title: Thioredoxin and its reductase are present on synaptic vesicles, and their inhibition prevents the paralysis induced by botulinum neurotoxins.
abstract: Botulinum neurotoxins consist of a metalloprotease linked via a conserved interchain disulfide bond to a heavy chain responsible for neurospecific binding and translocation of the enzymatic domain in the nerve terminal cytosol. The metalloprotease activity is enabled upon disulfide reduction and causes neuroparalysis by cleaving the SNARE proteins. Here, we show that the thioredoxin reductase-thioredoxin protein disulfide-reducing system is present on synaptic vesicles and that it is functional and responsible for the reduction of the interchain disulfide of botulinum neurotoxin serotypes A, C, and E. Specific inhibitors of thioredoxin reductase or thioredoxin prevent intoxication of cultured neurons in a dose-dependent manner and are also very effective inhibitors of the paralysis of the neuromuscular junction. We found that this group of inhibitors of botulinum neurotoxins is very effective in vivo. Most of them are nontoxic and are good candidates as preventive and therapeutic drugs for human botulism.
authors.affiliation: Department of Biomedical Sciences and National Research Council Institute of Neuroscience, University of Padova, Via Ugo Bassi 58/B, 35121 Padova, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Pirazzini
authors.affiliation: Department of Biomedical Sciences and National Research Council Institute of Neuroscience, University of Padova, Via Ugo Bassi 58/B, 35121 Padova, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Azarnia Tehran
authors.affiliation: Department of Biomedical Sciences and National Research Council Institute of Neuroscience, University of Padova, Via Ugo Bassi 58/B, 35121 Padova, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Zanetti
authors.affiliation: Department of Biomedical Sciences and National Research Council Institute of Neuroscience, University of Padova, Via Ugo Bassi 58/B, 35121 Padova, Italy.
authors.forename: Aram
authors.initials: A
authors.lastname: Megighian
authors.affiliation: Department of Biomedical Sciences and National Research Council Institute of Neuroscience, University of Padova, Via Ugo Bassi 58/B, 35121 Padova, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Scorzeto
authors.affiliation: Histology and Molecular Biology Section, Army Medical and Veterinary Research Center, Via Santo Stefano Rotondo 4, 00184 Rome, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Fillo
authors.affiliation: Public Health England, Porton Down, Salisbury, Wiltshire SP4 OJG, UK.
authors.forename: Clifford C
authors.initials: CC
authors.lastname: Shone
authors.affiliation: Institut für Biochemie, Medizinische Hochschule Hannover, 30623 Hannover, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Binz
authors.affiliation: Department of Biomedical Sciences and National Research Council Institute of Neuroscience, University of Padova, Via Ugo Bassi 58/B, 35121 Padova, Italy.
authors.forename: Ornella
authors.initials: O
authors.lastname: Rossetto
authors.affiliation: Histology and Molecular Biology Section, Army Medical and Veterinary Research Center, Via Santo Stefano Rotondo 4, 00184 Rome, Italy.
authors.forename: Florigio
authors.initials: F
authors.lastname: Lista
authors.affiliation: Department of Biomedical Sciences and National Research Council Institute of Neuroscience, University of Padova, Via Ugo Bassi 58/B, 35121 Padova, Italy. Electronic address: cesare.montecucco@gmail.com.
authors.forename: Cesare
authors.initials: C
authors.lastname: Montecucco
mesh_terms: D000818:Animals; D001905:Botulinum Toxins / Q000633:toxicity*; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D003474:Curcumin / Q000494:pharmacology / Q000627:therapeutic use; D003593:Cytoplasm / Q000378:metabolism; D004220:Disulfides / Q000494:pharmacology / Q000627:therapeutic use; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D007093:Imidazoles / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D051379:Mice; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D010243:Paralysis / Q000209:etiology / Q000517:prevention & control*; D012703:Serotyping; D013572:Synaptic Vesicles / Q000187:drug effects* / Q000201:enzymology*; D050825:Synaptosomal-Associated Protein 25 / Q000378:metabolism; D013880:Thioredoxin-Disulfide Reductase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013879:Thioredoxins / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D004220:Disulfides; D004791:Enzyme Inhibitors; D007093:Imidazoles; D050825:Synaptosomal-Associated Protein 25; D013879:Thioredoxins; C412893:1-methylpropyl-2-imidazolyl disulfide; D013880:Thioredoxin-Disulfide Reductase; D001905:Botulinum Toxins; D003474:Curcumin