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Fabris F, Megighian A, Rossetto O, Simonato M, Schiavo G, Pirazzini M, Montecucco C. Local Tetanus Begins with a Neuromuscular Junction Paralysis around the Site of Tetanus Neurotoxin Release due to Cleavage of the Vesicle-Associated Membrane Protein. THE AMERICAN JOURNAL OF PATHOLOGY 2024; 194:1752-1763. [PMID: 38885925 DOI: 10.1016/j.ajpath.2024.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 05/14/2024] [Accepted: 05/23/2024] [Indexed: 06/20/2024]
Abstract
Local tetanus develops when limited amounts of tetanus neurotoxin (TeNT) are released by Clostridium tetani generated from spores inside a necrotic wound. Within days, a spastic paralysis restricted to the muscles of the affected anatomical area develops. This paralysis follows the retrograde transport of TeNT inside the axons of motoneurons and its uptake by inhibitory interneurons with cleavage of a vesicle-associated membrane protein required for neurotransmitter release. Consequently, incontrollable excitation of motoneurons causes contractures of innervated muscles and leads to local spastic paralysis. Here, the initial events occurring close to the site of TeNT release were investigated in a mouse model of local tetanus. A peripheral flaccid paralysis was found to occur, before or concurrent to the spastic paralysis. At variance from the confined TeNT proteolytic activity taking place within motor neuron terminals, central protein cleavage was detected within inhibitory interneurons controlling motor neuron efferents innervating muscle groups distant from the site of TeNT release. These results indicate peripheral activity of TeNT in tetanus and explains why the spastic paralysis observed in local tetanus, although confined to single limbs, generally affects multiple muscles. The initial TeNT neuroparalytic activity can be detected by measuring the compound muscle action potential, providing a very early diagnosis and therapy, thus preventing the ensuing life-threatening generalized tetanus.
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Affiliation(s)
- Federico Fabris
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Aram Megighian
- Department of Biomedical Sciences, University of Padua, Padua, Italy; Padua Neuroscience Center, University of Padua, Padua, Italy
| | - Ornella Rossetto
- Department of Biomedical Sciences, University of Padua, Padua, Italy; Center of Myology CIR-Myo, University of Padua, Padua, Italy; Institute of Neuroscience, National Research Council, Padua, Italy
| | - Morena Simonato
- Institute of Neuroscience, National Research Council, Padua, Italy
| | - Giampietro Schiavo
- Department of Neuromuscular Diseases and UCL Queen Square Motor Neuron Disease Centre, UCL Queen Square Institute of Neurology, London, United Kingdom; UK Dementia Research Institute, University College London, London, United Kingdom
| | - Marco Pirazzini
- Department of Biomedical Sciences, University of Padua, Padua, Italy; Center of Myology CIR-Myo, University of Padua, Padua, Italy.
| | - Cesare Montecucco
- Department of Biomedical Sciences, University of Padua, Padua, Italy; Institute of Neuroscience, National Research Council, Padua, Italy.
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2
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Van Dyck A, Masin L, Bergmans S, Schevenels G, Beckers A, Vanhollebeke B, Moons L. A new microfluidic model to study dendritic remodeling and mitochondrial dynamics during axonal regeneration of adult zebrafish retinal neurons. Front Mol Neurosci 2023; 16:1196504. [PMID: 37396787 PMCID: PMC10307971 DOI: 10.3389/fnmol.2023.1196504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 05/10/2023] [Indexed: 07/04/2023] Open
Abstract
Unlike mammals, adult zebrafish are able to fully regenerate axons and functionally recover from neuronal damage in the mature central nervous system (CNS). Decades of research have tried to identify the mechanisms behind their spontaneous regenerative capacity, but the exact underlying pathways and molecular drivers remain to be fully elucidated. By studying optic nerve injury-induced axonal regrowth of adult zebrafish retinal ganglion cells (RGCs), we previously reported transient dendritic shrinkage and changes in the distribution and morphology of mitochondria in the different neuronal compartments throughout the regenerative process. These data suggest that dendrite remodeling and temporary changes in mitochondrial dynamics contribute to effective axonal and dendritic repair upon optic nerve injury. To further elucidate these interactions, we here present a novel adult zebrafish microfluidic model in which we can demonstrate compartment-specific alterations in resource allocation in real-time at single neuron level. First, we developed a pioneering method that enables to isolate and culture adult zebrafish retinal neurons in a microfluidic setup. Notably, with this protocol, we report on a long-term adult primary neuronal culture with a high number of surviving and spontaneously outgrowing mature neurons, which was thus far only very limitedly described in literature. By performing time-lapse live cell imaging and kymographic analyses in this setup, we can explore changes in dendritic remodeling and mitochondrial motility during spontaneous axonal regeneration. This innovative model system will enable to discover how redirecting intraneuronal energy resources supports successful regeneration in the adult zebrafish CNS, and might facilitate the discovery of new therapeutic targets to promote neuronal repair in humans.
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Affiliation(s)
- Annelies Van Dyck
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Division, Department of Biology, Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Luca Masin
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Division, Department of Biology, Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Steven Bergmans
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Division, Department of Biology, Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Giel Schevenels
- Laboratory of Neurovascular Signaling, Department of Molecular Biology, ULB Neuroscience Institute, Université libre de Bruxelles, Gosselies, Belgium
| | - An Beckers
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Division, Department of Biology, Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Benoit Vanhollebeke
- Laboratory of Neurovascular Signaling, Department of Molecular Biology, ULB Neuroscience Institute, Université libre de Bruxelles, Gosselies, Belgium
| | - Lieve Moons
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Division, Department of Biology, Leuven Brain Institute, KU Leuven, Leuven, Belgium
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Sidibe DK, Kulkarni VV, Dong A, Herr JB, Vogel MC, Stempel MH, Maday S. Brain-derived neurotrophic factor stimulates the retrograde pathway for axonal autophagy. J Biol Chem 2022; 298:102673. [PMID: 36336077 PMCID: PMC9768381 DOI: 10.1016/j.jbc.2022.102673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 10/27/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022] Open
Abstract
Autophagy is a lysosomal degradation pathway important for neuronal development, function, and survival. How autophagy in axons is regulated by neurotrophins to impact neuronal viability and function is poorly understood. Here, we use live-cell imaging in primary neurons to investigate the regulation of axonal autophagy by the neurotrophin brain-derived neurotrophic factor (BDNF) and elucidate whether autophagosomes carry BDNF-mediated signaling information. We find that BDNF induces autophagic flux in primary neurons by stimulating the retrograde pathway for autophagy in axons. We observed an increase in autophagosome density and retrograde flux in axons, and a corresponding increase in autophagosome density in the soma. However, we find little evidence of autophagosomes comigrating with BDNF. In contrast, BDNF effectively engages its cognate receptor TrkB to undergo retrograde transport in the axon. These compartments, however, are distinct from LC3-positive autophagic organelles in the axon. Together, we find that BDNF stimulates autophagy in the axon, but retrograde autophagosomes do not appear to carry BDNF cargo. Thus, autophagosomes likely do not play a major role in relaying neurotrophic signaling information across the axon in the form of active BDNF/TrkB complexes. Rather, BDNF likely stimulates autophagy as a consequence of BDNF-induced processes that require canonical roles for autophagy in degradation.
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Affiliation(s)
| | | | | | | | | | | | - Sandra Maday
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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4
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Cai S, Kumar R, Singh BR. Clostridial Neurotoxins: Structure, Function and Implications to Other Bacterial Toxins. Microorganisms 2021; 9:2206. [PMID: 34835332 PMCID: PMC8618262 DOI: 10.3390/microorganisms9112206] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/19/2021] [Accepted: 10/19/2021] [Indexed: 01/20/2023] Open
Abstract
Gram-positive bacteria are ancient organisms. Many bacteria, including Gram-positive bacteria, produce toxins to manipulate the host, leading to various diseases. While the targets of Gram-positive bacterial toxins are diverse, many of those toxins use a similar mechanism to invade host cells and exert their functions. Clostridial neurotoxins produced by Clostridial tetani and Clostridial botulinum provide a classical example to illustrate the structure-function relationship of bacterial toxins. Here, we critically review the recent progress of the structure-function relationship of clostridial neurotoxins, including the diversity of the clostridial neurotoxins, the mode of actions, and the flexible structures required for the activation of toxins. The mechanism clostridial neurotoxins use for triggering their activity is shared with many other Gram-positive bacterial toxins, especially molten globule-type structures. This review also summarizes the implications of the molten globule-type flexible structures to other Gram-positive bacterial toxins. Understanding these highly dynamic flexible structures in solution and their role in the function of bacterial toxins not only fills in the missing link of the high-resolution structures from X-ray crystallography but also provides vital information for better designing antidotes against those toxins.
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Affiliation(s)
- Shuowei Cai
- Department of Chemistry and Biochemistry, University of Massachusetts Dartmouth, Dartmouth, MA 02747, USA
| | - Raj Kumar
- Botulinum Research Center, Institute of Advanced Sciences, Dartmouth, MA 02747, USA; (R.K.); (B.R.S.)
| | - Bal Ram Singh
- Botulinum Research Center, Institute of Advanced Sciences, Dartmouth, MA 02747, USA; (R.K.); (B.R.S.)
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Roesl C, Evans ER, Dissanayake KN, Boczonadi V, Jones RA, Jordan GR, Ledahawsky L, Allen GCC, Scott M, Thomson A, Wishart TM, Hughes DI, Mead RJ, Shone CC, Slater CR, Gillingwater TH, Skehel PA, Ribchester RR. Confocal Endomicroscopy of Neuromuscular Junctions Stained with Physiologically Inert Protein Fragments of Tetanus Toxin. Biomolecules 2021; 11:1499. [PMID: 34680132 PMCID: PMC8534034 DOI: 10.3390/biom11101499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 10/07/2021] [Accepted: 10/08/2021] [Indexed: 01/09/2023] Open
Abstract
Live imaging of neuromuscular junctions (NMJs) in situ has been constrained by the suitability of ligands for inert vital staining of motor nerve terminals. Here, we constructed several truncated derivatives of the tetanus toxin C-fragment (TetC) fused with Emerald Fluorescent Protein (emGFP). Four constructs, namely full length emGFP-TetC (emGFP-865:TetC) or truncations comprising amino acids 1066-1315 (emGFP-1066:TetC), 1093-1315 (emGFP-1093:TetC) and 1109-1315 (emGFP-1109:TetC), produced selective, high-contrast staining of motor nerve terminals in rodent or human muscle explants. Isometric tension and intracellular recordings of endplate potentials from mouse muscles indicated that neither full-length nor truncated emGFP-TetC constructs significantly impaired NMJ function or transmission. Motor nerve terminals stained with emGFP-TetC constructs were readily visualised in situ or in isolated preparations using fibre-optic confocal endomicroscopy (CEM). emGFP-TetC derivatives and CEM also visualised regenerated NMJs. Dual-waveband CEM imaging of preparations co-stained with fluorescent emGFP-TetC constructs and Alexa647-α-bungarotoxin resolved innervated from denervated NMJs in axotomized WldS mouse muscle and degenerating NMJs in transgenic SOD1G93A mouse muscle. Our findings highlight the region of the TetC fragment required for selective binding and visualisation of motor nerve terminals and show that fluorescent derivatives of TetC are suitable for in situ morphological and physiological characterisation of healthy, injured and diseased NMJs.
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Affiliation(s)
- Cornelia Roesl
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Elizabeth R. Evans
- Public Health England, National Infection Service, Porton Down, Salisbury SP4 0JG, UK; (E.R.E.); (C.C.S.)
| | - Kosala N. Dissanayake
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Veronika Boczonadi
- Applied Neuromuscular Junction Facility, Bio-Imaging Unit, Biosciences Institute, University of Newcastle-upon-Tyne, Framlington Place, Newcastle-upon-Tyne NE2 4HH, UK; (V.B.); (C.R.S.)
| | - Ross A. Jones
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Graeme R. Jordan
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Leire Ledahawsky
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Guy C. C. Allen
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Molly Scott
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Alanna Thomson
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Thomas M. Wishart
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, College of Medicine and Veterinary Medicine, University of Edinburgh, Easter Bush, Edinburgh EH25 9RG, UK;
| | - David I. Hughes
- Spinal Cord Research Group, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow G12 8QQ, UK;
| | - Richard J. Mead
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Glossop Road, Sheffield S10 2HQ, UK;
| | - Clifford C. Shone
- Public Health England, National Infection Service, Porton Down, Salisbury SP4 0JG, UK; (E.R.E.); (C.C.S.)
| | - Clarke R. Slater
- Applied Neuromuscular Junction Facility, Bio-Imaging Unit, Biosciences Institute, University of Newcastle-upon-Tyne, Framlington Place, Newcastle-upon-Tyne NE2 4HH, UK; (V.B.); (C.R.S.)
| | - Thomas H. Gillingwater
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Paul A. Skehel
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
| | - Richard R. Ribchester
- Centre for Discovery Brain Sciences and the Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK; (C.R.); (K.N.D.); (R.A.J.); (G.R.J.); (L.L.); (G.C.C.A.); (M.S.); (A.T.); (T.H.G.)
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6
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Melland H, Carr EM, Gordon SL. Disorders of synaptic vesicle fusion machinery. J Neurochem 2020; 157:130-164. [PMID: 32916768 DOI: 10.1111/jnc.15181] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/20/2020] [Accepted: 08/26/2020] [Indexed: 12/11/2022]
Abstract
The revolution in genetic technology has ushered in a new age for our understanding of the underlying causes of neurodevelopmental, neuromuscular and neurodegenerative disorders, revealing that the presynaptic machinery governing synaptic vesicle fusion is compromised in many of these neurological disorders. This builds upon decades of research showing that disturbance to neurotransmitter release via toxins can cause acute neurological dysfunction. In this review, we focus on disorders of synaptic vesicle fusion caused either by toxic insult to the presynapse or alterations to genes encoding the key proteins that control and regulate fusion: the SNARE proteins (synaptobrevin, syntaxin-1 and SNAP-25), Munc18, Munc13, synaptotagmin, complexin, CSPα, α-synuclein, PRRT2 and tomosyn. We discuss the roles of these proteins and the cellular and molecular mechanisms underpinning neurological deficits in these disorders.
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Affiliation(s)
- Holly Melland
- The Florey Institute of Neuroscience and Mental Health, Melbourne Dementia Research Centre, The University of Melbourne, Melbourne, Vic., Australia
| | - Elysa M Carr
- The Florey Institute of Neuroscience and Mental Health, Melbourne Dementia Research Centre, The University of Melbourne, Melbourne, Vic., Australia
| | - Sarah L Gordon
- The Florey Institute of Neuroscience and Mental Health, Melbourne Dementia Research Centre, The University of Melbourne, Melbourne, Vic., Australia
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Tosolini AP, Sleigh JN. Intramuscular Delivery of Gene Therapy for Targeting the Nervous System. Front Mol Neurosci 2020; 13:129. [PMID: 32765219 PMCID: PMC7379875 DOI: 10.3389/fnmol.2020.00129] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 06/26/2020] [Indexed: 12/11/2022] Open
Abstract
Virus-mediated gene therapy has the potential to deliver exogenous genetic material into specific cell types to promote survival and counteract disease. This is particularly enticing for neuronal conditions, as the nervous system is renowned for its intransigence to therapeutic targeting. Administration of gene therapy viruses into skeletal muscle, where distal terminals of motor and sensory neurons reside, has been shown to result in extensive transduction of cells within the spinal cord, brainstem, and sensory ganglia. This route is minimally invasive and therefore clinically relevant for gene therapy targeting to peripheral nerve soma. For successful transgene expression, viruses administered into muscle must undergo a series of processes, including host cell interaction and internalization, intracellular sorting, long-range retrograde axonal transport, endosomal liberation, and nuclear import. In this review article, we outline key characteristics of major gene therapy viruses—adenovirus, adeno-associated virus (AAV), and lentivirus—and summarize the mechanisms regulating important steps in the virus journey from binding at peripheral nerve terminals to nuclear delivery. Additionally, we describe how neuropathology can negatively influence these pathways, and conclude by discussing opportunities to optimize the intramuscular administration route to maximize gene delivery and thus therapeutic potential.
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Affiliation(s)
- Andrew P Tosolini
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - James N Sleigh
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom.,UK Dementia Research Institute, University College London, London, United Kingdom
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Abstract
Tetanus is a neurologic disease of humans and animals characterized by spastic paralysis. Tetanus is caused by tetanus toxin (TeNT) produced by Clostridium tetani, an environmental soilborne, gram-positive, sporulating bacterium. The disease most often results from wound contamination by soil containing C. tetani spores. Horses, sheep, and humans are highly sensitive to TeNT, whereas cattle, dogs, and cats are more resistant. The diagnosis of tetanus is mainly based on the characteristic clinical signs. Identification of C. tetani at the wound site is often difficult.
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Aravamudhan P, Raghunathan K, Konopka-Anstadt J, Pathak A, Sutherland DM, Carter BD, Dermody TS. Reovirus uses macropinocytosis-mediated entry and fast axonal transport to infect neurons. PLoS Pathog 2020; 16:e1008380. [PMID: 32109948 PMCID: PMC7065821 DOI: 10.1371/journal.ppat.1008380] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 03/11/2020] [Accepted: 02/04/2020] [Indexed: 12/12/2022] Open
Abstract
Several barriers protect the central nervous system (CNS) from pathogen invasion. Yet viral infections of the CNS are common and often debilitating. Understanding how neurotropic viruses co-opt host machinery to overcome challenges to neuronal entry and transmission is important to combat these infections. Neurotropic reovirus disseminates through neural routes and invades the CNS to cause lethal encephalitis in newborn animals. To define mechanisms of reovirus neuronal entry and directional transport, we used primary neuron cultures, which reproduce in vivo infection patterns displayed by different reovirus serotypes. Treatment of neurons with small-molecule inhibitors of different endocytic uptake pathways allowed us to discover that the cellular machinery mediating macropinocytosis is required for reovirus neuronal entry. This mechanism of reovirus entry differs from clathrin-mediated endocytosis, which is used by reovirus to invade non-neuronal cells. Analysis of reovirus transport and release from isolated soma or axonal termini of neurons cultivated in microfluidic devices indicates that reovirus is capable of retrograde but only limited anterograde neuronal transmission. The dynamics of retrograde reovirus movement are consistent with fast axonal transport coordinated by dynein along microtubules. Further analysis of viral transport revealed that multiple virions are transported together in axons within non-acidified vesicles. Reovirus-containing vesicles acidify after reaching the soma, where disassembly of virions and release of the viral core into the cytoplasm initiates replication. These results define mechanisms of reovirus neuronal entry and transport and establish a foundation to identify common host factors used by neuroinvasive viruses. Furthermore, our findings emphasize consideration of cell type-specific entry mechanisms in the tailored design of neurotropic viruses as tracers, oncolytic agents, and delivery vectors. Viral infections of the central nervous system (CNS) cause a significant health burden globally and compel a better mechanistic understanding of neural invasion by viruses to develop effective interventions. Neurotropic reovirus disseminates through neural routes to infect the CNS and serves as a tractable model to study neural invasion by viruses. Despite knowledge of reovirus neurotropism for decades, mechanisms mediating reovirus neuronal infection remain undefined. We used primary neurons cultured in microfluidic devices to study entry and directional transport of reovirus. We discovered that reovirus uses macropinocytosis for neuronal entry as opposed to the use of a clathrin-mediated pathway in non-neuronal cells. We are unaware of another virus using macropinocytosis to enter neurons. Following internalization, reovirus spreads in the retrograde direction using dynein-mediated fast axonal transport but exhibits limited anterograde spread. We further demonstrate that reovirus disassembly and replication occur in the neuronal soma subsequent to axonal transport. Remarkably, these entry and transport mechanisms mirror those used by misfolded proteins implicated in neurodegenerative diseases. Our findings establish the mechanics of reovirus neuronal uptake and spread and provide clues about therapeutic targets to limit neuropathology inflicted by pathogens and misfolded proteins.
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Affiliation(s)
- Pavithra Aravamudhan
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Center for Microbial Pathogenesis, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Krishnan Raghunathan
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Center for Microbial Pathogenesis, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Jennifer Konopka-Anstadt
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Amrita Pathak
- Department of Biochemistry and Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Danica M. Sutherland
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Center for Microbial Pathogenesis, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Bruce D. Carter
- Department of Biochemistry and Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Terence S. Dermody
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Center for Microbial Pathogenesis, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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10
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Surana S, Villarroel‐Campos D, Lazo OM, Moretto E, Tosolini AP, Rhymes ER, Richter S, Sleigh JN, Schiavo G. The evolution of the axonal transport toolkit. Traffic 2019; 21:13-33. [DOI: 10.1111/tra.12710] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 10/16/2019] [Accepted: 10/17/2019] [Indexed: 12/11/2022]
Affiliation(s)
- Sunaina Surana
- Department of Neuromuscular Diseases, UCL Queen Square Institute of NeurologyUniversity College London London UK
| | - David Villarroel‐Campos
- Department of Neuromuscular Diseases, UCL Queen Square Institute of NeurologyUniversity College London London UK
| | - Oscar M. Lazo
- Department of Neuromuscular Diseases, UCL Queen Square Institute of NeurologyUniversity College London London UK
- UK Dementia Research InstituteUniversity College London London UK
| | - Edoardo Moretto
- UK Dementia Research InstituteUniversity College London London UK
| | - Andrew P. Tosolini
- Department of Neuromuscular Diseases, UCL Queen Square Institute of NeurologyUniversity College London London UK
| | - Elena R. Rhymes
- Department of Neuromuscular Diseases, UCL Queen Square Institute of NeurologyUniversity College London London UK
| | - Sandy Richter
- Department of Neuromuscular Diseases, UCL Queen Square Institute of NeurologyUniversity College London London UK
| | - James N. Sleigh
- Department of Neuromuscular Diseases, UCL Queen Square Institute of NeurologyUniversity College London London UK
- UK Dementia Research InstituteUniversity College London London UK
| | - Giampietro Schiavo
- Department of Neuromuscular Diseases, UCL Queen Square Institute of NeurologyUniversity College London London UK
- UK Dementia Research InstituteUniversity College London London UK
- Discoveries Centre for Regenerative and Precision MedicineUniversity College London London UK
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Villarroel-Campos D, Schiavo G, Lazo OM. The many disguises of the signalling endosome. FEBS Lett 2018; 592:3615-3632. [PMID: 30176054 PMCID: PMC6282995 DOI: 10.1002/1873-3468.13235] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 08/29/2018] [Indexed: 01/09/2023]
Abstract
Neurons are highly complex and polarised cells that must overcome a series of logistic challenges to maintain homeostasis across their morphological domains. A very clear example is the propagation of neurotrophic signalling from distal axons, where target-released neurotrophins bind to their receptors and initiate signalling, towards the cell body, where nuclear and cytosolic responses are integrated. The mechanisms of propagation of neurotrophic signalling have been extensively studied and, eventually, the model of a 'signalling endosome', transporting activated receptors and associated complexes, has emerged. Nevertheless, the exact nature of this organelle remains elusive. In this Review, we examine the evidence for the retrograde transport of neurotrophins and their receptors in endosomes, outline some of their diverse physiological and pathological roles, and discuss the main interactors, morphological features and trafficking destinations of a highly flexible endosomal signalling organelle with multiple molecular signatures.
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Affiliation(s)
- David Villarroel-Campos
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, UK
| | - Giampietro Schiavo
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, UK.,UK Dementia Research Institute at UCL, London, UK.,Discoveries Centre for Regenerative and Precision Medicine, University College London Campus, UK
| | - Oscar Marcelo Lazo
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, UK
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12
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Surana S, Tosolini AP, Meyer IF, Fellows AD, Novoselov SS, Schiavo G. The travel diaries of tetanus and botulinum neurotoxins. Toxicon 2018; 147:58-67. [DOI: 10.1016/j.toxicon.2017.10.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 10/09/2017] [Accepted: 10/11/2017] [Indexed: 10/18/2022]
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13
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Masuyer G, Conrad J, Stenmark P. The structure of the tetanus toxin reveals pH-mediated domain dynamics. EMBO Rep 2017; 18:1306-1317. [PMID: 28645943 PMCID: PMC5538627 DOI: 10.15252/embr.201744198] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 05/16/2017] [Accepted: 05/23/2017] [Indexed: 11/09/2022] Open
Abstract
The tetanus neurotoxin (TeNT) is a highly potent toxin produced by Clostridium tetani that inhibits neurotransmission of inhibitory interneurons, causing spastic paralysis in the tetanus disease. TeNT differs from the other clostridial neurotoxins by its unique ability to target the central nervous system by retrograde axonal transport. The crystal structure of the tetanus toxin reveals a "closed" domain arrangement stabilised by two disulphide bridges, and the molecular details of the toxin's interaction with its polysaccharide receptor. An integrative analysis combining X-ray crystallography, solution scattering and single particle electron cryo-microscopy reveals pH-mediated domain rearrangements that may give TeNT the ability to adapt to the multiple environments encountered during intoxication, and facilitate binding to distinct receptors.
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Affiliation(s)
- Geoffrey Masuyer
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Julian Conrad
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
- Science for Life Laboratory, Stockholm University, Solna, Sweden
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
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14
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Connan C, Voillequin M, Chavez CV, Mazuet C, Leveque C, Vitry S, Vandewalle A, Popoff MR. Botulinum neurotoxin type B uses a distinct entry pathway mediated by CDC42 into intestinal cells versus neuronal cells. Cell Microbiol 2017; 19. [PMID: 28296078 DOI: 10.1111/cmi.12738] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/07/2017] [Accepted: 03/08/2017] [Indexed: 12/15/2022]
Abstract
Botulinum neurotoxins (BoNTs) are responsible for severe flaccid paralysis by inhibiting the release of acetylcholine at the neuromuscular junctions. BoNT type B (BoNT/B) most often induces mild forms of botulism with predominant dysautonomic symptoms. In food borne botulism and botulism by intestinal colonisation such as infant botulism, which are the most frequent naturally acquired forms of botulism, the digestive tract is the main entry route of BoNTs into the organism. We previously showed that BoNT/B translocates through mouse intestinal barrier by an endocytosis-dependent mechanism and subsequently targets neuronal cells, mainly cholinergic neurons, in the intestinal mucosa and musculosa. Here, we investigated the entry pathway of BoNT/B using fluorescent C-terminal domain of the heavy chain (HcB), which is involved in the binding to specific receptor(s) and entry process into target cells. While the combination of gangliosides GD1a /GD1b /GT1b and synaptotagmin I and to a greater extent synaptotagmin II constitutes the functional HcB receptor on NG108-15 neuronal cells, HcB only uses the gangliosides GD1a /GD1b /GT1b to efficiently bind to m-ICcl2 intestinal cells. HcB enters both cell types by a dynamin-dependent endocytosis, which is efficiently prevented by Dynasore, a dynamin inhibitor, and reaches a common early endosomal compartment labeled by early endosome antigen (EEA1). In contrast to neuronal cells, HcB uses a Cdc42-dependent pathway to enter intestinal cells. Then, HcB is transported to late endosomes in neuronal cells, whereas it exploits a nonacidified pathway from apical to basal lateral side of m-ICcl2 cells supporting a transcytotic route in epithelial intestinal cells.
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Affiliation(s)
- Chloé Connan
- Bactéries anaérobies et Toxines, Institut Pasteur, Paris, France
| | - Marie Voillequin
- Bactéries anaérobies et Toxines, Institut Pasteur, Paris, France
| | | | | | - Christian Leveque
- INSERM, UMR_S 1072 (UNIS), Faculté de Médecine -Secteur Nord, Aix Marseille Université, Marseille, France
| | - Sandrine Vitry
- Neuro-Immunologie Virale, Institut Pasteur, Paris, France
| | | | - Michel R Popoff
- Bactéries anaérobies et Toxines, Institut Pasteur, Paris, France
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15
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Connan C, Popoff MR. Uptake of Clostridial Neurotoxins into Cells and Dissemination. Curr Top Microbiol Immunol 2017; 406:39-78. [PMID: 28879524 DOI: 10.1007/82_2017_50] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Clostridial neurotoxins, botulinum neurotoxins (BoNT) and tetanus neurotoxin (TeNT), are potent toxins, which are responsible for severe neurological diseases in man and animals. BoNTs induce a flaccid paralysis (botulism) by inhibiting acetylcholine release at the neuromuscular junctions, whereas TeNT causes a spastic paralysis (tetanus) by blocking the neurotransmitter release (glycine, GABA) in inhibitory interneurons within the central nervous system. Clostridial neurotoxins recognize specific receptor(s) on the target neuronal cells and enter via a receptor-mediated endocytosis. They transit through an acidic compartment which allows the translocation of the catalytic chain into the cytosol, a prerequisite step for the intracellular activity of the neurotoxins. TeNT migrates to the central nervous system by using a motor neuron as transport cell. TeNT enters a neutral pH compartment and undergoes a retrograde axonal transport to the spinal cord or brain, where the whole undissociated toxin is delivered and interacts with target neurons. Botulism most often results from ingestion of food contaminated with BoNT. Thus, BoNT passes through the intestinal epithelial barrier mainly via a transcytotic mechanism and then diffuses or is transported to the neuromuscular junctions by the lymph or blood circulation. Indeed, clostridial neurotoxins are specific neurotoxins which transit through a transport cell to gain access to the target neuron, and use distinct trafficking pathways in both cell types.
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Affiliation(s)
- Chloé Connan
- Unité Des Bactéries Anaérobies et Toxines, Institut Pasteur, 25 Rue Du Dr Roux, 75724, Paris Cedex 15, France
| | - Michel R Popoff
- Unité Des Bactéries Anaérobies et Toxines, Institut Pasteur, 25 Rue Du Dr Roux, 75724, Paris Cedex 15, France.
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16
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Charlier CM, Debaisieux S, Foret C, Thouard A, Schiavo G, Gonzalez-Dunia D, Malnou CE. Neuronal retrograde transport of Borna disease virus occurs in signalling endosomes. J Gen Virol 2016; 97:3215-3224. [DOI: 10.1099/jgv.0.000652] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Affiliation(s)
- Caroline M. Charlier
- Centre de Physiopathologie de Toulouse Purpan, INSERM UMR 1043, CNRS UMR 5282, Université Toulouse III Paul Sabatier, Toulouse, France
| | - Solène Debaisieux
- Molecular Neuropathobiology Laboratory, Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, University College London, London, UK
| | - Charlotte Foret
- Centre de Physiopathologie de Toulouse Purpan, INSERM UMR 1043, CNRS UMR 5282, Université Toulouse III Paul Sabatier, Toulouse, France
| | - Anne Thouard
- Centre de Physiopathologie de Toulouse Purpan, INSERM UMR 1043, CNRS UMR 5282, Université Toulouse III Paul Sabatier, Toulouse, France
| | - Giampietro Schiavo
- Molecular Neuropathobiology Laboratory, Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, University College London, London, UK
| | - Daniel Gonzalez-Dunia
- Centre de Physiopathologie de Toulouse Purpan, INSERM UMR 1043, CNRS UMR 5282, Université Toulouse III Paul Sabatier, Toulouse, France
| | - Cécile E. Malnou
- Centre de Physiopathologie de Toulouse Purpan, INSERM UMR 1043, CNRS UMR 5282, Université Toulouse III Paul Sabatier, Toulouse, France
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17
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Ovsepian SV, O'Leary VB, Ntziachristos V, Dolly JO. Circumventing Brain Barriers: Nanovehicles for Retroaxonal Therapeutic Delivery. Trends Mol Med 2016; 22:983-993. [PMID: 27720365 DOI: 10.1016/j.molmed.2016.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 09/09/2016] [Accepted: 09/12/2016] [Indexed: 02/06/2023]
Abstract
In addition to safeguarding the central nervous system (CNS) from the vast majority of pathogens and toxins, transvascular barriers impose immense challenges to the delivery of beneficial cargo. A few toxins and neurotropic viruses capable of penetrating the brain have proved to be potentially valuable for neuron targeting and enhanced transfer of restorative medicine and therapeutic genes. Here we review molecular concepts and implications of the highly neurotropic tetanus toxin (TeTx) and botulinum neurotoxins (BoNTs) and their ability to infiltrate and migrate throughout neurons. We discuss recent applications of their detoxified variants as versatile nanovehicles for retroaxonal delivery of therapeutics to motor neurons and synapses. Continued advances in research on these remarkable agents in preclinical trials might facilitate their future use for medical benefit.
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Affiliation(s)
- Saak V Ovsepian
- Institute for Biological and Medical Imaging, Helmholtz Zentrum Munich, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany; Munich School of Bioengineering, Technical University Munich, 81675 Munich, Germany; International Centre for Neurotherapeutics, Dublin City University, Dublin 9, Ireland.
| | - Valerie B O'Leary
- Institute of Radiation Biology, Helmholtz Zentrum Munich, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
| | - Vasilis Ntziachristos
- Institute for Biological and Medical Imaging, Helmholtz Zentrum Munich, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany; Munich School of Bioengineering, Technical University Munich, 81675 Munich, Germany
| | - J Oliver Dolly
- International Centre for Neurotherapeutics, Dublin City University, Dublin 9, Ireland
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18
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Piccinotti S, Whelan SPJ. Rabies Internalizes into Primary Peripheral Neurons via Clathrin Coated Pits and Requires Fusion at the Cell Body. PLoS Pathog 2016; 12:e1005753. [PMID: 27463226 PMCID: PMC4963122 DOI: 10.1371/journal.ppat.1005753] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 06/17/2016] [Indexed: 12/21/2022] Open
Abstract
The single glycoprotein (G) of rabies virus (RABV) dictates all viral entry steps from receptor engagement to membrane fusion. To study the uptake of RABV into primary neuronal cells in culture, we generated a recombinant vesicular stomatitis virus in which the G protein was replaced with that of the neurotropic RABV CVS-11 strain (rVSV CVS G). Using microfluidic compartmentalized culture, we examined the uptake of single virions into the termini of primary neurons of the dorsal root ganglion and ventral spinal cord. By pharmacologically disrupting endocytosis at the distal neurites, we demonstrate that rVSV CVS G uptake and infection are dependent on dynamin. Imaging of single virion uptake with fluorescent endocytic markers further identifies endocytosis via clathrin-coated pits as the predominant internalization mechanism. Transmission electron micrographs also reveal the presence of viral particles in vesicular structures consistent with incompletely coated clathrin pits. This work extends our previous findings of clathrin-mediated uptake of RABV into epithelial cells to two neuronal subtypes involved in rabies infection in vivo. Chemical perturbation of endosomal acidification in the neurite or somal compartment further shows that establishment of infection requires pH-dependent fusion of virions at the cell body. These findings correlate infectivity to existing single particle evidence of long-range endosomal transport of RABV and clathrin dependent uptake at the plasma membrane.
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Affiliation(s)
- Silvia Piccinotti
- Department of Microbiology and Immunobiology, Program in Virology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Sean P. J. Whelan
- Department of Microbiology and Immunobiology, Program in Virology, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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19
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Debaisieux S, Encheva V, Chakravarty P, Snijders AP, Schiavo G. Analysis of Signaling Endosome Composition and Dynamics Using SILAC in Embryonic Stem Cell-Derived Neurons. Mol Cell Proteomics 2016; 15:542-57. [PMID: 26685126 PMCID: PMC4739672 DOI: 10.1074/mcp.m115.051649] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 11/18/2015] [Indexed: 12/22/2022] Open
Abstract
Neurons require efficient transport mechanisms such as fast axonal transport to ensure neuronal homeostasis and survival. Neurotrophins and their receptors are conveyed via fast axonal retrograde transport of signaling endosomes to the soma, where they elicit transcriptional responses. Despite the essential roles of signaling endosomes in neuronal differentiation and survival, little is known about their molecular identity, dynamics, and regulation. Gaining a better mechanistic understanding of these organelles and their kinetics is crucial, given the growing evidence linking vesicular trafficking deficits to neurodegeneration. Here, we exploited an affinity purification strategy using the binding fragment of tetanus neurotoxin (HCT) conjugated to monocrystalline iron oxide nanoparticles (MIONs), which in motor neurons, is transported in the same carriers as neurotrophins and their receptors. To quantitatively assess the molecular composition of HCT-containing signaling endosomes, we have developed a protocol for triple Stable Isotope Labeling with Amino acids in Cell culture (SILAC) in embryonic stem cell-derived motor neurons. After HCT internalization, retrograde carriers were magnetically isolated at different time points and subjected to mass-spectrometry and Gene Ontology analyses. This purification strategy is highly specific, as confirmed by the presence of essential regulators of fast axonal transport in the make-up of these organelles. Our results indicate that signaling endosomes undergo a rapid maturation with the acquisition of late endosome markers following a specific time-dependent kinetics. Strikingly, signaling endosomes are specifically enriched in proteins known to be involved in neurodegenerative diseases and neuroinfection. Moreover, we highlighted the presence of novel components, whose precise temporal recruitment on signaling endosomes might be essential for proper sorting and/or transport of these organelles. This study provides the first quantitative proteomic analysis of signaling endosomes isolated from motor neurons and allows the assembly of a functional map of these axonal carriers involved in long-range neuronal signaling.
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Affiliation(s)
- Solène Debaisieux
- From the ‡Molecular NeuroPathobiology Laboratory, Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Vesela Encheva
- ¶Protein Analysis and Proteomics Group, The Francis Crick Institute, South Mimms EN6 3LD, UK
| | - Probir Chakravarty
- §Bioinformatics and Biostatistics Group, The Francis Crick Institute, London WC2A 3LY, UK
| | - Ambrosius P Snijders
- ¶Protein Analysis and Proteomics Group, The Francis Crick Institute, South Mimms EN6 3LD, UK
| | - Giampietro Schiavo
- From the ‡Molecular NeuroPathobiology Laboratory, Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, University College London, London WC1N 3BG, UK;
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20
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Rummel A. Two Feet on the Membrane: Uptake of Clostridial Neurotoxins. Curr Top Microbiol Immunol 2016; 406:1-37. [PMID: 27921176 DOI: 10.1007/82_2016_48] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
The extraordinary potency of botulinum neurotoxins (BoNT) and tetanus neurotoxin (TeNT) is mediated by their high neurospecificity, targeting peripheral cholinergic motoneurons leading to flaccid and spastic paralysis, respectively, and successive respiratory failure. Complex polysialo gangliosides accumulate BoNT and TeNT on the plasma membrane. The ganglioside binding in BoNT/A, B, E, F, G, and TeNT occurs via a conserved ganglioside-binding pocket within the most carboxyl-terminal 25 kDa domain HCC, whereas BoNT/C, DC, and D display here two different ganglioside binding sites. This enrichment step facilitates subsequent binding of BoNT/A, B, DC, D, E, F, and G to the intraluminal domains of the synaptic vesicle glycoprotein 2 (SV2) isoforms A-C and synaptotagmin-I/-II, respectively. Whereas an induced α-helical 20-mer Syt peptide binds via side chain interactions to the tip of the HCC domain of BoNT/B, DC and G, the preexisting, quadrilateral β-sheet helix of SV2C-LD4 binds the clinically most relevant serotype BoNT/A mainly through backbone-backbone interactions at the interface of HCC and HCN. In addition, the conserved, complex N559-glycan branch of SV2C establishes extensive interactions with BoNT/A resulting in delayed dissociation providing BoNT/A more time for endocytosis into synaptic vesicles. An analogous interaction occurs between SV2A/B and BoNT/E. Altogether, the nature of BoNT-SV2 recognition clearly differs from BoNT-Syt. Subsequently, the synaptic vesicle is recycled and the bound neurotoxin is endocytosed. Acidification of the vesicle lumen triggers membrane insertion of the translocation domain, pore formation, and finally translocation of the enzymatically active light chain into the neuronal cytosol to halt release of neurotransmitters.
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Affiliation(s)
- Andreas Rummel
- Institut Für Toxikologie, Medizinische Hochschule Hannover, 30623, Hannover, Germany.
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21
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Gibbs KL, Kalmar B, Sleigh JN, Greensmith L, Schiavo G. In vivo imaging of axonal transport in murine motor and sensory neurons. J Neurosci Methods 2015; 257:26-33. [PMID: 26424507 PMCID: PMC4666412 DOI: 10.1016/j.jneumeth.2015.09.018] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 09/11/2015] [Accepted: 09/16/2015] [Indexed: 12/12/2022]
Abstract
BACKGROUND Axonal transport is essential for neuronal function and survival. Defects in axonal transport have been identified as an early pathological feature in several disorders of the nervous system. The visualisation and quantitative analysis of axonal transport in vivo in rodent models of neurological disease is therefore crucial to improve our understanding of disease pathogenesis and for the identification of novel therapeutics. NEW METHOD Here, we describe a method for the in vivo imaging of axonal transport of signalling endosomes in the sciatic nerve of live, anaesthetised mice. RESULTS This method allows the multiparametric, quantitative analysis of in vivo axonal transport in motor and sensory neurons of adult mice in control conditions and during disease progression. COMPARISON WITH EXISTING METHODS Previous in vivo imaging of the axonal transport of signalling endosomes has been limited to studies in nerve explant preparations or non-invasive approaches using magnetic resonance imaging; techniques that are hampered by major drawbacks such as tissue damage and low temporal and spatial resolution. This new method allows live imaging of the axonal transport of single endosomes in the sciatic nerve in situ and a more sensitive analysis of axonal transport kinetics than previous approaches. CONCLUSIONS The method described in this paper allows an in-depth analysis of the characteristics of axonal transport in both motor and sensory neurons in vivo. It enables the detailed study of alterations in axonal transport in rodent models of neurological diseases and can be used to identify novel pharmacological modifiers of axonal transport.
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Affiliation(s)
- Katherine L Gibbs
- Sobell Department of Motor Neuroscience & Movement Disorders, UCL Institute of Neurology, University College London, Queen Square, London WC1 N 3BG, UK.
| | - Bernadett Kalmar
- Sobell Department of Motor Neuroscience & Movement Disorders, UCL Institute of Neurology, University College London, Queen Square, London WC1 N 3BG, UK.
| | - James N Sleigh
- Sobell Department of Motor Neuroscience & Movement Disorders, UCL Institute of Neurology, University College London, Queen Square, London WC1 N 3BG, UK; Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK.
| | - Linda Greensmith
- Sobell Department of Motor Neuroscience & Movement Disorders, UCL Institute of Neurology, University College London, Queen Square, London WC1 N 3BG, UK.
| | - Giampietro Schiavo
- Sobell Department of Motor Neuroscience & Movement Disorders, UCL Institute of Neurology, University College London, Queen Square, London WC1 N 3BG, UK.
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22
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Connan C, Varela-Chavez C, Mazuet C, Molgó J, Haustant GM, Disson O, Lecuit M, Vandewalle A, Popoff MR. Translocation and dissemination to target neurons of botulinum neurotoxin type B in the mouse intestinal wall. Cell Microbiol 2015; 18:282-301. [DOI: 10.1111/cmi.12502] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 08/18/2015] [Accepted: 08/18/2015] [Indexed: 12/19/2022]
Affiliation(s)
- Chloé Connan
- Unité des Bactéries anaérobies et Toxines; Institut Pasteur; Paris 75724 France
| | | | - Christelle Mazuet
- Unité des Bactéries anaérobies et Toxines; Institut Pasteur; Paris 75724 France
| | - Jordi Molgó
- Service d'Ingénierie Moléculaire des Protéines, Laboratoire de Toxinologie Moléculaire et Biotechnologies; CEA, iBiTec-S; bâtiment 152, courrier N° 24 Gif-sur-Yvette 91191 France
- Institut des Neurosciences Paris-Saclay, UMR 9197; CNRS; Gif-sur-Yvette 91190 France
| | | | - Olivier Disson
- Unité de Biologie des Infections; Institut Pasteur; Paris 75724 France
| | - Marc Lecuit
- Unité de Biologie des Infections; Institut Pasteur; Paris 75724 France
| | - Alain Vandewalle
- Centre de Recherche sur l'Inflammation (CRI), UMRS 1149; Université Paris 7-Denis Diderot; site Bichat Paris 75018 France
| | - Michel R. Popoff
- Unité des Bactéries anaérobies et Toxines; Institut Pasteur; Paris 75724 France
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23
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Rummel A. The long journey of botulinum neurotoxins into the synapse. Toxicon 2015; 107:9-24. [PMID: 26363288 DOI: 10.1016/j.toxicon.2015.09.009] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 08/27/2015] [Accepted: 09/08/2015] [Indexed: 01/09/2023]
Abstract
Botulinum neurotoxins (BoNT) cause the disease botulism, a flaccid paralysis of the muscle. They are also very effective, widely used medicines applied locally in sub-nanogram quantities. BoNTs are released together with several non-toxic, associated proteins as progenitor toxin complexes (PCT) by Clostridium botulinum to become highly potent oral poisons ingested via contaminated food. They block the neurotransmission in susceptible animals and humans already in nanogram quantities due to their specific ability to enter motoneurons and to cleave only selected neuronal proteins involved in neuroexocytosis. BoNTs have developed a sophisticated strategy to passage the gastrointestinal tract and to be absorbed in the intestine of the host to finally attack neurons. A non-toxic non-hemagglutinin (NTNHA) forms a binary complex with BoNT to protect it from gastrointestinal degradation. This binary M-PTC is one component of the bi-modular 14-subunit ∼760 kDa large progenitor toxin complex. The other component is the structurally and functionally independent dodecameric hemagglutinin (HA) complex which facilitates the absorption on the intestinal epithelium by glycan binding. Subsequent to its transcytosis the HA complex disrupts the tight junction of the intestinal barrier from the basolateral side by binding to E-cadherin. Now, the L-PTC can also enter the circulation by paracellular routes in much larger quantities. From here, the dissociated BoNTs reach the neuromuscular junction and accumulate via interaction with polysialo gangliosides, complex glycolipids, on motoneurons at the neuromuscular junction. Subsequently, additional specific binding to luminal segments of synaptic vesicles proteins like SV2 and synaptotagmin leads to their uptake. Finally, the neurotoxins shut down the synaptic vesicle cycle, which they had exploited before to enter their target cells, via specific cleavage of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, which constitute the core components of the cellular membrane fusion machinery.
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Affiliation(s)
- Andreas Rummel
- Institut für Toxikologie, Medizinische Hochschule Hannover, 30623 Hannover, Germany.
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24
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Brüggemann H, Brzuszkiewicz E, Chapeton-Montes D, Plourde L, Speck D, Popoff MR. Genomics of Clostridium tetani. Res Microbiol 2015; 166:326-31. [DOI: 10.1016/j.resmic.2015.01.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 01/08/2015] [Accepted: 01/13/2015] [Indexed: 10/24/2022]
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25
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The synaptotagmin juxtamembrane domain is involved in neuroexocytosis. FEBS Open Bio 2015; 5:388-96. [PMID: 25973365 PMCID: PMC4427626 DOI: 10.1016/j.fob.2015.04.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 04/21/2015] [Accepted: 04/23/2015] [Indexed: 12/21/2022] Open
Abstract
The highly cationic juxtamembrane segment of synaptotagmin juxtamembrane domain was synthesized. This peptide inhibits neurotransmitter release at the neuromuscular junction of mice and Drosophila. This peptide localizes mainly on the presynaptic membrane. The synaptotagmin juxtamembrane peptide binds monophosphoinositides in a Ca2+-independent manner. The juxtamembrane segment of synaptotagmin may contribute to the formation of the hemifusion intermediate.
Synaptotagmin is a synaptic vesicle membrane protein which changes conformation upon Ca2+ binding and triggers the fast neuroexocytosis that takes place at synapses. We have synthesized a series of peptides corresponding to the sequence of the cytosolic juxtamembrane domain of synaptotagmin, which is highly conserved among different isoforms and animal species, with or without either a hexyl hydrophobic chain or the hexyl group plus a fluorescein moiety. We show that these peptides inhibit neurotransmitter release, that they localize on the presynaptic membrane of the motor axon terminal at the neuromuscular junction and that they bind monophosphoinositides in a Ca2+-independent manner. Based on these findings, we propose that the juxtamembrane cytosolic domain of synaptotagmin binds the cytosolic layer of the presynaptic membrane at rest. This binding brings synaptic vesicles and plasma membrane in a very close apposition, favouring the formation of hemifusion intermediates that enable rapid vesicle fusion.
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Key Words
- Anionic phospholipids
- JMS, juxtamembrane segment
- Juxtamembrane domain
- NMJ, neuromuscular junction
- Neuroexocytosis
- Neuromuscular junction
- PM, presynaptic membrane
- SV, synaptic vesicles
- Synaptotagmin
- Syt, synaptotagmin
- TM, transmembrane
- h-FJMS, hexyl fluorescent juxtamembrane segment
- h-JMS, hexyl juxtamembrane segment
- h-sJMS, hexyl scrambled juxtamembrane segment
- α-BTX, alpha-bungarotoxin
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Recycling endosomes undergo rapid closure of a fusion pore on exocytosis in neuronal dendrites. J Neurosci 2014; 34:11106-18. [PMID: 25122907 DOI: 10.1523/jneurosci.0799-14.2014] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Exocytosis of recycling endosomes (REs) represents the last step of receptor and membrane recycling, a fundamental process involved in many aspects of cell physiology. In neurons, it is involved in the control of cell polarity and synaptic plasticity and is locally and tightly regulated. However, its molecular mechanisms are still poorly understood. We have imaged single exocytosis events of REs in rat hippocampal neurons in culture transfected with three types of receptors tagged with the pH-sensitive GFP mutant superecliptic phluorin. We found that exocytosis events are grouped into two categories: (1) short burst events in which receptors diffuse into the plasma membrane in a few seconds; and (2) long display events in which receptors remain visible and clustered after exocytosis for many seconds. Display events are much rarer in non-neuronal cells, such as fibroblasts and astrocytes. Using two-color imaging and fast extracellular solution changes, we show that display events correspond to the rapid opening and closing of a fusion pore (or "kiss-and-run") with a median opening time of 2.6 s, which restricts the diffusion of multiple receptor types and bound cargo. Moreover, the RE marker Rab11 remains enriched after display exocytosis events and controls the mode of RE exocytosis. Finally, a given RE can undergo multiple rounds of display exocytosis. The last step of recycling can thus be controlled in neurons for the selective delivery of receptors at the cell surface.
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27
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Blum FC, Tepp WH, Johnson EA, Barbieri JT. Multiple domains of tetanus toxin direct entry into primary neurons. Traffic 2014; 15:1057-65. [PMID: 25040808 DOI: 10.1111/tra.12197] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 07/11/2014] [Accepted: 07/11/2014] [Indexed: 12/11/2022]
Abstract
Tetanus toxin elicits spastic paralysis by cleaving VAMP-2 to inhibit neurotransmitter release in inhibitory neurons of the central nervous system. As the retrograde transport of tetanus neurotoxin (TeNT) from endosomes has been described, the initial steps that define how TeNT initiates trafficking to the retrograde system are undefined. This study examines TeNT entry into primary cultured cortical neurons by total internal reflection fluorescence (TIRF) microscopy. The initial association of TeNT with the plasma membrane was dependent upon ganglioside binding, but segregated from synaptophysin1 (Syp1), a synaptic vesicle (SV) protein. TeNT entry was unaffected by membrane depolarization and independent of SV cycling, whereas entry of the receptor-binding domain of TeNT (HCR/T) was stimulated by membrane depolarization and inhibited by blocking SV cycling. Measurement of the incidence of colocalization showed that TeNT segregated from Syp1, whereas HCR/T colocalized with Syp1. These studies show that while the HCR defines the initial association of TeNT with the cell membrane, regions outside the HCR define how TeNT enters neurons independent of SV cycling. This provides a basis for the unique entry of botulinum toxin and tetanus toxin into neurons.
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Affiliation(s)
- Faith C Blum
- Microbiology and Molecular Genetics, Medical College of Wisconsin, 8701 Watertown Plank Rd., Milwaukee, WI, 53226, USA
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Terenzio M, Golding M, Russell MRG, Wicher KB, Rosewell I, Spencer-Dene B, Ish-Horowicz D, Schiavo G. Bicaudal-D1 regulates the intracellular sorting and signalling of neurotrophin receptors. EMBO J 2014; 33:1582-98. [PMID: 24920579 PMCID: PMC4198053 DOI: 10.15252/embj.201387579] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 03/14/2014] [Accepted: 04/23/2014] [Indexed: 12/31/2022] Open
Abstract
We have identified a new function for the dynein adaptor Bicaudal D homolog 1 (BICD1) by screening a siRNA library for genes affecting the dynamics of neurotrophin receptor-containing endosomes in motor neurons (MNs). Depleting BICD1 increased the intracellular accumulation of brain-derived neurotrophic factor (BDNF)-activated TrkB and p75 neurotrophin receptor (p75(NTR)) by disrupting the endosomal sorting, reducing lysosomal degradation and increasing the co-localisation of these neurotrophin receptors with retromer-associated sorting nexin 1. The resulting re-routing of active receptors increased their recycling to the plasma membrane and altered the repertoire of signalling-competent TrkB isoforms and p75(NTR) available for ligand binding on the neuronal surface. This resulted in attenuated, but more sustained, AKT activation in response to BDNF stimulation. These data, together with our observation that Bicd1 expression is restricted to the developing nervous system when neurotrophin receptor expression peaks, indicate that BICD1 regulates neurotrophin signalling by modulating the endosomal sorting of internalised ligand-activated receptors.
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Affiliation(s)
- Marco Terenzio
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, UK
| | - Matthew Golding
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, UK
| | - Matthew R G Russell
- Electron Microscopy Laboratory, Cancer Research UK London Research Institute, London, UK
| | - Krzysztof B Wicher
- Developmental Genetics Laboratory, Cancer Research UK London Research Institute, London, UK
| | - Ian Rosewell
- Transgenic Services laboratory, Cancer Research UK London Research Institute, London, UK
| | - Bradley Spencer-Dene
- Experimental Histopathology Laboratory, Cancer Research UK London Research Institute, London, UK
| | - David Ish-Horowicz
- Developmental Genetics Laboratory, Cancer Research UK London Research Institute, London, UK
| | - Giampietro Schiavo
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, UK Sobell Department of Motor Neuroscience & Movement Disorders, UCL-Institute of Neurology, University College London, London, UK
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29
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Terenzio M, Golding M, Schiavo G. siRNA screen of ES cell-derived motor neurons identifies novel regulators of tetanus toxin and neurotrophin receptor trafficking. Front Cell Neurosci 2014; 8:140. [PMID: 24904285 PMCID: PMC4033017 DOI: 10.3389/fncel.2014.00140] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 05/01/2014] [Indexed: 11/21/2022] Open
Abstract
Neurons rely on the long-range transport of several signaling molecules such as neurotrophins and their receptors, which are required for neuronal development, function and survival. However, the nature of the machinery controlling the trafficking of signaling endosomes containing activated neurotrophin receptors has not yet been completely elucidated. We aimed to identify new players involved in the dynamics of neurotrophin signaling endosomes using a medium-throughput unbiased siRNA screening approach to quantify the intracellular accumulation of two fluorescently tagged reporters: the binding fragment of tetanus neurotoxin (HCT), and an antibody directed against the neurotrophin receptor p75NTR. This screen performed in motor neurons differentiated from mouse embryonic stem (ES) cells identified a number of candidate genes encoding molecular motors and motor adaptor proteins involved in regulating the intracellular trafficking of these probes. Bicaudal D homolog 1 (BICD1), a molecular motor adaptor with pleiotropic roles in intracellular trafficking, was selected for further analyses, which revealed that BICD1 regulates the intracellular trafficking of HCT and neurotrophin receptors and likely plays an important role in nervous system development and function.
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Affiliation(s)
- Marco Terenzio
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute London, UK
| | - Matthew Golding
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute London, UK
| | - Giampietro Schiavo
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute London, UK ; Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, University College London London, UK
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Hislop JN, Islam TA, Eleftheriadou I, Carpentier DCJ, Trabalza A, Parkinson M, Schiavo G, Mazarakis ND. Rabies virus envelope glycoprotein targets lentiviral vectors to the axonal retrograde pathway in motor neurons. J Biol Chem 2014; 289:16148-63. [PMID: 24753246 DOI: 10.1074/jbc.m114.549980] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Rabies pseudotyped lentiviral vectors have great potential in gene therapy, not least because of their ability to transduce neurons following their distal axonal application. However, very little is known about the molecular processes that underlie their retrograde transport and cell transduction. Using multiple labeling techniques and confocal microscopy, we demonstrated that pseudotyping with rabies virus envelope glycoprotein (RV-G) enabled the axonal retrograde transport of two distinct subtypes of lentiviral vector in motor neuron cultures. Analysis of this process revealed that these vectors trafficked through Rab5-positive endosomes and accumulated within a non-acidic Rab7 compartment. RV-G pseudotyped vectors were co-transported with both the tetanus neurotoxin-binding fragment and the membrane proteins thought to mediate rabies virus endocytosis (neural cell adhesion molecule, nicotinic acetylcholine receptor, and p75 neurotrophin receptor), thus demonstrating that pseudotyping with RV-G targets lentiviral vectors for transport along the same pathway exploited by several toxins and viruses. Using motor neurons cultured in compartmentalized chambers, we demonstrated that axonal retrograde transport of these vectors was rapid and efficient; however, it was not able to transduce the targeted neurons efficiently, suggesting that impairment in processes occurring after arrival of the viral vector in the soma is responsible for the low transduction efficiency seen in vivo, which suggests a novel area for improvement of gene therapy vectors.
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Affiliation(s)
- James N Hislop
- From Gene Therapy, Centre for Neuroinflammation and Neurodegeneration, Division of Brain Sciences, Department of Medicine, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom
| | - Tarin A Islam
- From Gene Therapy, Centre for Neuroinflammation and Neurodegeneration, Division of Brain Sciences, Department of Medicine, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom
| | - Ioanna Eleftheriadou
- From Gene Therapy, Centre for Neuroinflammation and Neurodegeneration, Division of Brain Sciences, Department of Medicine, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom
| | - David C J Carpentier
- From Gene Therapy, Centre for Neuroinflammation and Neurodegeneration, Division of Brain Sciences, Department of Medicine, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom
| | - Antonio Trabalza
- From Gene Therapy, Centre for Neuroinflammation and Neurodegeneration, Division of Brain Sciences, Department of Medicine, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom
| | - Michael Parkinson
- Molecular NeuroPathoBiology Laboratory, Cancer Research UK London Research Institute, Lincoln's Inn Fields Laboratories, 44 Lincoln's Inn Fields, London WC2A 3LY, United Kingdom, and
| | - Giampietro Schiavo
- Molecular NeuroPathoBiology Laboratory, Cancer Research UK London Research Institute, Lincoln's Inn Fields Laboratories, 44 Lincoln's Inn Fields, London WC2A 3LY, United Kingdom, and Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, University College London, Queen Square, London WC1N 3BG, United Kingdom
| | - Nicholas D Mazarakis
- From Gene Therapy, Centre for Neuroinflammation and Neurodegeneration, Division of Brain Sciences, Department of Medicine, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom,
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31
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Specific retrograde transduction of spinal motor neurons using lentiviral vectors targeted to presynaptic NMJ receptors. Mol Ther 2014; 22:1285-1298. [PMID: 24670531 DOI: 10.1038/mt.2014.49] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 03/16/2014] [Indexed: 12/18/2022] Open
Abstract
To understand how receptors are involved in neuronal trafficking and to be able to utilize them for specific targeting via the peripheral route would be of great benefit. Here, we describe the generation of novel lentiviral vectors with tropism to motor neurons that were made by coexpressing onto the lentiviral surface a fusogenic glycoprotein (mutated sindbis G) and an antibody against a cell-surface receptor (Thy1.1, p75(NTR), or coxsackievirus and adenovirus receptor) on the presynaptic terminal of the neuromuscular junction. These vectors exhibit binding specificity and efficient transduction of receptor positive cell lines and primary motor neurons in vitro. Targeting of each of these receptors conferred to these vectors the capability of being transported retrogradely from the axonal tip, leading to transduction of motor neurons in vitro in compartmented microfluidic cultures. In vivo delivery of coxsackievirus and adenovirus receptor-targeted vectors in leg muscles of mice resulted in predicted patterns of motor neuron labeling in lumbar spinal cord. This opens up the clinical potential of these vectors for minimally invasive administration of central nervous system-targeted therapeutics in motor neuron diseases.
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32
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Schmieg N, Menendez G, Schiavo G, Terenzio M. Signalling endosomes in axonal transport: Travel updates on the molecular highway. Semin Cell Dev Biol 2014; 27:32-43. [DOI: 10.1016/j.semcdb.2013.10.004] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2013] [Revised: 10/17/2013] [Accepted: 10/19/2013] [Indexed: 01/11/2023]
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33
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Abstract
Vectors derived from the canine adenovirus serotype 2 (CAV-2) possess a high neurotropism and efficient retrograde transport that lead to widespread neuronal transduction in the central nervous system (CNS) of various animals. These abilities are due to the engagement of virions to the coxsackievirus and adenovirus receptor at the surface of neurons, which is linked to the endocytic and axonal transport machineries. The trafficking of CAV-2 and the coxsackievirus and adenovirus receptor (CAR) can be visualized ex vivo by incubating primary neurons (e.g., motoneurons and hippocampal neurons) with fluorescently labeled virions or recombinant viral proteins. Using this approach, we could recapitulate the mechanisms responsible for long-range transport of adenovirus in neurons.
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Affiliation(s)
- Charleine Zussy
- Institut de Génétique Moléculaire de Montpellier, CNRS UMR 5535, Universités de Montpellier I & II, Montpellier, France
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34
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Entry of a recombinant, full-length, atoxic tetanus neurotoxin into Neuro-2a cells. Infect Immun 2013; 82:873-81. [PMID: 24478100 DOI: 10.1128/iai.01539-13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Tetanus neurotoxin (TeNT) and botulinum neurotoxin (BoNT) are clostridial neurotoxins (CNTs) responsible for the paralytic diseases tetanus and botulism, respectively. CNTs are AB toxins with an N-terminal zinc-metalloprotease light chain that is linked by a disulfide bond to a C-terminal heavy chain that includes a translocation domain and a receptor-binding domain (HCR). Current models predict that the HCR defines how CNTs enter and traffic in neurons. Recent studies implicate that domains outside the HCR contribute to CNT trafficking in neurons. In the current study, a recombinant, full-length TeNT derivative, TeNT(RY), was engineered to analyze TeNT cell entry. TeNT(RY) was atoxic in a mouse challenge model. Using Neuro-2a cells, a mouse neuroblastoma cell line, TeNT HCR (HCR/T) and TeNT(RY) were found to bind gangliosides with similar affinities and specificities, consistent with the HCR domain containing receptor binding function. Temporal studies showed that HCR/T and TeNT(RY) entered Neuro-2a cells slower than the HCR of BoNT/A (HCR/A), transferrin, and cholera toxin B. Intracellular localization showed that neither HCR/T nor TeNT(RY) localized with HCR/A or synaptic vesicle protein 2, the protein receptor for HCR/A. HCR/T and TeNT(RY) exhibited only partial intracellular colocalization, indicating that regions outside the HCR contribute to the intracellular TeNT trafficking. TeNT may require this complex functional entry organization to target neurons in the central nervous system.
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35
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Höltje M, Schulze S, Strotmeier J, Mahrhold S, Richter K, Binz T, Bigalke H, Ahnert-Hilger G, Rummel A. Exchanging the minimal cell binding fragments of tetanus neurotoxin in botulinum neurotoxin A and B impacts their toxicity at the neuromuscular junction and central neurons. Toxicon 2013; 75:108-21. [DOI: 10.1016/j.toxicon.2013.06.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 06/09/2013] [Accepted: 06/17/2013] [Indexed: 12/20/2022]
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36
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Lemichez E, Barbieri JT. General aspects and recent advances on bacterial protein toxins. Cold Spring Harb Perspect Med 2013; 3:a013573. [PMID: 23378599 DOI: 10.1101/cshperspect.a013573] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Bacterial pathogens produce protein toxins to influence host-pathogen interactions and tip the outcome of these encounters toward the benefit of the pathogen. Protein toxins modify host-specific targets through posttranslational modifications (PTMs) or noncovalent interactions that may inhibit or activate host cell physiology to benefit the pathogen. Recent advances have identified new PTMs and host targets for toxin action. Understanding the mechanisms of toxin action provides a basis to develop vaccines and therapies to combat bacterial pathogens and to develop new strategies to use toxin derivatives for the treatment of human disease.
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Affiliation(s)
- Emmanuel Lemichez
- INSERM, U1065, Centre Méditerranéen de Médecine Moléculaire, Microbial Toxins in Host-Pathogen Interactions, C3M, Université de Nice-Sophia-Antipolis, UFR Médecine, 06204 Nice, France.
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37
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38
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Restani L, Giribaldi F, Manich M, Bercsenyi K, Menendez G, Rossetto O, Caleo M, Schiavo G. Botulinum neurotoxins A and E undergo retrograde axonal transport in primary motor neurons. PLoS Pathog 2012; 8:e1003087. [PMID: 23300443 PMCID: PMC3531519 DOI: 10.1371/journal.ppat.1003087] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 11/02/2012] [Indexed: 11/18/2022] Open
Abstract
The striking differences between the clinical symptoms of tetanus and botulism have been ascribed to the different fate of the parental neurotoxins once internalised in motor neurons. Tetanus toxin (TeNT) is known to undergo transcytosis into inhibitory interneurons and block the release of inhibitory neurotransmitters in the spinal cord, causing a spastic paralysis. In contrast, botulinum neurotoxins (BoNTs) block acetylcholine release at the neuromuscular junction, therefore inducing a flaccid paralysis. Whilst overt experimental evidence supports the sorting of TeNT to the axonal retrograde transport pathway, recent findings challenge the established view that BoNT trafficking is restricted to the neuromuscular junction by highlighting central effects caused by these neurotoxins. These results suggest a more complex scenario whereby BoNTs also engage long-range trafficking mechanisms. However, the intracellular pathways underlying this process remain unclear. We sought to fill this gap by using primary motor neurons either in mass culture or differentiated in microfluidic devices to directly monitor the endocytosis and axonal transport of full length BoNT/A and BoNT/E and their recombinant binding fragments. We show that BoNT/A and BoNT/E are internalised by spinal cord motor neurons and undergo fast axonal retrograde transport. BoNT/A and BoNT/E are internalised in non-acidic axonal carriers that partially overlap with those containing TeNT, following a process that is largely independent of stimulated synaptic vesicle endo-exocytosis. Following intramuscular injection in vivo, BoNT/A and TeNT displayed central effects with a similar time course. Central actions paralleled the peripheral spastic paralysis for TeNT, but lagged behind the onset of flaccid paralysis for BoNT/A. These results suggest that the fast axonal retrograde transport compartment is composed of multifunctional trafficking organelles orchestrating the simultaneous transfer of diverse cargoes from nerve terminals to the soma, and represents a general gateway for the delivery of virulence factors and pathogens to the central nervous system. Botulinum neurotoxins are the most toxic molecules known to mankind, and as a result, are currently listed among the top bio-threats. However, their ability to bind specifically to neurons and their inhibitory effects on regulated secretion prompted their clinical use in pathologies characterised by increased muscular tone, such as dystonia and various forms of spasticity, or abnormal secretion, such as drooling and excessive sweating, to cite a few. As a consequence, botulinum neurotoxin A, which is the serotype most commonly used in human therapy, has become the treatment of choice for an ever-expanding number of pathological and non-pathological (e.g. cosmetic) conditions. All current indications show that the systemic effects and toxicity of botulinum neurotoxin A are minimised by the specific route of administration (local injection) and the low diffusion of this molecule in tissues. However, recent reports suggest that in contrast to this common belief, botulinum neurotoxin A is able to reach distal sites in the body and may have previously unanticipated effects in the central nervous system. In this study, we demonstrate that botulinum neurotoxin A and E enter alternative endocytic pathway(s) in addition to synaptic vesicle recycling, and undergo long-range transport in a non degradative compartment in spinal cord motor neurons. Our results show that axonal retrograde transport is a common pathway for the dissemination in the central nervous system of pathogens and virulence factors important for human and animal health.
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Affiliation(s)
- Laura Restani
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
- CNR, Neuroscience Institute, Pisa, Italy
| | - Francesco Giribaldi
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
| | - Maria Manich
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
- Institut Pasteur, Unité des Bactéries anaérobies et Toxines, Paris, France
| | - Kinga Bercsenyi
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
| | - Guillermo Menendez
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
| | - Ornella Rossetto
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | | | - Giampietro Schiavo
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
- * E-mail:
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Schellingerhout D, LeRoux LG, Hobbs BP, Bredow S. Impairment of retrograde neuronal transport in oxaliplatin-induced neuropathy demonstrated by molecular imaging. PLoS One 2012; 7:e45776. [PMID: 23029238 PMCID: PMC3447809 DOI: 10.1371/journal.pone.0045776] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 08/23/2012] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND AND PURPOSE The purpose of our study was to utilize a molecular imaging technology based on the retrograde axonal transport mechanism (neurography), to determine if oxaliplatin-induced neurotoxicity affects retrograde axonal transport in an animal model. MATERIALS AND METHODS Mice (n = 8/group) were injected with a cumulative dose of 30 mg/kg oxaliplatin (sufficient to induce neurotoxicity) or dextrose control injections. Intramuscular injections of Tetanus Toxin C-fragment (TTc) labeled with Alexa 790 fluorescent dye were done (15 ug/20 uL) in the left calf muscles, and in vivo fluorescent imaging performed (0-60 min) at baseline, and then weekly for 5 weeks, followed by 2-weekly imaging out to 9 weeks. Tissues were harvested for immunohistochemical analysis. RESULTS With sham treatment, TTc transport causes fluorescent signal intensity over the thoracic spine to increase from 0 to 60 minutes after injection. On average, fluorescence signal increased 722%+/-117% (Mean+/-SD) from 0 to 60 minutes. Oxaliplatin treated animals had comparable transport at baseline (787%+/-140%), but transport rapidly decreased through the course of the study, falling to 363%+/-88%, 269%+/-96%, 191%+/-58%, 121%+/-39%, 75%+/-21% with each successive week and stabilizing around 57% (+/-15%) at 7 weeks. Statistically significant divergence occurred at approximately 3 weeks (p≤0.05, linear mixed-effects regression model). Quantitative immuno-fluorescence histology with a constant cutoff threshold showed reduced TTc in the spinal cord at 7 weeks for treated animals versus controls (5.2 Arbitrary Units +/-0.52 vs 7.1 AU +/-1.38, p<0.0004, T-test). There was no significant difference in neural cell mass between the two groups as shown with NeuN staining (10.2+/-1.21 vs 10.5 AU +/-1.53, p>0.56, T-test). CONCLUSION We show-for the first time to our knowledge-that neurographic in vivo molecular imaging can demonstrate imaging changes in a model of oxaliplatin-induced neuropathy. Impaired retrograde neural transport is suggested to be an important part of the pathophysiology of oxaliplatin-induced neuropathy.
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Affiliation(s)
- Dawid Schellingerhout
- Department of Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
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Wang J, Zurawski TH, Meng J, Lawrence GW, Aoki KR, Wheeler L, Dolly JO. Novel chimeras of botulinum and tetanus neurotoxins yield insights into their distinct sites of neuroparalysis. FASEB J 2012; 26:5035-48. [PMID: 22942075 DOI: 10.1096/fj.12-210112] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Botulinum neurotoxin (BoNT) A or E and tetanus toxin (TeTx) bind to motor-nerve endings and undergo distinct trafficking; their light-chain (LC) proteases cleave soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) peripherally or centrally and cause flaccid or spastic paralysis, respectively. To seek protein domains responsible for local blockade of transmitter release (BoNTs) rather than retroaxonal transport to spinal neurons (TeTx), their acceptor-binding moieties (H(C))--or in one case, heavy chain (HC)--were exchanged by gene recombination. Each chimera, expressed and purified from Escherichia coli, entered rat cerebellar neurons to cleave their substrates, blocked in vitro nerve-induced muscle contractions, and produced only flaccid paralysis in mice. Thus, the local cytosolic delivery of BoNT/A or BoNT/E proteases and the contrasting retrograde transport of TeTx are not specified solely by their HC or H(C); BoNT/A LC translocated locally irrespective of being targeted by either of the latter TeTx domains. In contrast, BoNT/E protease fused to a TeTx enzymatically inactive mutant (TeTIM) caused spastic paralysis and cleaved SNAP-25 in spinal cord but not the injected muscle. Apparently, TeTIM precludes cytosolic release of BoNT/E protease at motor nerve endings. It is deduced that the LCs of the toxins, acting in conjunction with HC domains, dictate their local or distant destinations.
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Affiliation(s)
- Jiafu Wang
- International Centre for Neurotherapeutics, Dublin City University, Glasnevin, Dublin 9, Ireland
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Couesnon A, Molgó J, Connan C, Popoff MR. Preferential entry of botulinum neurotoxin A Hc domain through intestinal crypt cells and targeting to cholinergic neurons of the mouse intestine. PLoS Pathog 2012; 8:e1002583. [PMID: 22438808 PMCID: PMC3305446 DOI: 10.1371/journal.ppat.1002583] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Accepted: 01/27/2012] [Indexed: 12/12/2022] Open
Abstract
Botulism, characterized by flaccid paralysis, commonly results from botulinum neurotoxin (BoNT) absorption across the epithelial barrier from the digestive tract and then dissemination through the blood circulation to target autonomic and motor nerve terminals. The trafficking pathway of BoNT/A passage through the intestinal barrier is not yet fully understood. We report that intralumenal administration of purified BoNT/A into mouse ileum segment impaired spontaneous muscle contractions and abolished the smooth muscle contractions evoked by electric field stimulation. Entry of BoNT/A into the mouse upper small intestine was monitored with fluorescent HcA (half C-terminal domain of heavy chain) which interacts with cell surface receptor(s). We show that HcA preferentially recognizes a subset of neuroendocrine intestinal crypt cells, which probably represent the entry site of the toxin through the intestinal barrier, then targets specific neurons in the submucosa and later (90–120 min) in the musculosa. HcA mainly binds to certain cholinergic neurons of both submucosal and myenteric plexuses, but also recognizes, although to a lower extent, other neuronal cells including glutamatergic and serotoninergic neurons in the submucosa. Intestinal cholinergic neuron targeting by HcA could account for the inhibition of intestinal peristaltism and secretion observed in botulism, but the consequences of the targeting to non-cholinergic neurons remains to be determined. Botulism is a severe and often fatal disease in man and animals characterized by flaccid paralysis. Clostridium botulinum produces a potent neurotoxin (botulinum neurotoxin) responsible for all the symptoms of botulism. Botulism is most often acquired by ingesting preformed botulinum neurotoxin in contaminated food or after intestinal colonization by C. botulinum under certain circumstances, such as in infant botulism, and toxin production in the intestine. The first step of the disease consists in the passage of the botulinum neurotoxin through the intestinal barrier, which is still poorly understood. We investigated the trafficking of the botulinum neurotoxin in a mouse intestinal loop model, using fluorescent HcA (half C-terminal domain of the heavy chain). We observed that HcA preferentially recognizes neuroendocrine intestinal crypt cells, which likely represent the entry site of the toxin through the intestinal barrier, then targets specific neurons, mainly cholinergic neurons, in the submucosa, and later (90–120 min) in the musculosa leading to local paralytic effects such as inhibition of intestinal peristaltism. These results represent an important advance in the understanding of the initial steps of botulism intoxication and can be the basis for the development of new specific countermeasures against botulism.
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Affiliation(s)
- Aurélie Couesnon
- Institut Pasteur, Unité des Bactéries anaérobies et Toxines, Paris, France
| | - Jordi Molgó
- CNRS, Institut de Neurobiologie Alfred Fessard – FRC2118, Laboratoire de Neurobiologie– et Développement UPR3294, Gif sur Yvette, France
| | - Chloé Connan
- Institut Pasteur, Unité des Bactéries anaérobies et Toxines, Paris, France
| | - Michel R. Popoff
- Institut Pasteur, Unité des Bactéries anaérobies et Toxines, Paris, France
- * E-mail:
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Wade A, Thomas C, Kalmar B, Terenzio M, Garin J, Greensmith L, Schiavo G. Activated leukocyte cell adhesion molecule modulates neurotrophin signaling. J Neurochem 2012; 121:575-86. [DOI: 10.1111/j.1471-4159.2012.07658.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Anna Wade
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, UK
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, Queen Square, London, UK
| | - Claire Thomas
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, UK
| | - Bernadett Kalmar
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, Queen Square, London, UK
| | - Marco Terenzio
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, UK
| | - Jerome Garin
- CEA, IRTSV, Biologie à Grande Echelle, Grenoble, France
- INSERM, U1038, Grenoble, France
- Université Joseph Fourier, Grenoble 1, France
| | - Linda Greensmith
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, Queen Square, London, UK
| | - Giampietro Schiavo
- Molecular NeuroPathobiology Laboratory, Cancer Research UK London Research Institute, London, UK
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A fast and robust method for automated analysis of axonal transport. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2011; 40:1061-9. [PMID: 21695534 DOI: 10.1007/s00249-011-0722-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 04/08/2011] [Accepted: 06/02/2011] [Indexed: 01/05/2023]
Abstract
Cargo movement along axons and dendrites is indispensable for the survival and maintenance of neuronal networks. Key parameters of this transport such as particle velocities and pausing times are often studied using kymograph construction, which converts the transport along a line of interest from a time-lapse movie into a position versus time image. Here we present a method for the automatic analysis of such kymographs based on the Hough transform, which is a robust and fast technique to extract lines from images. The applicability of the method was tested on simulated kymograph images and real data from axonal transport of synaptophysin and tetanus toxin as well as the velocity analysis of synaptic vesicle sharing between adjacent synapses in hippocampal neurons. Efficiency analysis revealed that the algorithm is able to detect a wide range of velocities and can be used at low signal-to-noise ratios. The present work enables the quantification of axonal transport parameters with high throughput with no a priori assumptions and minimal human intervention.
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Oliveira H, Pires LR, Fernandez R, Martins MCL, Simões S, Pêgo AP. Chitosan-based gene delivery vectors targeted to the peripheral nervous system. J Biomed Mater Res A 2011; 95:801-10. [PMID: 20734332 DOI: 10.1002/jbm.a.32874] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A non-toxic, targeted, simple and efficient system that can specifically transfect peripheral sensorial neurons can pave the way towards the development of new therapeutics for the treatment of peripheral neuropathies. In this study chitosan (CH), a biodegradable polymer, was used as the starting material in the design of a multicomponent vector targeted to the peripheral nervous system (PNS). Polycation-DNA complexes were optimized using imidazole- and thiol-grafted CH (CHimiSH), in order to increase transfection efficiency and allow the formation of ligand conjugated nanocomplexes, respectively. The 50 kDa non-toxic fragment from the tetanus toxin (HC), shown to interact specifically with peripheral neurons and undergo retrograde transport, was grafted to the binary complex via a bi-functional poly(ethylene glycol) (HC-PEG) reactive for the thiol moieties present in the complex surface. The targeting of the developed nanocomplexes was assessed by means of internalization and transfection studies in the ND7/23 (neuronal) vs. NIH 3T3 (fibroblast) cell lines. Targeted transfection was further confirmed in dorsal root ganglion dissociated primary cultures. A versatile, multi-component nanoparticle system that successfully targets and transfects neuronal cell lines, as well as dorsal root ganglia (DRG) primary neuron cultures was obtained for the 1.0 (w/w) HC-PEG/DNA formulation.
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Affiliation(s)
- Hugo Oliveira
- INEB, Instituto de Engenharia Biomédica, Divisão de Biomateriais, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal
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Yeh FL, Dong M, Yao J, Tepp WH, Lin G, Johnson EA, Chapman ER. SV2 mediates entry of tetanus neurotoxin into central neurons. PLoS Pathog 2010; 6:e1001207. [PMID: 21124874 PMCID: PMC2991259 DOI: 10.1371/journal.ppat.1001207] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Accepted: 10/22/2010] [Indexed: 01/18/2023] Open
Abstract
Tetanus neurotoxin causes the disease tetanus, which is characterized by rigid paralysis. The toxin acts by inhibiting the release of neurotransmitters from inhibitory neurons in the spinal cord that innervate motor neurons and is unique among the clostridial neurotoxins due to its ability to shuttle from the periphery to the central nervous system. Tetanus neurotoxin is thought to interact with a high affinity receptor complex that is composed of lipid and protein components; however, the identity of the protein receptor remains elusive. In the current study, we demonstrate that toxin binding, to dissociated hippocampal and spinal cord neurons, is greatly enhanced by driving synaptic vesicle exocytosis. Moreover, tetanus neurotoxin entry and subsequent cleavage of synaptobrevin II, the substrate for this toxin, was also dependent on synaptic vesicle recycling. Next, we identified the potential synaptic vesicle binding protein for the toxin and found that it corresponded to SV2; tetanus neurotoxin was unable to cleave synaptobrevin II in SV2 knockout neurons. Toxin entry into knockout neurons was rescued by infecting with viruses that express SV2A or SV2B. Tetanus toxin elicited the hyper excitability in dissociated spinal cord neurons - due to preferential loss of inhibitory transmission - that is characteristic of the disease. Surprisingly, in dissociated cortical cultures, low concentrations of the toxin preferentially acted on excitatory neurons. Further examination of the distribution of SV2A and SV2B in both spinal cord and cortical neurons revealed that SV2B is to a large extent localized to excitatory terminals, while SV2A is localized to inhibitory terminals. Therefore, the distinct effects of tetanus toxin on cortical and spinal cord neurons are not due to differential expression of SV2 isoforms. In summary, the findings reported here indicate that SV2A and SV2B mediate binding and entry of tetanus neurotoxin into central neurons. Tetanus neurotoxin is one of the most deadly bacterial toxins known and is the causative agent for the disease tetanus, also known as lockjaw. Tetanus neurotoxin utilizes motor neurons as a means of transport in order to enter the spinal cord. Once in the spinal cord, the toxin leaves motor neurons and enters inhibitory neurons through a “Trojan-horse” strategy, thereby preventing the release of inhibitory neurotransmitters onto motor neurons. This causes hyper-excitability of the motor neuron and excessive release of acetylcholine at the neuromuscular junction, resulting in rigid paralysis. There is a major gap in our understanding of the mechanism by which tetanus neurotoxin enters neurons. In the current study we discovered that the “Trojan-horse”, utilized by tetanus neurotoxin to enter central neurons, corresponds to recycling synaptic vesicles. Furthermore, we discovered that SV2 is critical for the binding and entry of tetanus neurotoxin into these neurons. These findings will enable further development of drugs that antagonize the action of the toxin and will also aid in the development of drug delivery systems that target spinal cord neurons.
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Affiliation(s)
- Felix L. Yeh
- Department of Physiology, Howard Hughes Medical Institute, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Min Dong
- New England Primate Research Center, Department of Microbiology and Molecular Genetics, Harvard Medical School, Southborough, Massachusetts, United States of America
| | - Jun Yao
- Department of Physiology, Howard Hughes Medical Institute, University of Wisconsin, Madison, Wisconsin, United States of America
| | - William H. Tepp
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Guangyun Lin
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Eric A. Johnson
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Edwin R. Chapman
- Department of Physiology, Howard Hughes Medical Institute, University of Wisconsin, Madison, Wisconsin, United States of America
- * E-mail:
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Toivonen JM, Oliván S, Osta R. Tetanus toxin C-fragment: the courier and the cure? Toxins (Basel) 2010; 2:2622-44. [PMID: 22069568 PMCID: PMC3153173 DOI: 10.3390/toxins2112622] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 10/28/2010] [Indexed: 12/14/2022] Open
Abstract
In many neurological disorders strategies for a specific delivery of a biological activity from the periphery to the central nervous system (CNS) remains a considerable challenge for successful therapy. Reporter assays have established that the non-toxic C-fragment of tetanus toxin (TTC), provided either as protein or encoded by non-viral naked DNA plasmid, binds pre-synaptic motor neuron terminals and can facilitate the retrograde axonal transport of desired therapeutic molecules to the CNS. Alleviated symptoms in animal models of neurological diseases upon delivery of therapeutic molecules offer a hopeful prospect for TTC therapy. This review focuses on what has been learned on TTC-mediated neuronal targeting, and discusses the recent discovery that, instead of being merely a carrier molecule, TTC itself may well harbor neuroprotective properties.
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Affiliation(s)
- Janne M Toivonen
- LAGENBIO-I3A, Veterinary School, Aragón Institute of Health Sciences (IACS), Universidad de Zaragoza, Miguel Servet 177, 50013 Zaragoza, Spain.
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Silva-Cardoso L, Caccin P, Magnabosco A, Patrón M, Targino M, Fuly A, Oliveira GA, Pereira MH, do Carmo MDGT, Souza AS, Silva-Neto MAC, Montecucco C, Atella GC. Paralytic activity of lysophosphatidylcholine from saliva of the waterbug Belostoma anurum. J Exp Biol 2010; 213:3305-10. [DOI: 10.1242/jeb.041954] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Lysophosphatidylcholine (LPC) is a major bioactive lipid that is enzymatically generated by phospholipase A2 (PLA2). Previously, we showed that LPC is present in the saliva of the blood-sucking hemipteran Rhodnius prolixus and modulates cell-signaling pathways involved in vascular biology, which aids blood feeding. Here, we show that the saliva of the predator insect Belostoma anurum contains a large number of lipids with LPC accounting for 25% of the total phospholipids. A PLA2 enzyme likely to be involved in LPC generation was characterized. The activity of this enzyme is 5-fold higher in Belostoma saliva than in other studied hemipterans, suggesting a close association with the predator feeding habits of this insect. Belostoma employs extra-oral digestion, which allows for ingestion of larger prey than itself, including small vertebrates such as amphibians and fish. Therefore, prey immobilization during digestion is essential, and we show here that Belostoma saliva and B. anurum saliva purified LPC have paralytic activity in zebrafish. This is the first evidence that lysophospholipids might play an important role in prey immobilization, in addition to contributing to blood feeding, and might have been an evolutionary acquisition that occurred long before the appearance of hematophagy in this animal group.
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Affiliation(s)
- Lívia Silva-Cardoso
- Instituto de Bioquímica Médica, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, PO Box 68041, Cidade Universitária, Ilha do Fundão, Av. Bauhínia 400, Rio de Janeiro, CEP 21941-590, RJ, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Università di Padova, Padova, Italy
| | - Paola Caccin
- Dipartimento di Scienze Biomediche, Università di Padova, Padova, Italy
| | - Anna Magnabosco
- Dipartimento di Scienze Biomediche, Università di Padova, Padova, Italy
| | - Maria Patrón
- Dipartimento di Scienze Biomediche, Università di Padova, Padova, Italy
| | - Mariane Targino
- Instituto de Bioquímica Médica, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, PO Box 68041, Cidade Universitária, Ilha do Fundão, Av. Bauhínia 400, Rio de Janeiro, CEP 21941-590, RJ, Brazil
| | - André Fuly
- Universidade Federal Fluminense, UFF, Niterói, Rio de Janeiro, Brazil
| | - Giselle A. Oliveira
- Instituto de Bioquímica Médica, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, PO Box 68041, Cidade Universitária, Ilha do Fundão, Av. Bauhínia 400, Rio de Janeiro, CEP 21941-590, RJ, Brazil
| | - Marcos H. Pereira
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Università di Padova, Padova, Italy
- Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, Minas Gerais, Brazil
| | | | - Amanda S. Souza
- Instituto de Nutrição, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Brazil
| | - Mário A. C. Silva-Neto
- Instituto de Bioquímica Médica, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, PO Box 68041, Cidade Universitária, Ilha do Fundão, Av. Bauhínia 400, Rio de Janeiro, CEP 21941-590, RJ, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Università di Padova, Padova, Italy
| | - Cesare Montecucco
- Dipartimento di Scienze Biomediche, Università di Padova, Padova, Italy
| | - Georgia C. Atella
- Instituto de Bioquímica Médica, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, PO Box 68041, Cidade Universitária, Ilha do Fundão, Av. Bauhínia 400, Rio de Janeiro, CEP 21941-590, RJ, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Università di Padova, Padova, Italy
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48
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Salinas S, Schiavo G, Kremer EJ. A hitchhiker's guide to the nervous system: the complex journey of viruses and toxins. Nat Rev Microbiol 2010; 8:645-55. [PMID: 20706281 DOI: 10.1038/nrmicro2395] [Citation(s) in RCA: 130] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To reach the central nervous system (CNS), pathogens have to circumvent the wall of tightly sealed endothelial cells that compose the blood-brain barrier. Neuronal projections that connect to peripheral cells and organs are the Achilles heels in CNS isolation. Some viruses and bacterial toxins interact with membrane receptors that are present at nerve terminals to enter the axoplasm. Pathogens can then be mistaken for cargo and recruit trafficking components, allowing them to undergo long-range axonal transport to neuronal cell bodies. In this Review, we highlight the strategies used by pathogens to exploit axonal transport during CNS invasion.
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Affiliation(s)
- Sara Salinas
- Institut de Génétique Moléculaire de Montpellier, CNRS UMR 5535, 34293 Montpellier Cedex 5, France.
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49
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Popoff MR, Poulain B. Bacterial toxins and the nervous system: neurotoxins and multipotential toxins interacting with neuronal cells. Toxins (Basel) 2010; 2:683-737. [PMID: 22069606 PMCID: PMC3153206 DOI: 10.3390/toxins2040683] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2010] [Revised: 03/18/2010] [Accepted: 04/07/2010] [Indexed: 12/13/2022] Open
Abstract
Toxins are potent molecules used by various bacteria to interact with a host organism. Some of them specifically act on neuronal cells (clostridial neurotoxins) leading to characteristics neurological affections. But many other toxins are multifunctional and recognize a wider range of cell types including neuronal cells. Various enterotoxins interact with the enteric nervous system, for example by stimulating afferent neurons or inducing neurotransmitter release from enterochromaffin cells which result either in vomiting, in amplification of the diarrhea, or in intestinal inflammation process. Other toxins can pass the blood brain barrier and directly act on specific neurons.
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Affiliation(s)
- Michel R. Popoff
- Neurotransmission et Sécrétion Neuroendocrine, CNRS UPR 2356 IFR 37 - Neurosciences, Centre de Neurochimie, 5, rue Blaise Pascal, F-67084 STRASBOURG cedex, France;
- Author to whom correspondence should be addressed;
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50
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Filler AG, Whiteside GT, Bacon M, Frederickson M, Howe FA, Rabinowitz MD, Sokoloff AJ, Deacon TW, Abell C, Munglani R, Griffiths JR, Bell BA, Lever AML. Tri-partite complex for axonal transport drug delivery achieves pharmacological effect. BMC Neurosci 2010; 11:8. [PMID: 20085661 PMCID: PMC2837052 DOI: 10.1186/1471-2202-11-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Accepted: 01/20/2010] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Targeted delivery of pharmaceutical agents into selected populations of CNS (Central Nervous System) neurons is an extremely compelling goal. Currently, systemic methods are generally used for delivery of pain medications, anti-virals for treatment of dermatomal infections, anti-spasmodics, and neuroprotectants. Systemic side effects or undesirable effects on parts of the CNS that are not involved in the pathology limit efficacy and limit clinical utility for many classes of pharmaceuticals. Axonal transport from the periphery offers a possible selective route, but there has been little progress towards design of agents that can accomplish targeted delivery via this intraneural route. To achieve this goal, we developed a tripartite molecular construction concept involving an axonal transport facilitator molecule, a polymer linker, and a large number of drug molecules conjugated to the linker, then sought to evaluate its neurobiology and pharmacological behavior. RESULTS We developed chemical synthesis methodologies for assembling these tripartite complexes using a variety of axonal transport facilitators including nerve growth factor, wheat germ agglutinin, and synthetic facilitators derived from phage display work. Loading of up to 100 drug molecules per complex was achieved. Conjugation methods were used that allowed the drugs to be released in active form inside the cell body after transport. Intramuscular and intradermal injection proved effective for introducing pharmacologically effective doses into selected populations of CNS neurons. Pharmacological efficacy with gabapentin in a paw withdrawal latency model revealed a ten fold increase in half life and a 300 fold decrease in necessary dose relative to systemic administration for gabapentin when the drug was delivered by axonal transport using the tripartite vehicle. CONCLUSION Specific targeting of selected subpopulations of CNS neurons for drug delivery by axonal transport holds great promise. The data shown here provide a basic framework for the intraneural pharmacology of this tripartite complex. The pharmacologically efficacious drug delivery demonstrated here verify the fundamental feasibility of using axonal transport for targeted drug delivery.
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Affiliation(s)
- Aaron G Filler
- Institute for Nerve Medicine, 2716 Ocean Park Blvd., Suite 3082, Santa Monica, CA, 90405, USA
- Department of Cell and Molecular Biology, St. George's Hospital Medical School, University of London, Cranmer Terrace, London, SW17 ORE, UK
- Department of Neurosurgery, Atkinson Morley's Hospital, St. George's, University of London, 31 Copse Hill Road, London SW20 ONE, UK
- Division of Neurosurgery, UCLA School of Medicine, Center for Health Sciences, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA
- SynGenix LTD, Babraham Hall, Babraham Research Campus, Cambridge, CB22 3AT, UK
- Molecular Synthetics LTD, Babraham Hall, Babraham Research Campus, Cambridge, CB22 3AT, UK
- Department of Organismic & Evolutionary Biology, Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, MA, 02138, USA
- Department of Anthropology, Human Evolutionary Biology, Peabody Museum, Harvard University, 11 Divinity Ave., Cambridge, MA, 02138, USA
| | - Garth T Whiteside
- SynGenix LTD, Babraham Hall, Babraham Research Campus, Cambridge, CB22 3AT, UK
- Wyeth Research, Neuroscience Discovery Research, CN 8000 Princeton, NJ, 08543, USA
| | - Mark Bacon
- SynGenix LTD, Babraham Hall, Babraham Research Campus, Cambridge, CB22 3AT, UK
- Molecular Synthetics LTD, Babraham Hall, Babraham Research Campus, Cambridge, CB22 3AT, UK
- Spinal Research, Station Road, Bramley, Guildford, Surrey, GU5 0AZ, UK
| | - Martyn Frederickson
- SynGenix LTD, Babraham Hall, Babraham Research Campus, Cambridge, CB22 3AT, UK
- Astex Therapeutics, 436 Cambridge Science Park, Milton Road, Cambridge, CB4 0QA, UK
- Department of Chemistry, University Chemical Laboratory, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Franklyn A Howe
- Department of Cell and Molecular Biology, St. George's Hospital Medical School, University of London, Cranmer Terrace, London, SW17 ORE, UK
| | - Miri D Rabinowitz
- Carmell Therapeutics Corporation, 10 South Tower, 320 E. North Ave., Pittsburgh, PA 15212, USA
- Department of Anthropology, Human Evolutionary Biology, Peabody Museum, Harvard University, 11 Divinity Ave., Cambridge, MA, 02138, USA
| | - Alan J Sokoloff
- Department of Physiology, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322, USA
- Department of Anthropology, Human Evolutionary Biology, Peabody Museum, Harvard University, 11 Divinity Ave., Cambridge, MA, 02138, USA
| | - Terrence W Deacon
- Department of Anthropology, Human Evolutionary Biology, Peabody Museum, Harvard University, 11 Divinity Ave., Cambridge, MA, 02138, USA
- Department of Anthropology, University of California at Berkeley, 232 Kroeber Hall, Berkeley, CA 94720, USA
| | - Chris Abell
- Department of Chemistry, University Chemical Laboratory, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Raj Munglani
- Department of Anesthesia, Addenbrooke's Hospital, University of Cambridge, Hills Road, Cambridge, CB2 2QQ, UK
| | - John R Griffiths
- Department of Cell and Molecular Biology, St. George's Hospital Medical School, University of London, Cranmer Terrace, London, SW17 ORE, UK
- Molecular Imaging, Cancer Research UK Cambridge Research Institute, Robinson Way, Cambridge, CB2 ORE, UK
| | - B Anthony Bell
- Department of Neurosurgery, Atkinson Morley's Hospital, St. George's, University of London, 31 Copse Hill Road, London SW20 ONE, UK
- Neuroscience Unit, St. George's University of London, Cranmer Terrace, London, SW17 ORE, UK
| | - Andrew ML Lever
- SynGenix LTD, Babraham Hall, Babraham Research Campus, Cambridge, CB22 3AT, UK
- Department of Internal Medicine, Addenbrooke's Hospital, University of Cambridge, Hills Road, Cambridge, CB2 2QQ, UK
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