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Cardoso SM, Empadinhas N. The Microbiome-Mitochondria Dance in Prodromal Parkinson's Disease. Front Physiol 2018; 9:471. [PMID: 29867531 PMCID: PMC5954091 DOI: 10.3389/fphys.2018.00471] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 04/16/2018] [Indexed: 12/22/2022] Open
Abstract
The brain is an immunologically active organ where neurons and glia cells orchestrate complex innate immune responses against infections and injuries. Neuronal responses involve Toll-like or Nod-like receptors and the secretion of antimicrobial peptides and cytokines. The endosymbiotic theory for the evolutionary origin of mitochondria from primitive bacteria, suggests that they may have also retained the capacity to activate neuronal innate immunity. In fact, it was shown that mitochondrial damage-associated molecular patterns could signal and activate innate immunity and inflammation. Moreover, the mitochondrial cascade hypothesis for sporadic Parkinson’s disease (PD) argues that altered mitochondrial metabolism and function can drive neurodegeneration. Additionally, a neuroinflammatory signature with increased levels of pro-inflammatory mediators in PD affected brain areas was recently detected. Herein, we propose that a cascade of events initiating in a dysbiotic gut microbiome drive the production of toxins or antibiotics that target and damage mitochondria. This in turn activates neuronal innate immunity and triggers sterile inflammation phenomena that culminate in the neurodegenerative processes observed in the enteric and in the central nervous systems and that ultimately lead to Parkinson’s disease.
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Affiliation(s)
- Sandra M Cardoso
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Institute of Cellular and Molecular Biology, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Nuno Empadinhas
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
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52
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Mitochondria Restrict Growth of the Intracellular Parasite Toxoplasma gondii by Limiting Its Uptake of Fatty Acids. Cell Metab 2018; 27:886-897.e4. [PMID: 29617646 DOI: 10.1016/j.cmet.2018.02.018] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Revised: 01/05/2018] [Accepted: 02/20/2018] [Indexed: 01/27/2023]
Abstract
How intracellular pathogens acquire essential non-diffusible host metabolites and whether the host cell counteracts the siphoning of these nutrients by its invaders are open questions. Here we show that host mitochondria fuse during infection by the intracellular parasite Toxoplasma gondii to limit its uptake of fatty acids (FAs). A combination of genetics and imaging of FA trafficking indicates that Toxoplasma infection triggers lipophagy, the autophagy of host lipid droplets (LDs), to secure cellular FAs essential for its proliferation. Indeed, Toxoplasma FA siphoning and growth are reduced in host cells genetically deficient for autophagy or triglyceride depots. Conversely, Toxoplasma FA uptake and proliferation are increased in host cells lacking mitochondrial fusion, required for efficient mitochondrial FA oxidation, or where mitochondrial FA oxidation is pharmacologically inhibited. Thus, mitochondrial fusion can be regarded as a cellular defense mechanism against intracellular parasites, by limiting Toxoplasma access to host nutrients liberated by lipophagy.
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53
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Mitochondrial fragmentation affects neither the sensitivity to TNFα-induced apoptosis of Brucella-infected cells nor the intracellular replication of the bacteria. Sci Rep 2018; 8:5173. [PMID: 29581535 PMCID: PMC5979954 DOI: 10.1038/s41598-018-23483-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 03/13/2018] [Indexed: 01/18/2023] Open
Abstract
Mitochondria are complex organelles that participate in many cellular functions, ranging from ATP production to immune responses against viruses and bacteria. This integration of a plethora of functions within a single organelle makes mitochondria a very attractive target to manipulate for intracellular pathogens. We characterised the crosstalk that exists between Brucella abortus, the causative agent of brucellosis, and the mitochondria of infected cells. Brucella replicates in a compartment derived from the endoplasmic reticulum (ER) and modulates ER functionality by activating the unfolded protein response. However, the impact of Brucella on the mitochondrial population of infected cells still requires a systematic study. We observed physical contacts between Brucella containing vacuoles and mitochondria. We also found that B. abortus replication is independent of mitochondrial oxidative phosphorylation and that mitochondrial reactive oxygen species do not participate to the control of B. abortus infection in vitro. We demonstrated that B. abortus and B. melitensis induce a drastic mitochondrial fragmentation at 48 hours post-infection in different cell types, including myeloid and non-myeloid cells. This fragmentation is DRP1-independent and might be caused by a deficit of mitochondrial fusion. However, mitochondrial fragmentation does not change neither Brucella replication efficiency, nor the susceptibility of infected cells to TNFα-induced apoptosis.
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54
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Zemirli N, Morel E, Molino D. Mitochondrial Dynamics in Basal and Stressful Conditions. Int J Mol Sci 2018; 19:ijms19020564. [PMID: 29438347 PMCID: PMC5855786 DOI: 10.3390/ijms19020564] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 01/30/2018] [Accepted: 02/07/2018] [Indexed: 12/26/2022] Open
Abstract
The historical role of mitochondria resides in converting the energy released during the oxidation of macromolecules (carbohydrates, lipids and proteins) into adenosine tri-phosphate, a major form of chemically stored energy which sustains cell growth and homeostasis. Beyond this role in bioenergetics regulation, mitochondria play a role in several other cellular processes including lipid metabolism, cellular calcium homeostasis, autophagy and immune responses. Furthermore, mitochondria are highly dynamic organelles: as all other cellular endomembranes, they are continuously moving along cytoskeleton, and, most importantly, they constantly interact one with each other by membrane tethering, fusion and fission. This review aims to highlight the tight correlation between the morphodynamics of mitochondria and their biological function(s), in physiological as well as stress conditions, in particular nutrient deprivation, pathogen attack and some human diseases. Finally, we emphasize some crosstalk between the fusion/fission machinery and the autophagy pathway to ending on some speculative hypothesis to inspire future research in the field.
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Affiliation(s)
- Naima Zemirli
- Institut Necker-Enfants Malades (INEM), INSERM U1151-CNRS UMR 8253, Paris F-75014, France.
- Université Paris Descartes-Sorbonne Paris Cité, Paris F-75993, France.
| | - Etienne Morel
- Institut Necker-Enfants Malades (INEM), INSERM U1151-CNRS UMR 8253, Paris F-75014, France.
- Université Paris Descartes-Sorbonne Paris Cité, Paris F-75993, France.
| | - Diana Molino
- Institut Necker-Enfants Malades (INEM), INSERM U1151-CNRS UMR 8253, Paris F-75014, France.
- Université Paris Descartes-Sorbonne Paris Cité, Paris F-75993, France.
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55
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Abstract
To survive, organisms require mechanisms that enable them to sense changes in the outside environment, introduce necessary responses, and resist unfavorable distortion. Consequently, through evolutionary adaptation, cells have become equipped with the apparatus required to monitor their fundamental intracellular processes and the mechanisms needed to try to offset malfunction without receiving any direct signals from the outside environment. It has been shown recently that eukaryotic cells are equipped with a special mechanism that monitors their fundamental cellular functions and that some pathogenic proteobacteria can override this monitoring mechanism to cause harm. The monitored cellular activities involved in the stressed intracellular response have been researched extensively in Caenorhabditis elegans, where discovery of an association between key mitochondrial activities and innate immune responses was named "cellular associated detoxification and defenses (cSADD)." This cellular surveillance pathway (cSADD) oversees core cellular activities such as mitochondrial respiration and protein transport into mitochondria, detects xenobiotics and invading pathogens, and activates the endocrine pathways controlling behavior, detoxification, and immunity. The cSADD pathway is probably associated with cellular responses to stress in human inflammatory diseases. In the critical care field, the pathogenesis of lethal inflammatory syndromes (e.g., respiratory distress syndromes and sepsis) involves the disturbance of mitochondrial respiration leading to cell death. Up-to-date knowledge about monitored cellular activities and cSADD, especially focusing on mitochondrial involvement, can probably help fill a knowledge gap regarding the pathogenesis of lethal inflammatory syndromes in the critical care field.
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56
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Nerlich A, Mieth M, Letsiou E, Fatykhova D, Zscheppang K, Imai-Matsushima A, Meyer TF, Paasch L, Mitchell TJ, Tönnies M, Bauer TT, Schneider P, Neudecker J, Rückert JC, Eggeling S, Schimek M, Witzenrath M, Suttorp N, Hippenstiel S, Hocke AC. Pneumolysin induced mitochondrial dysfunction leads to release of mitochondrial DNA. Sci Rep 2018; 8:182. [PMID: 29317705 PMCID: PMC5760655 DOI: 10.1038/s41598-017-18468-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 12/12/2017] [Indexed: 01/01/2023] Open
Abstract
Streptococcus pneumoniae (S.pn.) is the most common bacterial pathogen causing community acquired pneumonia. The pore-forming toxin pneumolysin (PLY) is the major virulence factor of S.pn. and supposed to affect alveolar epithelial cells thereby activating the immune system by liberation of danger-associated molecular patterns (DAMP). To test this hypothesis, we established a novel live-cell imaging based assay to analyse mitochondrial function and associated release of mitochondrial DNA (mtDNA) as DAMP in real-time. We first revealed that bacterially released PLY caused significant changes of the cellular ATP homeostasis and led to morphologic alterations of mitochondria in human alveolar epithelial cells in vitro and, by use of spectral live-tissue imaging, in human alveoli. This was accompanied by strong mitochondrial calcium influx and loss of mitochondrial membrane potential resulting in opening of the mitochondrial permeability transition pore and mtDNA release without activation of intrinsic apoptosis. Moreover, our data indicate cellular mtDNA liberation via microvesicles, which may contribute to S.pn. related pro-inflammatory immune activation in the human alveolar compartment.
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Affiliation(s)
- Andreas Nerlich
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Maren Mieth
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Eleftheria Letsiou
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Diana Fatykhova
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Katja Zscheppang
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Aki Imai-Matsushima
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Charitéplatz 1, 10117, Berlin, Germany
| | - Thomas F Meyer
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Charitéplatz 1, 10117, Berlin, Germany
| | - Lisa Paasch
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Timothy J Mitchell
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, B15-2TT, UK
| | - Mario Tönnies
- Department of Pneumology and Department of Thoracic Surgery, HELIOS Clinic Emil von Behring, Walterhöferstr 11, 14165, Berlin, Germany
| | - Torsten T Bauer
- Department of Pneumology and Department of Thoracic Surgery, HELIOS Clinic Emil von Behring, Walterhöferstr 11, 14165, Berlin, Germany
| | - Paul Schneider
- Department for General and Thoracic Surgery, DRK Clinics, Drontheimer Strasse 39-40, 13359, Berlin, Germany
| | - Jens Neudecker
- Department of General, Visceral, Vascular and Thoracic Surgery, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Jens C Rückert
- Department of General, Visceral, Vascular and Thoracic Surgery, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Stephan Eggeling
- Department of Thoracic Surgery, Vivantes Clinics Neukölln, Rudower Straße 48, 12351, Berlin, Germany
| | - Maria Schimek
- Department of Thoracic Surgery, Vivantes Clinics Neukölln, Rudower Straße 48, 12351, Berlin, Germany
| | - Martin Witzenrath
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Norbert Suttorp
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Stefan Hippenstiel
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Andreas C Hocke
- Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany.
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57
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Oeding SJ, Majstrowicz K, Hu XP, Schwarz V, Freitag A, Honnert U, Nikolaus P, Bähler M. Identification of Miro as a mitochondrial receptor for myosin XIX. J Cell Sci 2018; 131:jcs.219469. [DOI: 10.1242/jcs.219469] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 08/02/2018] [Indexed: 12/13/2022] Open
Abstract
Mitochondrial distribution in cells is critical for cellular function and proper inheritance during cell division. In mammalian cells, mitochondria are transported predominantly along microtubules by kinesin and dynein motors that bind indirectly via TRAK1/2 to outer mitochondrial membrane proteins Miro1/2. Here, using proximity labeling, we identified Miro1/2 as potential binding partners of myosin XIX (Myo19). Interaction studies show that Miro1 binds directly to a C-terminal fragment of the Myo19 tail region and that Miro recruits the Myo19 tail in vivo. This recruitment is regulated by the nucleotide-state of the N-terminal Rho-like GTPase domain of Miro. Notably, Myo19 protein stability in cells depends on its association with Miro. Downregulation of Miro or overexpression of the adapter proteins TRAK1 and TRAK2 caused a reduction in Myo19 protein levels. Finally, Myo19 regulates the subcellular distribution of mitochondria. Downregulation, as well as overexpression, of Myo19 induces perinuclear collapse of mitochondria, phenocopying the loss of kinesin KIF5, dynein or their mitochondrial receptor Miro. These results suggest that Miro coordinates microtubule- and actin-based mitochondrial movement.
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Affiliation(s)
- Stefanie J. Oeding
- Institute of Molecular Cell Biology, Westfalian Wilhelms University Münster, Germany
| | - Katarzyna Majstrowicz
- Institute of Molecular Cell Biology, Westfalian Wilhelms University Münster, Germany
| | - Xiao-Ping Hu
- Institute of Molecular Cell Biology, Westfalian Wilhelms University Münster, Germany
| | - Vera Schwarz
- Institute of Molecular Cell Biology, Westfalian Wilhelms University Münster, Germany
| | - Angelika Freitag
- Institute of Molecular Cell Biology, Westfalian Wilhelms University Münster, Germany
| | - Ulrike Honnert
- Institute of Molecular Cell Biology, Westfalian Wilhelms University Münster, Germany
| | - Petra Nikolaus
- Institute of Molecular Cell Biology, Westfalian Wilhelms University Münster, Germany
| | - Martin Bähler
- Institute of Molecular Cell Biology, Westfalian Wilhelms University Münster, Germany
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58
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Escoll P, Song OR, Viana F, Steiner B, Lagache T, Olivo-Marin JC, Impens F, Brodin P, Hilbi H, Buchrieser C. Legionella pneumophila Modulates Mitochondrial Dynamics to Trigger Metabolic Repurposing of Infected Macrophages. Cell Host Microbe 2017; 22:302-316.e7. [PMID: 28867389 DOI: 10.1016/j.chom.2017.07.020] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Revised: 06/14/2017] [Accepted: 07/28/2017] [Indexed: 12/12/2022]
Abstract
The intracellular bacteria Legionella pneumophila encodes a type IV secretion system (T4SS) that injects effector proteins into macrophages in order to establish and replicate within the Legionella-containing vacuole (LCV). Once generated, the LCV interacts with mitochondria through unclear mechanisms. We show that Legionella uses both T4SS-independent and T4SS-dependent mechanisms to respectively interact with mitochondria and induce mitochondrial fragmentation that ultimately alters mitochondrial metabolism. The T4SS effector MitF, a Ran GTPase activator, is required for fission of the mitochondrial network. These effects of MitF occur through accumulation of mitochondrial DNM1L, a GTPase critical for fission. Furthermore mitochondrial respiration is abruptly halted in a T4SS-dependent manner, while T4SS-independent upregulation of cellular glycolysis remains elevated. Collectively, these alterations in mitochondrial dynamics promote a Warburg-like phenotype in macrophages that favors bacterial replication. Hence the rewiring of cellular bioenergetics to create a replication permissive niche in host cells is a virulence strategy of L. pneumophila.
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Affiliation(s)
- Pedro Escoll
- Institut Pasteur, Biologie des Bactéries Intracellulaires, Paris 75724, France; CNRS UMR 3525, Paris 75724, France
| | - Ok-Ryul Song
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204-CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Flávia Viana
- Institut Pasteur, Biologie des Bactéries Intracellulaires, Paris 75724, France; CNRS UMR 3525, Paris 75724, France
| | - Bernhard Steiner
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Thibault Lagache
- Institut Pasteur, Unité d'Analyse d'Images Biologiques, CNRS UMR 3691, Paris, France
| | | | - Francis Impens
- VIB-UGent Center for Medical Biotechnology, Ghent University, 9000 Ghent, Belgium; VIB Proteomics Core, Ghent University, 9000 Ghent, Belgium; Department of Biochemistry, Ghent University, 9000 Ghent, Belgium
| | - Priscille Brodin
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204-CIIL-Center for Infection and Immunity of Lille, 59000 Lille, France
| | - Hubert Hilbi
- Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Carmen Buchrieser
- Institut Pasteur, Biologie des Bactéries Intracellulaires, Paris 75724, France; CNRS UMR 3525, Paris 75724, France.
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59
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Patel S, Rani A, Goyal A. Insights into the immune manipulation mechanisms of pollen allergens by protein domain profiling. Comput Biol Chem 2017; 70:31-39. [PMID: 28780227 DOI: 10.1016/j.compbiolchem.2017.07.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 04/13/2017] [Accepted: 07/26/2017] [Indexed: 11/25/2022]
Abstract
Plant pollens are airborne allergens, as their inhalation causes immune activation, leading to rhinitis, conjunctivitis, sinusitis and oral allergy syndrome. A myriad of pollen proteins belonging to profilin, expansin, polygalacturonase, glucan endoglucosidase, pectin esterase, and lipid transfer protein class have been identified. In the present in silico study, the protein domains of fifteen pollen sequences were extracted from the UniProt database and submitted to the interactive web tool SMART (Simple Modular Architecture Research Tool), for finding the protein domain profiles. Analysis of the data based on custom-made scripts revealed the conservation of pathogenic domains such as OmpH, PROF, PreSET, Bet_v_1, Cpl-7 and GAS2. Further, the retention of critical domains like CHASE2, Galanin, Dak2, DALR_1, HAMP, PWI, EFh, Excalibur, CT, PbH1, HELICc, and Kelch in pollen proteins, much like cockroach allergens and lethal viruses (such as HIV, HCV, Ebola, Dengue and Zika) was observed. Based on the shared motifs in proteins of taxonomicall-ydispersed organisms, it can be hypothesized that allergens and pathogens manipulate the human immune system in a similar manner. Allergens, being inanimate, cannot replicate in human body, and are neutralized by immune system. But, when the allergens are unremitting, the immune system becomes persistently hyper-sensitized, creating an inflammatory milieu. This study is expected to contribute to the understanding of pollen allergenicity and pathogenicity.
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Affiliation(s)
- Seema Patel
- Bioinformatics and Medical Informatics Research Center, San Diego State University, San Diego 92182, USA.
| | - Aruna Rani
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Arun Goyal
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
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60
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Qureshi MA, Haynes CM, Pellegrino MW. The mitochondrial unfolded protein response: Signaling from the powerhouse. J Biol Chem 2017; 292:13500-13506. [PMID: 28687630 DOI: 10.1074/jbc.r117.791061] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Mitochondria are multifaceted and indispensable organelles required for cell performance. Accordingly, dysfunction to mitochondria can result in cellular decline and possibly the onset of disease. Cells use a variety of means to recover mitochondria and restore homeostasis, including the activation of retrograde pathways such as the mitochondrial unfolded protein response (UPRmt). In this Minireview, we will discuss how cells adapt to mitochondrial stress through UPRmt regulation. Furthermore, we will explore the current repertoire of biological functions that are associated with this essential stress-response pathway.
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Affiliation(s)
- Mohammed A Qureshi
- From the Department of Biology, University of Texas Arlington, Arlington, Texas 76019 and
| | - Cole M Haynes
- the Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Mark W Pellegrino
- From the Department of Biology, University of Texas Arlington, Arlington, Texas 76019 and
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61
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Rolhion N, Cossart P. How the study of Listeria monocytogenes has led to new concepts in biology. Future Microbiol 2017; 12:621-638. [PMID: 28604108 DOI: 10.2217/fmb-2016-0221] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The opportunistic intracellular bacterial pathogen Listeria monocytogenes has in 30 years emerged as an exceptional bacterial model system in infection biology. Research on this bacterium has provided considerable insight into how pathogenic bacteria adapt to mammalian hosts, invade eukaryotic cells, move intracellularly, interfere with host cell functions and disseminate within tissues. It also contributed to unveil features of normal host cell pathways and unsuspected functions of previously known cellular proteins. This review provides an updated overview of our knowledge on this pathogen. In many examples, findings on L. monocytogenes provided the basis for new concepts in bacterial regulation, cell biology and infection processes.
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Affiliation(s)
- Nathalie Rolhion
- Département de Biologie Cellulaire et Infection, Unité des Interactions Bactéries-Cellules, Institut Pasteur, F-75015 Paris, France.,INSERM, U604, F-75015 Paris, France.,INRA, Unité sous-contrat 2020, F-75015 Paris, France
| | - Pascale Cossart
- Département de Biologie Cellulaire et Infection, Unité des Interactions Bactéries-Cellules, Institut Pasteur, F-75015 Paris, France.,INSERM, U604, F-75015 Paris, France.,INRA, Unité sous-contrat 2020, F-75015 Paris, France
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62
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Patel S. Pathogenicity-associated protein domains: The fiercely-conserved evolutionary signatures. GENE REPORTS 2017; 7:127-141. [PMID: 32363241 PMCID: PMC7185390 DOI: 10.1016/j.genrep.2017.04.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Revised: 03/29/2017] [Accepted: 04/07/2017] [Indexed: 12/15/2022]
Abstract
Proteins have highly conserved domains that determine their functionality. Out of the thousands of domains discovered so far across all living forms, some of the predominant clinically-relevant domains include IENR1, HNHc, HELICc, Pro-kuma_activ, Tryp_SPc, Lactamase_B, PbH1, ChtBD3, CBM49, acidPPc, G3P_acyltransf, RPOL8c, KbaA, HAMP, HisKA, Hr1, Dak2, APC2, Citrate_ly_lig, DALR, VKc, YARHG, WR1, PWI, ZnF_BED, TUDOR, MHC_II_beta, Integrin_B_tail, Excalibur, DISIN, Cadherin, ACTIN, PROF, Robl_LC7, MIT, Kelch, GAS2, B41, Cyclin_C, Connexin_CCC, OmpH, Bac_rhodopsin, AAA, Knot1, NH, Galanin, IB, Elicitin, ACTH, Cache_2, CHASE, AgrB, PRP, IGR, and Antimicrobial21. These domains are distributed in nucleases/helicases, proteases, esterases, lipases, glycosylase, GTPases, phosphatases, methyltransferases, acyltransferase, acetyltransferase, polymerase, kinase, ligase, synthetase, oxidoreductase, protease inhibitors, nucleic acid binding proteins, adhesion and immunity-related proteins, cytoskeletal component-manipulating proteins, lipid biosynthesis and metabolism proteins, membrane-associated proteins, hormone-like and signaling proteins, etc. These domains are ubiquitous stretches or folds of the proteins in pathogens and allergens. Pathogenesis alleviation efforts can benefit enormously if the characteristics of these domains are known. Hence, this review catalogs and discusses the role of such pivotal domains, suggesting hypotheses for better understanding of pathogenesis at molecular level. Proteins have highly conserved regions or domains across pathogens and allergens. Knowledge on these critical domains can facilitate our understanding of pathogenesis mechanisms. Such immune manipulation-related domains include IENR1, HNHc, HELICc, ACTIN, PROF, Robl_LC7, OmpH etc. These domains are presnt in enzyme, transcription regulators, adhesion proteins, and hormones. This review discusses and hypothesizes on these domains.
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Key Words
- CARDs, caspase activation and recruitment domains
- CBM, carbohydrate binding module
- CTD, C-terminal domain
- ChtBD, chitin-binding domain
- Diversification
- HNHc, homing endonucleases
- HTH, helix-turn-helix
- IENR1, intron-encoded endonuclease repeat
- Immune manipulation
- PAMPs, pathogen associated molecular patterns
- Pathogenesis
- Phylogenetic conservation
- Protein domains
- SMART, Simple Modular Architecture Research Tool
- Shuffling
- UDG, uracil DNA glycosylase
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Affiliation(s)
- Seema Patel
- Bioinformatics and Medical Informatics Research Center, San Diego State University, San Diego 92182, USA
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63
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Bankapalli LK, Mishra RC, Raychaudhuri S. VopE, a Vibrio cholerae Type III Effector, Attenuates the Activation of CWI-MAPK Pathway in Yeast Model System. Front Cell Infect Microbiol 2017; 7:82. [PMID: 28373966 PMCID: PMC5357651 DOI: 10.3389/fcimb.2017.00082] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 03/02/2017] [Indexed: 01/05/2023] Open
Abstract
VopE, a mitochondrial targeting T3SS effector protein of Vibrio cholerae, perturbs innate immunity by modulating mitochondrial dynamics. In the current study, ectopic expression of VopE was found to be toxic in a yeast model system and toxicity was further aggravated in the presence of various stressors. Interestingly, a VopE variant lacking predicted mitochondrial targeting sequence (MTS) also exhibited partial lethality in the yeast system. With the aid of yeast genetic tools and different stressors, we have demonstrated that VopE and its derivative VopEΔMTS modulate cell wall integrity (CWI-MAPK) signaling pathway and have identified several critical residues contributing to the lethality of VopE. Furthermore, co-expression of two effectors VopEΔMTS and VopX, interfering with the CWI-MAPK cellular pathway can partially suppress the VopX mediated yeast growth inhibition. Taken together, these results suggest that VopE alters signaling through the CWI-MAPK pathway, and demonstrates the usefulness of yeast model system to gain additional insights on the functionality of VopE.
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Affiliation(s)
- Leela K Bankapalli
- Molecular Biology and Microbial Physiology, Institute of Microbial Technology Chandigarh, India
| | - Rahul C Mishra
- Molecular Biology and Microbial Physiology, Institute of Microbial Technology Chandigarh, India
| | - Saumya Raychaudhuri
- Molecular Biology and Microbial Physiology, Institute of Microbial Technology Chandigarh, India
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Genetic variants of the MAVS, MITA and MFN2 genes are not associated with leprosy in Han Chinese from Southwest China. INFECTION GENETICS AND EVOLUTION 2016; 45:105-110. [DOI: 10.1016/j.meegid.2016.08.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 08/19/2016] [Accepted: 08/19/2016] [Indexed: 01/04/2023]
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65
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Sandhir R, Halder A, Sunkaria A. Mitochondria as a centrally positioned hub in the innate immune response. Biochim Biophys Acta Mol Basis Dis 2016; 1863:1090-1097. [PMID: 27794419 DOI: 10.1016/j.bbadis.2016.10.020] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 10/21/2016] [Accepted: 10/22/2016] [Indexed: 12/28/2022]
Abstract
Mitochondria are vital organelles involved in numerous cellular functions ranging from energy metabolism to cell survival. Emerging evidence suggests that mitochondria provide a platform for signaling pathways involved in innate immune response. Mitochondrial ROS (mtROS) production, mitochondrial DNA (mtDNA) release, mitochondrial antiviral signaling protein (MAVS) are key triggers in the activation of innate immune response following variety of stress signals that include infection, tissue damage and metabolic dysregulation. The process is mediated through pattern recognition receptors (PRRs) that consist of retinoic acid inducible gene like receptors (RLRs), c-type lectin receptors (CLRs), toll type receptors (TLRs) and nuclear oligomerization-domain like receptors (NLRs). These signals converge to form a multiprotein complex called inflammasome that leads to caspase-1 activation to promote processing of precursor cytokines (pro-IL1β and pro-IL-18) to active cytokines (IL-1β and IL-18). It appears that mitochondria induced inflammasome activation contributes to inflammatory process in many diverse disorders. Therefore, strategies aimed at modulating mitochondria mediated inflammasome activation might be beneficial in many pathophysiological conditions. This article is part of a Special Issue entitled: Oxidative Stress and Mitochondrial Quality in Diabetes/Obesity and Critical Illness Spectrum of Diseases - edited by P. Hemachandra Reddy.
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Affiliation(s)
- Rajat Sandhir
- Department of Biochemistry, Panjab University, Chandigarh, India.
| | - Avishek Halder
- Department of Biochemistry, Panjab University, Chandigarh, India
| | - Aditya Sunkaria
- Department of Biochemistry, Panjab University, Chandigarh, India
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66
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Fielden LF, Kang Y, Newton HJ, Stojanovski D. Targeting mitochondria: how intravacuolar bacterial pathogens manipulate mitochondria. Cell Tissue Res 2016; 367:141-154. [PMID: 27515462 DOI: 10.1007/s00441-016-2475-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Accepted: 07/07/2016] [Indexed: 02/07/2023]
Abstract
Manipulation of host cell function by bacterial pathogens is paramount for successful invasion and creation of a niche conducive to bacterial replication. Mitochondria play a role in many important cellular processes including energy production, cellular calcium homeostasis, lipid metabolism, haeme biosynthesis, immune signalling and apoptosis. The sophisticated integration of host cell processes by the mitochondrion have seen it emerge as a key target during bacterial infection of human host cells. This review highlights the targeting and interaction of this dynamic organelle by intravacuolar bacterial pathogens and the way that the modulation of mitochondrial function might contribute to pathogenesis.
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Affiliation(s)
- Laura F Fielden
- Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Yilin Kang
- Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Hayley J Newton
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Parkville, VIC, 3000, Australia.
| | - Diana Stojanovski
- Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, 3010, Australia.
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67
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Miller KA, Chaand M, Gregoire S, Yoshida T, Beck LA, Ivanov AI, Dziejman M. Characterization of V. cholerae T3SS-dependent cytotoxicity in cultured intestinal epithelial cells. Cell Microbiol 2016; 18:1857-1870. [PMID: 27302486 DOI: 10.1111/cmi.12629] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 06/01/2016] [Indexed: 12/22/2022]
Abstract
AM-19226 is a pathogenic, non-O1/non-O139 serogroup strain of Vibrio cholerae that uses a Type 3 Secretion System (T3SS) mediated mechanism to colonize host tissues and disrupt homeostasis, causing cholera. Co-culturing the Caco2-BBE human intestinal epithelial cell line with AM-19226 in the presence of bile results in rapid mammalian cell death that requires a functional T3SS. We examined the role of bile, sought to identify the mechanism, and evaluated the contributions of T3SS translocated effectors in in vitro cell death. Our results suggest that Caco2-BBE cytotoxicity does not proceed by apoptotic or necrotic mechanisms, but rather displays characteristics consistent with osmotic lysis. Cell death was preceded by disassembly of epithelial junctions and reorganization of the cortical membrane skeleton, although neither cell death nor cell-cell disruption required VopM or VopF, two effectors known to alter actin dynamics. Using deletion strains, we identified a subset of AM-19226 Vops that are required for host cell death, which were previously assigned roles in protein translocation and colonization, suggesting that they function other than to promote cytotoxicity. The collective results therefore suggest that cooperative Vop activities are required to achieve cytotoxicity in vitro, or alternatively, that translocon pores destabilize the membrane in a bile dependent manner.
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Affiliation(s)
- Kelly A Miller
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Mudit Chaand
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Stacy Gregoire
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Takeshi Yoshida
- Department of Dermatology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Lisa A Beck
- Department of Dermatology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Andrei I Ivanov
- Gastroenterology and Hepatology Division, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Michelle Dziejman
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
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68
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Devine MJ, Birsa N, Kittler JT. Miro sculpts mitochondrial dynamics in neuronal health and disease. Neurobiol Dis 2016; 90:27-34. [DOI: 10.1016/j.nbd.2015.12.008] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 12/17/2015] [Indexed: 01/18/2023] Open
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Regulation by ToxR-Like Proteins Converges on vttRB Expression To Control Type 3 Secretion System-Dependent Caco2-BBE Cytotoxicity in Vibrio cholerae. J Bacteriol 2016; 198:1675-1682. [PMID: 27021561 DOI: 10.1128/jb.00130-16] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 03/21/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Genes carried on the type 3 secretion system (T3SS) pathogenicity island of Vibrio cholerae non-O1/non-O139 serogroup strain AM-19226 must be precisely regulated in order for bacteria to cause disease. Previously reported results showed that both T3SS function and the presence of bile are required to cause Caco2-BBE cell cytotoxicity during coculture with strain AM-19226. We therefore investigated additional parameters affecting in vitro cell death, including bacterial load and the role of three transmembrane transcriptional regulatory proteins, VttRA, VttRB, and ToxR. VttRA and VttRB are encoded on the horizontally acquired T3SS genomic island, whereas ToxR is encoded on the ancestral chromosome. While strains carrying deletions in any one of the three transcriptional regulatory genes are unable to cause eukaryotic cell death, the results of complementation studies point to a hierarchy of regulatory control that converges on vttRB expression. The data suggest both that ToxR and VttRA act upstream of VttRB and that modifying the level of either vttRA or vttRB expression can strongly influence T3SS gene expression. We therefore propose a model whereby T3SS activity and, hence, in vitro cytotoxicity are ultimately regulated by vttRB expression. IMPORTANCE In contrast to O1 and O139 serogroup V. cholerae strains that cause cholera using two main virulence factors (toxin-coregulated pilus [TCP] and cholera toxin [CT]), O39 serogroup strain AM-19226 uses a type 3 secretion system as its principal virulence mechanism. Although the regulatory network governing TCP and CT expression is well understood, the factors influencing T3SS-associated virulence are not. Using an in vitro mammalian cell model to investigate the role of three ToxR-like transmembrane transcriptional activators in causing T3SS-dependent cytotoxicity, we found that expression levels and a hierarchical organization were important for promoting T3SS gene expression. Furthermore, our results suggest that horizontally acquired, ToxR-like proteins act in concert with the ancestral ToxR protein to orchestrate T3SS-mediated pathogenicity.
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70
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Colaço HG, Moita LF. Initiation of innate immune responses by surveillance of homeostasis perturbations. FEBS J 2016; 283:2448-57. [PMID: 27037950 DOI: 10.1111/febs.13730] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 03/20/2016] [Accepted: 04/01/2016] [Indexed: 01/01/2023]
Abstract
Pathogen recognition, signaling transduction pathways, and effector mechanisms are necessary steps of innate immune responses that play key roles in the early phase of defense and in the stimulation of the later specific response of adaptive immunity. Here, we argue that in addition to the direct recognition of conserved common structural and functional molecular signatures of microorganisms using pattern recognition receptors, hosts can mount an immune response following the sensing of disruption in homeostasis as proximal reporters for infections. Surveillance of disruption of core cellular activities leading to defense responses is a flexible strategy that requires few additional components and that can effectively detect relevant threats. It is likely to be evolutionarily very conserved and ancient because it is operational in organisms that lack pattern recognition triggered immunity. A homeostasis disruption model of immune response initiation and modulation has broad implications for pathophysiology and treatment of disease and might constitute an often overlooked but central component of a comprehensive conceptual framework for innate immunity.
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Affiliation(s)
- Henrique G Colaço
- Innate Immunity and Inflammation Laboratory, Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Luis F Moita
- Innate Immunity and Inflammation Laboratory, Instituto Gulbenkian de Ciência, Oeiras, Portugal
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71
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Abstract
During mitosis, cells undergo massive deformation and reorganization, impacting on all cellular structures. Mitochondria, in particular, are highly dynamic organelles, which constantly undergo events of fission, fusion and cytoskeleton-based transport. This plasticity ensures the proper distribution of the metabolism, and the proper inheritance of functional organelles. During cell cycle, mitochondria undergo dramatic changes in distribution. In this review, we focus on the dynamic events that target mitochondria during mitosis. We describe how the cell-cycle-dependent microtubule-associated protein centromeric protein F (Cenp-F) is recruited to mitochondria by the mitochondrial Rho GTPase (Miro) to promote mitochondrial transport and re-distribution following cell division.
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72
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Tang BL. MIRO GTPases in Mitochondrial Transport, Homeostasis and Pathology. Cells 2015; 5:cells5010001. [PMID: 26729171 PMCID: PMC4810086 DOI: 10.3390/cells5010001] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 12/22/2015] [Accepted: 12/24/2015] [Indexed: 01/08/2023] Open
Abstract
The evolutionarily-conserved mitochondrial Rho (MIRO) small GTPase is a Ras superfamily member with three unique features. It has two GTPase domains instead of the one found in other small GTPases, and it also has two EF hand calcium binding domains, which allow Ca2+-dependent modulation of its activity and functions. Importantly, it is specifically associated with the mitochondria and via a hydrophobic transmembrane domain, rather than a lipid-based anchor more commonly found in other small GTPases. At the mitochondria, MIRO regulates mitochondrial homeostasis and turnover. In metazoans, MIRO regulates mitochondrial transport and organization at cellular extensions, such as axons, and, in some cases, intercellular transport of the organelle through tunneling nanotubes. Recent findings have revealed a myriad of molecules that are associated with MIRO, particularly the kinesin adaptor Milton/TRAK, mitofusin, PINK1 and Parkin, as well as the endoplasmic reticulum-mitochondria encounter structure (ERMES) complex. The mechanistic aspects of the roles of MIRO and its interactors in mitochondrial homeostasis and transport are gradually being revealed. On the other hand, MIRO is also increasingly associated with neurodegenerative diseases that have roots in mitochondrial dysfunction. In this review, I discuss what is currently known about the cellular physiology and pathophysiology of MIRO functions.
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Affiliation(s)
- Bor Luen Tang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, MD7, 8 Medical Drive, Singapore 117597, Singapore.
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore.
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73
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Targeting of host organelles by pathogenic bacteria: a sophisticated subversion strategy. Nat Rev Microbiol 2015; 14:5-19. [PMID: 26594043 DOI: 10.1038/nrmicro.2015.1] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Many bacterial pathogens have evolved the ability to subvert and exploit host functions in order to enter and replicate in eukaryotic cells. For example, bacteria have developed specific mechanisms to target eukaryotic organelles such as the nucleus, the mitochondria, the endoplasmic reticulum and the Golgi apparatus. In this Review, we highlight the most recent advances in our understanding of the mechanisms that bacterial pathogens use to target these organelles. We also discuss how these strategies allow bacteria to manipulate host functions and to ultimately enable bacterial infection.
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74
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The Makes Caterpillars Floppy (MCF)-Like Domain of Vibrio vulnificus Induces Mitochondrion-Mediated Apoptosis. Infect Immun 2015; 83:4392-403. [PMID: 26351282 DOI: 10.1128/iai.00570-15] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Accepted: 08/26/2015] [Indexed: 12/17/2022] Open
Abstract
The multifunctional-autoprocessing repeats-in-toxin (MARTXVv) toxin of Vibrio vulnificus plays a significant role in the pathogenesis of this bacterium through delivery of up to five effector domains to the host cells. Previous studies have established that the MARTXVv toxin is linked to V. vulnificus dependent induction of apoptosis, but the region of the large multifunction protein essential for this activity was not previously identified. Recently, we showed that the Makes Caterpillar Floppy-like MARTX effector domain (MCFVv) is an autoproteolytic cysteine protease that induces rounding of various cell types. In this study, we demonstrate that cell rounding induced by MCFVv is coupled to reduced metabolic rate and inhibition of cellular proliferation. Moreover, delivery of MCFVv into host cells either as a fusion to the N-terminal fragment of anthrax toxin lethal factor or when naturally delivered as a V. vulnificus MARTX toxin led to loss of mitochondrial membrane potential, release of cytochrome c, activation of Bax and Bak, and processing of caspases and poly-(ADP-ribose) polymerase (PARP-γ). These studies specifically link the MCFVv effector domain to induction of the intrinsic apoptosis pathway by V. vulnificus.
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75
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Organelle targeting during bacterial infection: insights from Listeria. Trends Cell Biol 2015; 25:330-8. [DOI: 10.1016/j.tcb.2015.01.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 01/13/2015] [Accepted: 01/15/2015] [Indexed: 10/24/2022]
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76
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Type 3 Secretion System Island Encoded Proteins Required for Colonization by Non-O1/non-O139 Serogroup Vibrio cholerae. Infect Immun 2015; 83:2862-2869. [PMID: 25939511 DOI: 10.1128/iai.03020-14] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Vibrio cholerae is a genetically diverse species, and pathogenic strains can encode different virulence factors that mediate colonization and secretory diarrhea. Although the toxin co-regulated pilus (TCP) is the primary colonization factor in epidemic causing V. cholerae strains, other strains do not encode TCP and instead promote colonization via the activity of a type three secretion system (T3SS). Using the infant mouse model and T3SS-positive O39 serogroup strain AM-19226, we sought to determine which of 12 previously identified, T3SS translocated proteins (Vops) are important for host colonization. We constructed in frame deletions in each of the 12 loci in strain AM-19226, and identified five Vop deletion strains, including ΔVopM, which were severely attenuated for colonization. Interestingly, a subset of deletion strains was also incompetent for effector protein transport. Our collective data therefore suggest that several translocated proteins may also function as components of the structural apparatus or translocation machinery, and indicate that while VopM is critical for establishing an infection, the combined activities of other effectors may also contribute to the ability of T3SS-positive strains to colonize host epithelial cell surfaces.
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77
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Li Q, Yao L, Wei Y, Geng S, He C, Jiang H. Role of RHOT1 on migration and proliferation of pancreatic cancer. Am J Cancer Res 2015; 5:1460-1470. [PMID: 26101710 PMCID: PMC4473323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 03/12/2015] [Indexed: 06/04/2023] Open
Abstract
Pancreatic cancer (PC) is one of the most malignant tumors. Rho GTPases can affect several types of human cancers, including PC. In this study, we investigated the role of Ras homolog family member T1 (RHOT1), a new member of Rho GTPases in PC. IHC results showed that RHOT1 was expressed significantly higher in PC tissues than paracancerous tissues (P<0.01) and SMAD family member 4 (SMAD4) was expressed lower in PC tissues (P<0.01). RHOT1 was widely expressed in PC cell lines analyzed by reverse transcription PCR (RT-PCR), real-time quantitative PCR (RT-qPCR) and western blotting (WB). SiRNA-RHOT1 significantly suppressed the proliferation and migration of SW1990 cells. Moreover, SMAD4 was identified as an effector of RHOT1. Our findings suggest that RHOT1 can regulate cell migration and proliferation by suppressing the expression of SMAD4 in PC, which may provide a novel sight to explore the mechanism and therapeutic strategy for PC.
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Affiliation(s)
- Qingqing Li
- Department of Geriatrics, Shanghai East Hospital, Tongji University School of MedicineShanghai 200120, China
| | - Lei Yao
- Department of Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of MedicineShanghai 200120, China
| | - Youzhen Wei
- Department of Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of MedicineShanghai 200120, China
| | - Shasha Geng
- Department of Geriatrics, Shanghai East Hospital, Tongji University School of MedicineShanghai 200120, China
| | - Chengzhi He
- Department of Gastroenterology, Institute of Digestive Diseases, Tongji Hospital Affiliated to Tongji UniversityShanghai 200065, China
| | - Hua Jiang
- Department of Geriatrics, Shanghai East Hospital, Tongji University School of MedicineShanghai 200120, China
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78
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Lobet E, Letesson JJ, Arnould T. Mitochondria: a target for bacteria. Biochem Pharmacol 2015; 94:173-85. [PMID: 25707982 DOI: 10.1016/j.bcp.2015.02.007] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 02/12/2015] [Accepted: 02/12/2015] [Indexed: 01/12/2023]
Abstract
Eukaryotic cells developed strategies to detect and eradicate infections. The innate immune system, which is the first line of defence against invading pathogens, relies on the recognition of molecular patterns conserved among pathogens. Pathogen associated molecular pattern binding to pattern recognition receptor triggers the activation of several signalling pathways leading to the establishment of a pro-inflammatory state required to control the infection. In addition, pathogens evolved to subvert those responses (with passive and active strategies) allowing their entry and persistence in the host cells and tissues. Indeed, several bacteria actively manipulate immune system or interfere with the cell fate for their own benefit. One can imagine that bacterial effectors can potentially manipulate every single organelle in the cell. However, the multiple functions fulfilled by mitochondria especially their involvement in the regulation of innate immune response, make mitochondria a target of choice for bacterial pathogens as they are not only a key component of the central metabolism through ATP production and synthesis of various biomolecules but they also take part to cell signalling through ROS production and control of calcium homeostasis as well as the control of cell survival/programmed cell death. Furthermore, considering that mitochondria derived from an ancestral bacterial endosymbiosis, it is not surprising that a special connection does exist between this organelle and bacteria. In this review, we will discuss different mitochondrial functions that are affected during bacterial infection as well as different strategies developed by bacterial pathogens to subvert functions related to calcium homeostasis, maintenance of redox status and mitochondrial morphology.
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Affiliation(s)
- Elodie Lobet
- Laboratory of Biochemistry and Cellular Biology (URBC), NAmur Research Institute for LIfe Science (NARILIS), University of Namur, 61 Rue de Bruxelles, 5000 Namur, Belgium.
| | - Jean-Jacques Letesson
- Research Unit in Microorganisms Biology, University of Namur, 61 Rue de Bruxelles, 5000 Namur, Belgium.
| | - Thierry Arnould
- Laboratory of Biochemistry and Cellular Biology (URBC), NAmur Research Institute for LIfe Science (NARILIS), University of Namur, 61 Rue de Bruxelles, 5000 Namur, Belgium.
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79
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Holland RL, Blanke SR. Dynamic intervention: pathogen disarmament of mitochondrial-based immune surveillance. Cell Host Microbe 2014; 16:555-7. [PMID: 25525786 DOI: 10.1016/j.chom.2014.10.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
In this issue of Cell Host & Microbe, Suzuki et al. (2014) describe a Vibrio cholerae Type-III-secreted effector that targets mitochondrial dynamics to dampen host innate immune signaling. This suggests that mammalian hosts possess surveillance mechanisms to monitor pathogen-mediated alterations in the integrity of normal cellular processes and organelles.
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Affiliation(s)
- Robin L Holland
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
| | - Steven R Blanke
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA.
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