
| | | | - Benoit Raymond
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, United Kingdom
| | - Muriel Derrien
- Danone Nutricia Research, Centre Daniel Carasso, Palaiseau
| | | | - Artemis Kosta
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, United Kingdom
| | | | - Valerie F Crepin
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, United Kingdom
| | - Gad Frankel
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, United Kingdom
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14
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Collins JW, Akin AR, Kosta A, Zhang N, Tangney M, Francis KP, Frankel G. Pre-treatment with Bifidobacterium breve UCC2003 modulates Citrobacter rodentium-induced colonic inflammation and organ specificity. Microbiology (Reading) 2012; 158:2826-2834. [PMID: 22902730 PMCID: PMC3541765 DOI: 10.1099/mic.0.060830-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Citrobacter rodentium, which colonizes the gut mucosa via formation of attaching and effacing (A/E) lesions, causes transmissible colonic hyperplasia. The aim of this study was to evaluate whether prophylactic treatment with Bifidobacterium breve UCC2003 can improve the outcome of C. rodentium infection. Six-week-old albino C57BL/6 mice were pre-treated for 3 days with B. breve, challenged with bioluminescent C. rodentium and administered B. breve or PBS-C for 8 days post-infection; control mice were either administered B. breve and mock-infected with PBS, or mock-treated with PBS-C and mock-infected with PBS. C. rodentium colonization was monitored by bacterial enumeration from faeces and by a combination of both 2D bioluminescence imaging (BLI) and composite 3D diffuse light imaging tomography with µCT imaging (DLIT-µCT). At day 8 post-infection, colons were removed and assessed for crypt hyperplasia, histology by light microscopy, bacterial colonization by immunofluorescence, and A/E lesion formation by electron microscopy. Prophylactic administration of B. breve did not prevent C. rodentium colonization or A/E lesion formation. However, this treatment did alter C. rodentium distribution within the large intestine and significantly reduced colonic crypt hyperplasia at the peak of bacterial infection. These results show that B. breve could not competitively exclude C. rodentium, but reduced pathogen-induced colonic inflammation.
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Affiliation(s)
- James W Collins
- Centre for Molecular Bacteriology and Infection, Division of Cell and Molecular Biology, Flowers Building, Imperial College London, London SW7 2AZ, UK
| | - Ali R Akin
- Caliper - a PerkinElmer Company, Alameda, CA 94501, USA
| | - Artemis Kosta
- Centre for Molecular Bacteriology and Infection, Division of Cell and Molecular Biology, Flowers Building, Imperial College London, London SW7 2AZ, UK
| | - Ning Zhang
- Caliper - a PerkinElmer Company, Alameda, CA 94501, USA
| | - Mark Tangney
- Cork Cancer Research Centre, BioSciences Institute, University College Cork, Cork, Ireland
| | | | - Gad Frankel
- Centre for Molecular Bacteriology and Infection, Division of Cell and Molecular Biology, Flowers Building, Imperial College London, London SW7 2AZ, UK
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15
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Giusti C, Luciani MF, Klein G, Aubry L, Tresse E, Kosta A, Golstein P. Necrotic cell death: From reversible mitochondrial uncoupling to irreversible lysosomal permeabilization. Exp Cell Res 2008; 315:26-38. [PMID: 18951891 DOI: 10.1016/j.yexcr.2008.09.028] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2008] [Revised: 09/24/2008] [Accepted: 09/24/2008] [Indexed: 11/19/2022]
Abstract
Dictyostelium atg1- mutant cells provide an experimentally and genetically favorable model to study necrotic cell death (NCD) with no interference from apoptosis or autophagy. In such cells subjected to starvation and cAMP, induction by the differentiation-inducing factor DIF or by classical uncouplers led within minutes to mitochondrial uncoupling, which causally initiated NCD. We now report that (1) in this model, NCD included a mitochondrial-lysosomal cascade of events, (2) mitochondrial uncoupling and therefore initial stages of death showed reversibility for a surprisingly long time, (3) subsequent lysosomal permeabilization could be demonstrated using Lysosensor blue, acridin orange, Texas red-dextran and cathepsin B substrate, (4) this lysosomal permeabilization was irreversible, and (5) the presence of the uncoupler was required to maintain mitochondrial lesions but also to induce lysosomal lesions, suggesting that signaling from mitochondria to lysosomes must be sustained by the continuous presence of the uncoupler. These results further characterized the NCD pathway in this priviledged model, contributed to a definition of NCD at the lysosomal level, and suggested that in mammalian NCD even late reversibility attempts by removal of the inducer may be of therapeutic interest.
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Affiliation(s)
- Corinne Giusti
- Centre d'Immunologie de Marseille-Luminy (CIML), Faculté des Sciences de Luminy, Aix Marseille Université, Marseille F-13288, France
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16
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Kosta A, Luciani MF, Geerts WJ, Golstein P. Marked mitochondrial alterations upon starvation without cell death, caspases or Bcl-2 family members. Biochimica et Biophysica Acta (BBA) - Molecular Cell Research 2008; 1783:2013-9. [DOI: 10.1016/j.bbamcr.2008.06.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Revised: 06/03/2008] [Accepted: 06/09/2008] [Indexed: 10/21/2022]
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17
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Abstract
Autophagic cell death in Dictyostelium can be dissociated into a starvation-induced sensitization stage and a death induction stage. A UDP-glucose pyrophosphorylase (ugpB) mutant and a glycogen synthase (glcS) mutant shared the same abnormal phenotype. In vitro, upon starvation alone mutant cells showed altered contorted morphology, indicating that the mutations affected the pre-death sensitization stage. Upon induction of cell death, most of these mutant cells underwent death without vacuolization, distinct from either autophagic or necrotic cell death. Autophagy itself was not grossly altered as shown by conventional and electron microscopy. Exogenous glycogen or maltose could complement both ugpB(-) and glcS(-) mutations, leading back to autophagic cell death. The glcS(-) mutation could also be complemented by 2-deoxyglucose that cannot undergo glycolysis. In agreement with the in vitro data, upon development glcS(-) stalk cells died but most were not vacuolated. We conclude that a UDP-glucose derivative (such as glycogen or maltose) plays an essential energy-independent role in autophagic cell death.
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Affiliation(s)
- Emilie Tresse
- Centre d'Immunologie de Marseille-Luminy (CIML), Faculté des Sciences de Luminy, Aix Marseille Université, INSERM U631, CNRS UMR6102, Marseille, France
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18
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Abstract
Non-apoptotic cell death types can be conveniently studied in Dictyostelium discoideum, an exceptionally favorable model not only because of its well-known genetic and experimental advantages, but also because in Dictyostelium there is no apoptosis machinery that could interfere with non-apoptotic cell death. We show here how to conveniently demonstrate, assess, and study these non-apoptotic cell death types. These can be generated by use of modifications of the monolayer technique of Rob Kay et al., and either wild-type HMX44A Dictyostelium cells, leading to autophagic cell death, or the corresponding atg1- autophagy gene mutant cells, leading to necrotic cell death. Methods to follow these non-apoptotic cell death types qualitatively and quantitatively will be reported.
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Affiliation(s)
- Corinne Giusti
- Centre d'Immunologie INSERM-CNRS-Univ.Medit. de Marseille-Luminy, Marseille, France
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20
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Abstract
The signaling pathways governing pathophysiologically important autophagic (ACD) and necrotic (NCD) cell death are not entirely known. In the Dictyostelium eukaryote model, which benefits from both unique analytical and genetic advantages and absence of potentially interfering apoptotic machinery, the differentiation factor DIF leads from starvation-induced autophagy to ACD, or, if atg1 is inactivated, to NCD. Here, through random insertional mutagenesis, we found that inactivation of the iplA gene, the only gene encoding an inositol 1,4,5-trisphosphate receptor (IP3R) in this organism, prevented ACD. The IP3R is a ligand-gated channel governing Ca(2+) efflux from endoplasmic reticulum stores to the cytosol. Accordingly, Ca(2+)-related drugs also affected DIF signaling leading to ACD. Thus, in this system, a main pathway signaling ACD requires IP3R and further Ca(2+)-dependent steps. This is one of the first insights in the molecular understanding of a signaling pathway leading to autophagic cell death.
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Affiliation(s)
- David Lam
- Centre d'Immunologie de Marseille-Luminy, Institut National de la Santé et de la Recherche Médicale U631, and Centre National de la Recherche Scientifique Unité Mixte de Recherche 6102, Aix Marseille Université, Marseille, France
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21
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Abstract
Among unusual models to study cell death mechanisms, the protist Dictyostelium is remarkable because of its strategic phylogenetic position, with early emergence among eukaryotes and unicellular/multicellular transition, and its very favorable experimental and genetic flexibility. Dictyostelium shows developmental vacuolar cell death, and in vitro monolayer approaches revealed both an autophagic vacuolar and a necrotic type of cell death. These are described in some detail, as well as implications and future prospects.
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Affiliation(s)
- Emilie Tresse
- Centre d'Immunologie de Marseille-Luminy, Université de la Méditerranée, Case 906, 13288 Marseille Cedex 9, France
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22
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Abstract
In this chapter, we describe how to conveniently demonstrate, assess, and study cell death in Dictyostelium through simple cell culture, clonogenic tests, and photonic (with the help of staining techniques) and electronic microscopy. Cell death can be convniently generated using minor modifications of the monolayer technique of Rob Kay et al., and either wild-type HMX44A Dictyostelium cells or the corresponding atg1- autophagy gene mutant cells. Methods to follow cell death qualitatively and quantitatively facilitate detailed studies of vacuolar death in wild-type cells and of nonvacuolar, "condensed" death in atg1- mutant cells.
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Affiliation(s)
- Artemis Kosta
- Centre d'Immunologie INSERM-CNRS-Univ. Medit. de Marseille-Luminy, France
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Abstract
While necrotic cell death is attracting considerable interest, its molecular bases are still poorly understood. Investigations in simple biological models, taken for instance outside the animal kingdom, may benefit from less interference from other cell death mechanisms and from better experimental accessibility, while providing phylogenetic information. Can necrotic cell death occur outside the animal kingdom? In the protist Dictyostelium, developmental stimuli induced in an autophagy mutant a stereotyped sequence of events characteristic of necrotic cell death. This sequence included swift mitochondrial uncoupling with mitochondrial 2',7'-dichlorofluorescein diacetate fluorescence, ATP depletion and increased oxygen consumption. This was followed by perinuclear clustering of dilated mitochondria. Rapid plasma membrane rupture then occurred, which was evidenced by time-lapse videos and quantified by FACS. Of additional interest, developmental stimuli and classical mitochondrial uncouplers triggered a similar sequence of events, and exogenous glucose delayed plasma membrane rupture in a nonglycolytic manner. The occurrence of necrotic cell death in the protist Dictyostelium (1) provides a very favorable model for further study of this type of cell death, and (2) strongly suggests that the mechanism underlying necrotic cell death was present in an ancestor common to the Amoebozoa protists and to animals and has been conserved in evolution.
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Affiliation(s)
- C Laporte
- Centre d'Immunologie de Marseille-Luminy, Université de la Méditerranée, Case 906, Parc Scientifique de Luminy, 13288 Marseille Cedex 9, France
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Kosta A, Roisin-Bouffay C, Luciani MF, Otto GP, Kessin RH, Golstein P. Autophagy Gene Disruption Reveals a Non-vacuolar Cell Death Pathway in Dictyostelium. J Biol Chem 2004; 279:48404-9. [PMID: 15358773 DOI: 10.1074/jbc.m408924200] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Types of cell death include apoptosis, necrosis, and autophagic cell death. The latter can be defined as death of cells containing autophagosomes, autophagic bodies, and/or vacuoles. Are autophagy and vacuolization causes, consequences, or side effects in cell death with autophagy? Would control of autophagy suffice to control this type of cell death? We disrupted the atg1 autophagy gene in Dictyostelium discoideum, a genetically tractable model for developmental autophagic vacuolar cell death. The procedure that induced autophagy, vacuolization, and death in wild-type cells led in atg1 mutant cells to impaired autophagy and to no vacuolization, demonstrating that atg1 is required for vacuolization. Unexpectedly, however, cell death still took place, with a non-vacuolar and centrally condensed morphology. Thus, a cell death mechanism that does not require vacuolization can operate in this cell death model showing conspicuous vacuolization. The revelation of non-vacuolar cell death in this protist by autophagy gene disruption is reminiscent of caspase inhibition revealing necrotic cell death in animal cells. Thus, hidden alternative cell death pathways may be found across kingdoms and for diverse types of cell death.
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Affiliation(s)
- Artemis Kosta
- Centre d'Immunologie INSERM/CNRS/Université de la Mediterranée de Marseille-Luminy, Case 906, Avenue de Luminy, 13288 Marseille Cedex 9, France
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Thomopoulos GN, Shori DK, Asking B, Kosta A, Dimopoulou A, Paterson K, Hartley R, Colledge WH. Ultrastructural changes in exocrine tissues of a DeltaF-508 CFTR mouse model. Pflugers Arch 2002; 443 Suppl 1:S28-35. [PMID: 11845299 DOI: 10.1007/s004240100640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Cystic fibrosis (CF) is characterized by abnormal secretion from epithelial cells. We wanted to detect changes in the ultrastructural characteristics of cells within a number of exocrine tissues, including the colon, submandibular and parotid salivary glands of DeltaF-508 CFTR animals. Therefore, in the present study a DeltaF-508 CFTR mouse model was compared to control, by applying conventional and complex carbohydrates staining techniques to tissue sections at the electron microscope level. The colon of DeltaF-508 CFTR mice contained thick mucous secretions that harbored many bacteria, along with cytoplasmic fragments and leukocytes. Leukocytes were also seen to infiltrate the cytoplasm of goblet cells. Tissues were taken before, 10 min after isoprenaline, and 30 min after a further injection of methacholine. In the submandibular gland, there is limited secretory activity after isoprenaline treatment, and this increases further with methacholine treatment. Depletion of the secretory granules of acinar cells is observed, following the combined isoprenaline and methacholine treatment, but no significant changes in granule numbers occurred in granular tubule cells. Glycogen, abundant before treatment, is reduced within 10 min of isoprenaline treatment and is completely exhausted by 30 min, especially in the convoluted granular tubule cells. A few secretory granules in acinar and in granular tubule cells of the DeltaF-508 CFTR submandibular glands displayed two electron densities. The secretory responses of the parotid gland cells were similar to those in submandibular gland cells, except that in these DeltaF-508 CFTR cells, secretory granules appeared more polymorphic in structure than those found in control animals.
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Affiliation(s)
- G N Thomopoulos
- Aristotle University, School of Sciences, Department of Biology, Thessaloniki, 540 06, Greece.
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26
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Kosta A, Thomopoulos GN. Intranuclear virus-like particles of a Drosophila hybrid. J Submicrosc Cytol Pathol 2002; 34:177-86. [PMID: 12117278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Intranuclear virus-like particles (VLPs) have been observed in different cell lines and adult tissues of Drosophila. In the present study, intranuclear VLPs have been found in larval tissues (salivary glands, midgut, fat body) as well as in adult tissues (midgut, genitals, fat body) of a rare interspecific hybrid (D. mauritiana x D. melanogaster) called 'mame'. The intranuclear VLPs were round or slightly elliptical with a diameter of 30 nm, and they were found mainly in highly organised clusters, forming large crystalline arrays, near the nucleolus and the polycene chromosomes. These particles were never observed in the cytoplasm of any mame's tissue. A few VLPs were also seen in the corresponding tissues of D. melanogaster, but they were never observed in any tissue of D. mauritiana. There is the intriguing possibility that these VLPs are related to transposable elements and probably contribute to the speciation process, in an unknown, so far, manner.
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Affiliation(s)
- A Kosta
- Department of Biology, Aristotle University School of Sciences, Thessaloniki, Greece
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27
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Abstract
Is there a preferred hemispheric canonical view of a concept? We investigated this question in a natural superordinate category membership decision task using a hemifield paradigm. Participants had to decide whether or not an image of an object lateralized in the left (LVF) or right (RVF) visual half-field is a member of a predesignated superordinate category. The objects represented high, medium, or low typicality levels, and each object had six different perspective views (front, front-right, front-left, side, back-left, and back-right). The latency responses revealed a significant interaction of Hemi Field X View X Typicality (there wasno hemifield difference in accuracy). The findings confirm the presence of asymmetry in stored concepts in long-term memory and suggest, in addition, a hemispheric canonical view of these concepts, a view strongly related to typicality level.
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Affiliation(s)
- D W Zaidel
- Department of Psychology, University of California, Los Angeles, USA
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28
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Kosta A, Dimopoulou K, Drosou V, Thomopoulos GN. Glycogen distribution in the larval salivary gland cells during the development of
Drosophila melanogaster
and
Drosophila auraria
: an ultrastructural cytochemical study. J Zool (1987) 2000. [DOI: 10.1111/j.1469-7998.2000.tb00593.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Artemis Kosta
- Aristotle University, School of Sciences, Department of Biology, 540 06 Thessaloniki, Greece
| | - Katerina Dimopoulou
- Aristotle University, School of Sciences, Department of Biology, 540 06 Thessaloniki, Greece
| | - Victoria Drosou
- Aristotle University, School of Sciences, Department of Biology, 540 06 Thessaloniki, Greece
| | - George N. Thomopoulos
- Aristotle University, School of Sciences, Department of Biology, 540 06 Thessaloniki, Greece
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