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El-Wahsh S, Fraser C, Vucic S, Reddel S. Neuromuscular junction disorders: mimics and chameleons. Pract Neurol 2024:pn-2024-004148. [PMID: 39174301 DOI: 10.1136/pn-2024-004148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/07/2024] [Indexed: 08/24/2024]
Abstract
Neuromuscular junction (NMJ) disorders represent a heterogenous group of acquired and congenital disorders that present in variable and distinctive ways. The diagnosis is typically reached through a combination of clinical, serological, pharmacological and electrophysiological evaluation. While the diagnosis can be fairly straightforward in some cases, the overlap with other neurological disorders can make diagnosis challenging, particularly in pure ocular presentations and in seronegative patients. The over-reliance on serological tests and electrophysiological evaluation in isolation can lead to misdiagnosis. In this article, we provide an overview of the NMJ disorders, discuss red flags for the key differential diagnoses (mimics) and report the atypical ways in which NMJ disorders may present (chameleons).
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Affiliation(s)
- Shadi El-Wahsh
- Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
- Neurology Department, Concord Hospital, Concord, New South Wales, Australia
| | - Clare Fraser
- Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
- Save Sight Institute, The University of Sydney, Sydney, New South Wales, Australia
| | - Steve Vucic
- Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
- Neurology Department, Concord Hospital, Concord, New South Wales, Australia
| | - Stephen Reddel
- Neurology Department, Concord Hospital, Concord, New South Wales, Australia
- Brain and Mind Centre, The University of Sydney, Camperdown, New South Wales, Australia
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2
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Leka O, Wu Y, Zanetti G, Furler S, Reinberg T, Marinho J, Schaefer JV, Plückthun A, Li X, Pirazzini M, Kammerer RA. A DARPin promotes faster onset of botulinum neurotoxin A1 action. Nat Commun 2023; 14:8317. [PMID: 38110403 PMCID: PMC10728214 DOI: 10.1038/s41467-023-44102-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 11/30/2023] [Indexed: 12/20/2023] Open
Abstract
In this study, we characterize Designed Ankyrin Repeat Proteins (DARPins) as investigative tools to probe botulinum neurotoxin A1 (BoNT/A1) structure and function. We identify DARPin-F5 that completely blocks SNAP25 substrate cleavage by BoNT/A1 in vitro. X-ray crystallography reveals that DARPin-F5 inhibits BoNT/A1 activity by interacting with a substrate-binding region between the α- and β-exosite. This DARPin does not block substrate cleavage of BoNT/A3, indicating that DARPin-F5 is a subtype-specific inhibitor. BoNT/A1 Glu-171 plays a critical role in the interaction with DARPin-F5 and its mutation to Asp, the residue found in BoNT/A3, results in a loss of inhibition of substrate cleavage. In contrast to the in vitro results, DARPin-F5 promotes faster substrate cleavage of BoNT/A1 in primary neurons and muscle tissue by increasing toxin translocation. Our findings could have important implications for the application of BoNT/A1 in therapeutic areas requiring faster onset of toxin action combined with long persistence.
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Affiliation(s)
- Oneda Leka
- Laboratory of Biomolecular Research, Division of Biology, Paul Scherrer Institut, 5232, Villigen PSI, Switzerland
| | - Yufan Wu
- Laboratory of Biomolecular Research, Division of Biology, Paul Scherrer Institut, 5232, Villigen PSI, Switzerland
| | - Giulia Zanetti
- Department of Biomedical Sciences, University of Padova, 35121, Padova, Italy
| | - Sven Furler
- Department of Biochemistry, University of Zurich, 8057, Zurich, Switzerland
| | - Thomas Reinberg
- Department of Biochemistry, University of Zurich, 8057, Zurich, Switzerland
| | - Joana Marinho
- Department of Biochemistry, University of Zurich, 8057, Zurich, Switzerland
| | - Jonas V Schaefer
- Department of Biochemistry, University of Zurich, 8057, Zurich, Switzerland
| | - Andreas Plückthun
- Department of Biochemistry, University of Zurich, 8057, Zurich, Switzerland
| | - Xiaodan Li
- Laboratory of Biomolecular Research, Division of Biology, Paul Scherrer Institut, 5232, Villigen PSI, Switzerland
| | - Marco Pirazzini
- Department of Biomedical Sciences, University of Padova, 35121, Padova, Italy
| | - Richard A Kammerer
- Laboratory of Biomolecular Research, Division of Biology, Paul Scherrer Institut, 5232, Villigen PSI, Switzerland.
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Nowlan JP, Sies AN, Britney SR, Cameron ADS, Siah A, Lumsden JS, Russell S. Genomics of Tenacibaculum Species in British Columbia, Canada. Pathogens 2023; 12:pathogens12010101. [PMID: 36678448 PMCID: PMC9864904 DOI: 10.3390/pathogens12010101] [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: 12/02/2022] [Revised: 12/30/2022] [Accepted: 01/04/2023] [Indexed: 01/11/2023] Open
Abstract
Tenacibaculum is a genus of Gram-negative filamentous bacteria with a cosmopolitan distribution. The research describing Tenacibaculum genomes stems primarily from Norway and Chile due to their impacts on salmon aquaculture. Canadian salmon aquaculture also experiences mortality events related to the presence of Tenacibaculum spp., yet no Canadian Tenacibaculum genomes are publicly available. Ribosomal DNA sequencing of 16S and four species-specific 16S quantitative-PCR assays were used to select isolates cultured from Atlantic salmon with mouthrot in British Columbia (BC), Canada. Ten isolates representing four known and two unknown species of Tenacibaculum were selected for shotgun whole genome sequencing using the Oxford Nanopore's MinION platform. The genome assemblies achieved closed circular chromosomes for seven isolates and long contigs for the remaining three isolates. Average nucleotide identity analysis identified T. ovolyticum, T. maritimum, T. dicentrarchi, two genomovars of T. finnmarkense, and two proposed novel species T. pacificus sp. nov. type strain 18-2881-AT and T. retecalamus sp. nov. type strain 18-3228-7BT. Annotation in most of the isolates predicted putative virulence and antimicrobial resistance genes, most-notably toxins (i.e., hemolysins), type-IX secretion systems, and oxytetracycline resistance. Comparative analysis with the T. maritimum type-strain predicted additional toxins and numerous C-terminal secretion proteins, including an M12B family metalloprotease in the T. maritimum isolates from BC. The genomic prediction of virulence-associated genes provides important targets for studies of mouthrot disease, and the annotation of the antimicrobial resistance genes provides targets for surveillance and diagnosis in veterinary medicine.
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Affiliation(s)
- Joseph P. Nowlan
- Center for Innovation in Fish Health, Vancouver Island University, Nanaimo, BC V9R 5S5, Canada
- Department of Pathobiology, University of Guelph, Guelph, ON N1G 2W1, Canada
- Correspondence:
| | - Ashton N. Sies
- Department of Biology, University of Regina, Regina, SK S4S 0A2, Canada
- Institute for Microbial Systems and Society, Faculty of Science, University of Regina, Regina, SK S4S 0A2, Canada
| | - Scott R. Britney
- Center for Innovation in Fish Health, Vancouver Island University, Nanaimo, BC V9R 5S5, Canada
- Department of Pathobiology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Andrew D. S. Cameron
- Department of Biology, University of Regina, Regina, SK S4S 0A2, Canada
- Institute for Microbial Systems and Society, Faculty of Science, University of Regina, Regina, SK S4S 0A2, Canada
| | - Ahmed Siah
- BC Center for Aquatic Health Sciences, Campbell River, BC V9W 2C2, Canada
| | - John S. Lumsden
- Department of Pathobiology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Spencer Russell
- Center for Innovation in Fish Health, Vancouver Island University, Nanaimo, BC V9R 5S5, Canada
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4
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Negro S, Pirazzini M, Rigoni M. Models and methods to study Schwann cells. J Anat 2022; 241:1235-1258. [PMID: 34988978 PMCID: PMC9558160 DOI: 10.1111/joa.13606] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 11/26/2021] [Accepted: 11/29/2021] [Indexed: 12/22/2022] Open
Abstract
Schwann cells (SCs) are fundamental components of the peripheral nervous system (PNS) of all vertebrates and play essential roles in development, maintenance, function, and regeneration of peripheral nerves. There are distinct populations of SCs including: (1) myelinating SCs that ensheath axons by a specialized plasma membrane, called myelin, which enhances the conduction of electric impulses; (2) non-myelinating SCs, including Remak SCs, which wrap bundles of multiple axons of small caliber, and perysinaptic SCs (PSCs), associated with motor axon terminals at the neuromuscular junction (NMJ). All types of SCs contribute to PNS regeneration through striking morphological and functional changes in response to nerve injury, are affected in peripheral neuropathies and show abnormalities and a diminished plasticity during aging. Therefore, methodological approaches to study and manipulate SCs in physiological and pathophysiological conditions are crucial to expand the present knowledge on SC biology and to devise new therapeutic strategies to counteract neurodegenerative conditions and age-derived denervation. We present here an updated overview of traditional and emerging methodologies for the study of SCs for scientists approaching this research field.
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Affiliation(s)
- Samuele Negro
- Department of Biomedical SciencesUniversity of PaduaPaduaItaly
| | - Marco Pirazzini
- Department of Biomedical SciencesUniversity of PaduaPaduaItaly
- CIR‐MyoCentro Interdipartimentale di Ricerca di MiologiaUniversity of PaduaPadovaItaly
| | - Michela Rigoni
- Department of Biomedical SciencesUniversity of PaduaPaduaItaly
- CIR‐MyoCentro Interdipartimentale di Ricerca di MiologiaUniversity of PaduaPadovaItaly
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Fabris F, Šoštarić P, Matak I, Binz T, Toffan A, Simonato M, Montecucco C, Pirazzini M, Rossetto O. Detection of VAMP Proteolysis by Tetanus and Botulinum Neurotoxin Type B In Vivo with a Cleavage-Specific Antibody. Int J Mol Sci 2022; 23:ijms23084355. [PMID: 35457172 PMCID: PMC9024618 DOI: 10.3390/ijms23084355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 04/08/2022] [Accepted: 04/12/2022] [Indexed: 11/17/2022] Open
Abstract
Tetanus and Botulinum type B neurotoxins are bacterial metalloproteases that specifically cleave the vesicle-associated membrane protein VAMP at an identical peptide bond, resulting in inhibition of neuroexocytosis. The minute amounts of these neurotoxins commonly used in experimental animals are not detectable, nor is detection of their VAMP substrate sensitive enough. The immune detection of the cleaved substrate is much more sensitive, as we have previously shown for botulinum neurotoxin type A. Here, we describe the production in rabbit of a polyclonal antibody raised versus a peptide encompassing the 13 residues C-terminal with respect to the neurotoxin cleavage site. The antibody was affinity purified and found to recognize, with high specificity and selectivity, the novel N-terminus of VAMP that becomes exposed after cleavage by tetanus toxin and botulinum toxin type B. This antibody recognizes the neoepitope not only in native and denatured VAMP but also in cultured neurons and in neurons in vivo in neurotoxin-treated mice or rats, suggesting the great potential of this novel tool to elucidate tetanus and botulinum B toxin activity in vivo.
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Affiliation(s)
- Federico Fabris
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy; (F.F.); (C.M.)
| | - Petra Šoštarić
- Department of Pharmacology, School of Medicine, University of Zagreb, Šalata 11, 10000 Zagreb, Croatia; (P.Š.); (I.M.)
| | - Ivica Matak
- Department of Pharmacology, School of Medicine, University of Zagreb, Šalata 11, 10000 Zagreb, Croatia; (P.Š.); (I.M.)
| | - Thomas Binz
- Institute of Cellular Biochemistry, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany;
| | - Anna Toffan
- Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Università 10, 35020 Legnaro, Italy;
| | - Morena Simonato
- Institute of Neuroscience, Italian Research Council, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy;
| | - Cesare Montecucco
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy; (F.F.); (C.M.)
- Institute of Neuroscience, Italian Research Council, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy;
| | - Marco Pirazzini
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy; (F.F.); (C.M.)
- Interdepartmental Research Center of Myology CIR-Myo, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy
- Correspondence: (M.P.); (O.R.)
| | - Ornella Rossetto
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy; (F.F.); (C.M.)
- Institute of Neuroscience, Italian Research Council, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy;
- Interdepartmental Research Center of Myology CIR-Myo, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy
- Correspondence: (M.P.); (O.R.)
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Carré D, Martin V, Kouidri Y, Morin R, Norlund M, Gomes A, Lagarde JM, Lezmi S. The distribution of neuromuscular junctions depends on muscle pennation, when botulinum neurotoxin receptors and SNAREs expression are uniform in the rat. Toxicon 2022; 212:34-41. [DOI: 10.1016/j.toxicon.2022.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/12/2022] [Accepted: 04/05/2022] [Indexed: 11/25/2022]
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Latrotoxin-Induced Neuromuscular Junction Degeneration Reveals Urocortin 2 as a Critical Contributor to Motor Axon Terminal Regeneration. Int J Mol Sci 2022; 23:ijms23031186. [PMID: 35163106 PMCID: PMC8835473 DOI: 10.3390/ijms23031186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/18/2022] [Accepted: 01/20/2022] [Indexed: 11/24/2022] Open
Abstract
We used α-Latrotoxin (α-LTx), the main neurotoxic component of the black widow spider venom, which causes degeneration of the neuromuscular junction (NMJ) followed by a rapid and complete regeneration, as a molecular tool to identify by RNA transcriptomics factors contributing to the structural and functional recovery of the NMJ. We found that Urocortin 2 (UCN2), a neuropeptide involved in the stress response, is rapidly expressed at the NMJ after acute damage and that inhibition of CRHR2, the specific receptor of UCN2, delays neuromuscular transmission rescue. Experiments in neuronal cultures show that CRHR2 localises at the axonal tips of growing spinal motor neurons and that its expression inversely correlates with synaptic maturation. Moreover, exogenous UCN2 enhances the growth of axonal sprouts in cultured neurons in a CRHR2-dependent manner, pointing to a role of the UCN2-CRHR2 axis in the regulation of axonal growth and synaptogenesis. Consistently, exogenous administration of UCN2 strongly accelerates the regrowth of motor axon terminals degenerated by α-LTx, thereby contributing to the functional recovery of neuromuscular transmission after damage. Taken together, our results posit a novel role for UCN2 and CRHR2 as a signalling axis involved in NMJ regeneration.
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Sartori R, Hagg A, Zampieri S, Armani A, Winbanks CE, Viana LR, Haidar M, Watt KI, Qian H, Pezzini C, Zanganeh P, Turner BJ, Larsson A, Zanchettin G, Pierobon ES, Moletta L, Valmasoni M, Ponzoni A, Attar S, Da Dalt G, Sperti C, Kustermann M, Thomson RE, Larsson L, Loveland KL, Costelli P, Megighian A, Merigliano S, Penna F, Gregorevic P, Sandri M. Perturbed BMP signaling and denervation promote muscle wasting in cancer cachexia. Sci Transl Med 2021; 13:eaay9592. [PMID: 34349036 DOI: 10.1126/scitranslmed.aay9592] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 03/18/2021] [Indexed: 02/05/2023]
Abstract
Most patients with advanced solid cancers exhibit features of cachexia, a debilitating syndrome characterized by progressive loss of skeletal muscle mass and strength. Because the underlying mechanisms of this multifactorial syndrome are incompletely defined, effective therapeutics have yet to be developed. Here, we show that diminished bone morphogenetic protein (BMP) signaling is observed early in the onset of skeletal muscle wasting associated with cancer cachexia in mouse models and in patients with cancer. Cancer-mediated factors including Activin A and IL-6 trigger the expression of the BMP inhibitor Noggin in muscle, which blocks the actions of BMPs on muscle fibers and motor nerves, subsequently causing disruption of the neuromuscular junction (NMJ), denervation, and muscle wasting. Increasing BMP signaling in the muscles of tumor-bearing mice by gene delivery or pharmacological means can prevent muscle wasting and preserve measures of NMJ function. The data identify perturbed BMP signaling and denervation of muscle fibers as important pathogenic mechanisms of muscle wasting associated with tumor growth. Collectively, these findings present interventions that promote BMP-mediated signaling as an attractive strategy to counteract the loss of functional musculature in patients with cancer.
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Affiliation(s)
- Roberta Sartori
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
- Veneto Institute of Molecular Medicine, 35129 Padova, Italy
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Adam Hagg
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
- Centre for Muscle Research, Department of Anatomy and Physiology, University of Melbourne, Melbourne, VIC 3010, Australia
- Biomedicine Discovery Institute, Department of Physiology, Monash University, Melbourne, VIC 3800, Australia
| | - Sandra Zampieri
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
- Department of Surgery, Oncology and Gastroenterology, 3rd Surgical Clinic, University of Padova, 35128 Padua, Italy
- Myology Center, University of Padova, 35122 Padua, Italy
| | - Andrea Armani
- Veneto Institute of Molecular Medicine, 35129 Padova, Italy
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | | | - Laís R Viana
- Centre for Muscle Research, Department of Anatomy and Physiology, University of Melbourne, Melbourne, VIC 3010, Australia
- Department of Structural and Functional Biology, Biology Institute, University of Campinas, Campinas, São Paulo 13083-97, Brazil
| | - Mouna Haidar
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC 3052, Australia
| | - Kevin I Watt
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
- Centre for Muscle Research, Department of Anatomy and Physiology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Hongwei Qian
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
- Centre for Muscle Research, Department of Anatomy and Physiology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Camilla Pezzini
- Veneto Institute of Molecular Medicine, 35129 Padova, Italy
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Pardis Zanganeh
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC 3052, Australia
| | - Bradley J Turner
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC 3052, Australia
| | - Anna Larsson
- Theme Cancer, Karolinska University Hospital, Solna 171 76, Sweden
| | - Gianpietro Zanchettin
- Department of Surgery, Oncology and Gastroenterology, 3rd Surgical Clinic, University of Padova, 35128 Padua, Italy
| | - Elisa S Pierobon
- Department of Surgery, Oncology and Gastroenterology, 3rd Surgical Clinic, University of Padova, 35128 Padua, Italy
| | - Lucia Moletta
- Department of Surgery, Oncology and Gastroenterology, 3rd Surgical Clinic, University of Padova, 35128 Padua, Italy
| | - Michele Valmasoni
- Department of Surgery, Oncology and Gastroenterology, 3rd Surgical Clinic, University of Padova, 35128 Padua, Italy
| | - Alberto Ponzoni
- Department of Radiology, Padova General Hospital, 35121 Padova, Italy
| | - Shady Attar
- Department of Medicine, University Hospital of Padova, 35121 Padova, Italy
| | - Gianfranco Da Dalt
- Department of Surgery, Oncology and Gastroenterology, 3rd Surgical Clinic, University of Padova, 35128 Padua, Italy
| | - Cosimo Sperti
- Department of Surgery, Oncology and Gastroenterology, 3rd Surgical Clinic, University of Padova, 35128 Padua, Italy
| | - Monika Kustermann
- Center for Anatomy and Cell Biology, Medical University of Vienna, 1090 Vienna, Austria
| | - Rachel E Thomson
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
- Centre for Muscle Research, Department of Anatomy and Physiology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Lars Larsson
- Department of Physiology and Pharmacology, Karolinska Institutet, 171 77 Stockholm, Sweden
- Department of Clinical Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden
- Department of Biobehavioral Health, The Pennsylvania State University, University Park, PA 16802, USA
| | - Kate L Loveland
- Centre for Reproductive Health. Hudson Institute of Medical Research, Clayton, VIC 3168, Australia
- Department of Molecular and Translational Sciences, and Anatomy and Developmental Biology, Monash University, VIC 3800, Australia
| | - Paola Costelli
- Department of Clinical and Biological Sciences, University of Turin, 10125 Turin, Italy
| | - Aram Megighian
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Stefano Merigliano
- Department of Surgery, Oncology and Gastroenterology, 3rd Surgical Clinic, University of Padova, 35128 Padua, Italy
| | - Fabio Penna
- Department of Clinical and Biological Sciences, University of Turin, 10125 Turin, Italy
| | - Paul Gregorevic
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia.
- Centre for Muscle Research, Department of Anatomy and Physiology, University of Melbourne, Melbourne, VIC 3010, Australia
- Department of Biochemistry and Molecular Biology, Monash University, VIC 3800, Australia
- Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Marco Sandri
- Veneto Institute of Molecular Medicine, 35129 Padova, Italy.
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
- Myology Center, University of Padova, 35122 Padua, Italy
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada
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Cell-Based Reporter Release Assay to Determine the Activity of Calcium-Dependent Neurotoxins and Neuroactive Pharmaceuticals. Toxins (Basel) 2021; 13:toxins13040247. [PMID: 33808507 PMCID: PMC8066854 DOI: 10.3390/toxins13040247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 03/25/2021] [Accepted: 03/29/2021] [Indexed: 11/26/2022] Open
Abstract
The suitability of a newly developed cell-based functional assay was tested for the detection of the activity of a range of neurotoxins and neuroactive pharmaceuticals which act by stimulation or inhibition of calcium-dependent neurotransmitter release. In this functional assay, a reporter enzyme is released concomitantly with the neurotransmitter from neurosecretory vesicles. The current study showed that the release of a luciferase from a differentiated human neuroblastoma-based reporter cell line (SIMA-hPOMC1-26-GLuc cells) can be stimulated by a carbachol-mediated activation of the Gq-coupled muscarinic-acetylcholine receptor and by the Ca2+-channel forming spider toxin α-latrotoxin. Carbachol-stimulated luciferase release was completely inhibited by the muscarinic acetylcholine receptor antagonist atropine and α-latrotoxin-mediated release by the Ca2+-chelator EGTA, demonstrating the specificity of luciferase-release stimulation. SIMA-hPOMC1-26-GLuc cells express mainly L- and N-type and to a lesser extent T-type VGCC on the mRNA and protein level. In accordance with the expression profile a depolarization-stimulated luciferase release by a high K+-buffer was effectively and dose-dependently inhibited by L-type VGCC inhibitors and to a lesser extent by N-type and T-type inhibitors. P/Q- and R-type inhibitors did not affect the K+-stimulated luciferase release. In summary, the newly established cell-based assay may represent a versatile tool to analyze the biological efficiency of a range of neurotoxins and neuroactive pharmaceuticals which mediate their activity by the modulation of calcium-dependent neurotransmitter release.
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Lonati D, Schicchi A, Crevani M, Buscaglia E, Scaravaggi G, Maida F, Cirronis M, Petrolini VM, Locatelli CA. Foodborne Botulism: Clinical Diagnosis and Medical Treatment. Toxins (Basel) 2020; 12:toxins12080509. [PMID: 32784744 PMCID: PMC7472133 DOI: 10.3390/toxins12080509] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/04/2020] [Accepted: 08/06/2020] [Indexed: 12/14/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) produced by Clostridia species are the most potent identified natural toxins. Classically, the toxic neurological syndrome is characterized by an (afebrile) acute symmetric descending flaccid paralysis. The most know typical clinical syndrome of botulism refers to the foodborne form. All different forms are characterized by the same symptoms, caused by toxin-induced neuromuscular paralysis. The diagnosis of botulism is essentially clinical, as well as the decision to apply the specific antidotal treatment. The role of the laboratory is mandatory to confirm the clinical suspicion in relation to regulatory agencies, to identify the BoNTs involved and the source of intoxication. The laboratory diagnosis of foodborne botulism is based on the detection of BoNTs in clinical specimens/food samples and the isolation of BoNT from stools. Foodborne botulism intoxication is often underdiagnosed; the initial symptoms can be confused with more common clinical conditions (i.e., stroke, myasthenia gravis, Guillain–Barré syndrome—Miller–Fisher variant, Eaton–Lambert syndrome, tick paralysis and shellfish or tetrodotoxin poisoning). The treatment includes procedures for decontamination, antidote administration and, when required, support of respiratory function; few differences are related to the different way of exposure.
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Affiliation(s)
- Davide Lonati
- Correspondence: ; Tel.: +39-0382-26261; Fax: +39-0382-24605
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11
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Cornet S, Périer C, Kalinichev M. Optimization of the rat digit abduction score (DAS) assay: Evaluation of botulinum neurotoxin activity in the gastrocnemius lateralis, peronei, and extensor digitorum longus. Toxicon X 2020; 6:100029. [PMID: 32550584 PMCID: PMC7285904 DOI: 10.1016/j.toxcx.2020.100029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 02/07/2020] [Accepted: 02/11/2020] [Indexed: 11/24/2022] Open
Abstract
The mouse digit abduction score (DAS) assay is commonly used to measure muscle flaccidity-inducing effects of botulinum neurotoxin (BoNT) in vivo. Adapting the assay to rats has been challenging, as injection of onabotulinumtoxinA (onaBoNT-A) into the gastrocnemius muscle, as performed in mice, or into the tibialis anterior leads to sub-optimal sensitivity of the test (Broide et al., 2013). To optimize the experimental design of the rat DAS assay, we evaluated the effects of research-grade, purified, native BoNT serotype A1 (BoNT-A) in three muscles: the gastrocnemius lateralis, peronei, and extensor digitorum longus using female animals. Following injection, animals were tested daily for the digit abduction and body weight. BoNT-A caused dose-dependent inhibition of digit abduction when injected into the gastrocnemius lateralis or peronei. BoNT-A was six-fold more potent when injected into the peronei in comparison to the gastrocnemius lateralis. As injection of BoNT-A into the extensor digitorum longus muscle resulted in an all-or-none digit abduction response and therefore prevented calculation of the ED50, it was considered unsuitable for the rat DAS assay. At equipotent doses, peronei- and extensor digitorum longus-injected animals showed normal body weight gain, while those injected with BoNT-A into the gastrocnemius lateralis gained less weight in comparison to vehicle-treated controls. Thus, injecting the peronei muscles of female rats offers optimized conditions for evaluating the biological properties of BoNTs in the rat DAS assay; for assessing the potency, onset, and duration of action across natural and recombinant BoNT in a robust and reproducible manner. BoNT-A was tested in the DAS following injection into three muscles of female rats. DAS linked to the extensor digitorum longus injections lacks dose-dependency. Gastrocnemius injections inhibit digit abduction, but with an effect on body weigh. Peronei injections are linked to higher potency and no effects on body weight. Using the peronei in female rats are optimized conditions in the rat DAS assay.
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Affiliation(s)
- Sylvie Cornet
- Ipsen Innovation, 5, Avenue du Canada, 91940, Les Ulis, France
| | - Cindy Périer
- Ipsen Innovation, 5, Avenue du Canada, 91940, Les Ulis, France
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12
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Cornet S, Périer C, Kalinichev M. WITHDRAWN: Optimization of the rat digit abduction score (DAS) assay: Evaluation of botulinum neurotoxin activity in the gastrocnemius lateralis, peronei, and extensor digitorum longus. Toxicon 2020:S0041-0101(20)30045-3. [PMID: 32113789 DOI: 10.1016/j.toxicon.2020.02.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 02/07/2020] [Accepted: 02/11/2020] [Indexed: 10/25/2022]
Abstract
The Publisher regrets that this article is an accidental duplication of an article that has already been published, https://doi.org/10.1016/j.toxcx.2020.100029. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.
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Affiliation(s)
- Sylvie Cornet
- Ipsen Innovation. 5, Avenue du Canada, 91940 Les Ulis, France
| | - Cindy Périer
- Ipsen Innovation. 5, Avenue du Canada, 91940 Les Ulis, France
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13
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Williams MPI, Rigon M, Straka T, Hörner SJ, Thiel M, Gretz N, Hafner M, Reischl M, Rudolf R. A Novel Optical Tissue Clearing Protocol for Mouse Skeletal Muscle to Visualize Endplates in Their Tissue Context. Front Cell Neurosci 2019; 13:49. [PMID: 30873005 PMCID: PMC6401545 DOI: 10.3389/fncel.2019.00049] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 02/01/2019] [Indexed: 12/11/2022] Open
Abstract
Neuromuscular junctions (NMJs) mediate skeletal muscle contractions and play an important role in several neuromuscular disorders when their morphology and function are compromised. However, due to their small size and sparse distribution throughout the comparatively large, inherently opaque muscle tissue the analysis of NMJ morphology has been limited to teased fiber preparations, longitudinal muscle sections, and flat muscles. Consequently, whole mount analyses of NMJ morphology, numbers, their distribution, and assignment to a given muscle fiber have also been impossible to determine in muscle types that are frequently used in experimental paradigms. This impossibility is exacerbated by the lack of optical tissue clearing techniques that are compatible with clear and persistent NMJ stains. Here, we present MYOCLEAR, a novel and highly reproducible muscle tissue clearing protocol. Based on hydrogel-based tissue clearing methods, this protocol permits the labeling and detection of all NMJs in adult hindleg extensor digitorum longus muscles from wildtype and diseased mice. The method is also applicable to adult mouse diaphragm muscles and can be used for different staining agents, including toxins, lectins, antibodies, and nuclear dyes. It will be useful in understanding the distribution, morphological features, and muscle tissue context of NMJs in hindleg muscle whole mounts for biomedical and basic research.
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Affiliation(s)
| | - Matteo Rigon
- Institute of Molecular and Cell Biology, Mannheim University of Applied Sciences, Mannheim, Germany
| | - Tatjana Straka
- Institute of Molecular and Cell Biology, Mannheim University of Applied Sciences, Mannheim, Germany.,Interdisciplinary Center for Neurosciences, Heidelberg University, Heidelberg, Germany
| | - Sarah Janice Hörner
- Institute of Molecular and Cell Biology, Mannheim University of Applied Sciences, Mannheim, Germany.,Interdisciplinary Center for Neurosciences, Heidelberg University, Heidelberg, Germany
| | - Manfred Thiel
- Department of Anesthesiology and Surgical Intensive Care Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Norbert Gretz
- Medical Faculty Mannheim, Medical Research Center, Heidelberg University, Mannheim, Germany.,Medical Faculty Mannheim, Institute of Medical Technology, Mannheim University of Applied Sciences, Mannheim, Germany
| | - Mathias Hafner
- Institute of Molecular and Cell Biology, Mannheim University of Applied Sciences, Mannheim, Germany.,Medical Faculty Mannheim, Institute of Medical Technology, Mannheim University of Applied Sciences, Mannheim, Germany
| | - Markus Reischl
- Institute for Automation and Applied Informatics, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
| | - Rüdiger Rudolf
- Institute of Molecular and Cell Biology, Mannheim University of Applied Sciences, Mannheim, Germany.,Interdisciplinary Center for Neurosciences, Heidelberg University, Heidelberg, Germany.,Medical Faculty Mannheim, Institute of Medical Technology, Mannheim University of Applied Sciences, Mannheim, Germany.,Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
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14
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Neurobiology and therapeutic applications of neurotoxins targeting transmitter release. Pharmacol Ther 2019; 193:135-155. [DOI: 10.1016/j.pharmthera.2018.08.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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15
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Lin Z, Cheng Y, Wang RJ, Du J, Volovych O, Li JC, Hu Y, Lu ZY, Lu Z, Zou Z. A Metalloprotease Homolog Venom Protein From a Parasitoid Wasp Suppresses the Toll Pathway in Host Hemocytes. Front Immunol 2018; 9:2301. [PMID: 30405599 PMCID: PMC6206080 DOI: 10.3389/fimmu.2018.02301] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 09/17/2018] [Indexed: 12/18/2022] Open
Abstract
Parasitoid wasps depend on a variety of maternal virulence factors to ensure successful parasitism. Encapsulation response carried out by host hemocytes is one of the major host immune responses toward limiting endoparasitoid wasp offspring production. We found that VRF1, a metalloprotease homolog venom protein identified from the endoparasitoid wasp, Microplitis mediator, could modulate egg encapsulation in its host, the cotton bollworm, Helicoverpa armigera. Here, we show that the VRF1 proenzyme is cleaved after parasitism, and that the C-terminal fragment containing the catalytic domain enters host hemocytes 6 h post-parasitism. Furthermore, using yeast two-hybrid and pull-down assays, VRF1 is shown to interact with the H. armigera NF-κB factor, Dorsal. We also show that overexpressed of VRF1 in an H. armigera cell line cleaved Dorsal in vivo. Taken together, our results have revealed a novel mechanism by which a component of endoparasitoid wasp venom interferes with the Toll signaling pathway in the host hemocytes.
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Affiliation(s)
- Zhe Lin
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Yang Cheng
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Rui-Juan Wang
- Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, China
| | - Jie Du
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Olga Volovych
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Jian-Cheng Li
- Institute of Plant Protection of Hebei Academy of Agriculture and Forestry Sciences, Baoding, China
| | - Yang Hu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Zi-Yun Lu
- Institute of Plant Protection of Hebei Academy of Agriculture and Forestry Sciences, Baoding, China
| | - Zhiqiang Lu
- Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, China
| | - Zhen Zou
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
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16
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Zanetti G, Duregotti E, Locatelli CA, Giampreti A, Lonati D, Rossetto O, Pirazzini M. Variability in venom composition of European viper subspecies limits the cross-effectiveness of antivenoms. Sci Rep 2018; 8:9818. [PMID: 29959358 PMCID: PMC6026201 DOI: 10.1038/s41598-018-28135-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 06/14/2018] [Indexed: 12/17/2022] Open
Abstract
Medically relevant cases of snakebite in Europe are predominately caused by European vipers of the genus Vipera. Systemic envenoming by European vipers can cause severe pathology in humans and different clinical manifestations are associated with different members of this genus. The most representative vipers in Europe are V. aspis and V. berus and neurological symptoms have been reported in humans envenomed by the former but not by the latter species. In this study we determined the toxicological profile of V. aspis and V. berus venoms in vivo in mice and we tested the effectiveness of two antivenoms, commonly used as antidotes, in counteracting the specific activities of the two venoms. We found that V. aspis, but not V. berus, is neurotoxic and that this effect is due to the degeneration of peripheral nerve terminals at the NMJ and is not neutralized by the two tested antisera. Differently, V. berus causes a haemorrhagic effect, which is efficiently contrasted by the same antivenoms. These results indicate that the effectiveness of different antisera is strongly influenced by the variable composition of the venoms and reinforce the arguments supporting the use polyvalent antivenoms.
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Affiliation(s)
- Giulia Zanetti
- University of Padova, Department of Biomedical Sciences, Padova, 35131, Italy
| | - Elisa Duregotti
- University of Padova, Department of Biomedical Sciences, Padova, 35131, Italy
- King's College London, Department of Cardiology, James Black Centre, London, SE5 9NU, United Kingdom
| | - Carlo Alessandro Locatelli
- Istituti Clinici Scientifici Maugeri, IRCCS Maugeri Hospital and University of Pavia, Poison Control Centre and National Toxicology Information Centre - Toxicology Unit, Pavia, 27100, Italy
| | - Andrea Giampreti
- Istituti Clinici Scientifici Maugeri, IRCCS Maugeri Hospital and University of Pavia, Poison Control Centre and National Toxicology Information Centre - Toxicology Unit, Pavia, 27100, Italy
| | - Davide Lonati
- Istituti Clinici Scientifici Maugeri, IRCCS Maugeri Hospital and University of Pavia, Poison Control Centre and National Toxicology Information Centre - Toxicology Unit, Pavia, 27100, Italy
| | - Ornella Rossetto
- University of Padova, Department of Biomedical Sciences, Padova, 35131, Italy
| | - Marco Pirazzini
- University of Padova, Department of Biomedical Sciences, Padova, 35131, Italy.
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17
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Zanetti G, Negro S, Megighian A, Pirazzini M. Electrophysiological Recordings of Evoked End-Plate Potential on Murine Neuro-muscular Synapse Preparations. Bio Protoc 2018; 8:e2803. [PMID: 34286022 DOI: 10.21769/bioprotoc.2803] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 03/29/2018] [Accepted: 04/22/2018] [Indexed: 11/02/2022] Open
Abstract
Neuromuscular junction (NMJ) is the specialized chemical synapse that mediates the transmission of the electrical impulse running along motor neuron axons to skeletal muscle fibers. NMJ is the best characterized chemical synapse and its study along many years of research has provided most of the general knowledge of synapse development, structure and functionality. Electrophysiology is the most accurate experimental procedure to study NMJ physiology and it largely contributed to the elucidation of synaptic transmission basic principles. Many electrophysiological techniques have been developed to study NMJ physiology and physiopathology. In this paper, we describe an ex vivo tissue preparation for electrophysiology that can be applied to investigate nerve-muscle transmission functionality in mice. It is routinely used in our laboratory to study presynaptic neurotoxins, antitoxins, and to monitor NMJ degeneration and regeneration. This is a broadly applicable technique which can also be adopted to investigate alterations of NMJ activity in mouse models of neuromuscular diseases, including peripheral neuropathies, motor neuron disorders and myasthenic syndromes.
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Affiliation(s)
- Giulia Zanetti
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Samuele Negro
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Aram Megighian
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Marco Pirazzini
- Department of Biomedical Sciences, University of Padova, Padova, Italy
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18
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Pellett S, Bradshaw M, Tepp WH, Pier CL, Whitemarsh RCM, Chen C, Barbieri JT, Johnson EA. The Light Chain Defines the Duration of Action of Botulinum Toxin Serotype A Subtypes. mBio 2018; 9:e00089-18. [PMID: 29588398 PMCID: PMC5874905 DOI: 10.1128/mbio.00089-18] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 02/20/2018] [Indexed: 12/26/2022] Open
Abstract
Botulinum neurotoxin (BoNT) is the causative agent of botulism and a widely used pharmaceutical to treat a variety of neurological diseases. BoNTs are 150-kDa protein toxins organized into heavy chain (HC) and light chain (LC) domains linked by a disulfide bond. The HC selectively binds to neurons and aids cell entry of the enzymatically active LC. There are seven immunological BoNT serotypes (A to G); each serotype includes genetic variants, termed subtypes. Only two subtypes, BoNT/A1 and BoNT/B1, are currently used as therapeutics. BoNT serotype A (BoNT/A) subtypes A2 to A8 show distinct potency, duration of action, and pathology relative to BoNT/A1. Specifically, BoNT/A3 possesses shorter duration of action and elicits distinct symptoms in mice at high toxin doses. In this report, we analyzed the roles of LC and HC of BoNT/A3 for duration of action, neuronal cell entry, and mouse pathology by using clostridium-derived recombinant hybrid BoNTs consisting of reciprocal LC and HC (BoNTA1/A3 and BoNTA3/A1). Hybrid toxins were processed in their expression host to a dichain BoNT consisting of LC and HC linked via a disulfide bond. The LC and HC defined BoNT potency in mice and BoNT toxicity for cultured neuronal cells, while the LC defined the duration of BoNT action in cell and mouse models. Protein alignment identified a previously unrecognized region within the LC subtype A3 (LC/A3) relative to the other LC serotype A (LC/A) subtypes (low primary acid homology [LPH]) that correlated to intracellular LC localization. This study shows the utility of recombinant hybrid BoNTs with new therapeutic potential, while remaining sensitive to antitoxins and therapies to native BoNT.IMPORTANCE Botulinum neurotoxins are the most potent protein toxins for humans and potential bioterrorism threats, but they are also widely used as pharmaceuticals. Within the large family of BoNTs, only two subtypes are currently used as pharmaceuticals, with a large number of BoNT subtypes remaining as untapped potential sources for unique pharmaceuticals. Here, two recombinant hybrid toxins were engineered, consisting of domains from two BoNT subtypes that possess distinct duration of action and activity in human neurons and mice. We define the functional domains responsible for BoNT action and demonstrate creation of functional hybrid BoNTs with new therapeutic potential, while remaining sensitive to antitoxins and therapies to native BoNT.
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Affiliation(s)
- Sabine Pellett
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA
| | - Marite Bradshaw
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA
| | - William H Tepp
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA
| | - Christina L Pier
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA
| | | | - Chen Chen
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Joseph T Barbieri
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Eric A Johnson
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA
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19
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Neurophysiological Measures of Efficacy and Safety for Botulinum Toxin Injection in Facial and Bulbar Muscles: Special Considerations. Toxins (Basel) 2017; 9:toxins9110352. [PMID: 29084148 PMCID: PMC5705967 DOI: 10.3390/toxins9110352] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 10/16/2017] [Accepted: 10/27/2017] [Indexed: 12/27/2022] Open
Abstract
Botulinum toxin (BoNT) injections into facial and bulbar muscles are widely and increasingly used as medical treatments for cervical and facial dystonia, facial hemispasm, correction of facial palsy, hyperhidrosis, as well as cosmetic treatment of glabellar lines associated with grief and anger. Although BoNT treatment is generally considered safe, the diffusion of the toxin to surrounding muscles may result in complications, including difficulties swallowing, in a dose-dependent manner. The sensitivity of clinical examination for detecting adverse events after BoNT treatment is limited. Few reports have highlighted the potential effects on other muscles in the facial area due to the spreading of the toxin. The possibilities of spreading and thus unknown pharmacological BoNT effects in non-targeted muscles emphasise the importance of correct administration of BoNT in terms of dose selection, injection points, and appropriate effect surveillance. In this review article, we will focus on novel objective measures of efficacy and safety regarding BoNT treatment of facial muscles and the reasons why this is important.
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20
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Zanetti G, Sikorra S, Rummel A, Krez N, Duregotti E, Negro S, Henke T, Rossetto O, Binz T, Pirazzini M. Botulinum neurotoxin C mutants reveal different effects of syntaxin or SNAP-25 proteolysis on neuromuscular transmission. PLoS Pathog 2017; 13:e1006567. [PMID: 28800600 PMCID: PMC5568444 DOI: 10.1371/journal.ppat.1006567] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 08/23/2017] [Accepted: 08/03/2017] [Indexed: 11/30/2022] Open
Abstract
Botulinum neurotoxin serotype C (BoNT/C) is a neuroparalytic toxin associated with outbreaks of animal botulism, particularly in birds, and is the only BoNT known to cleave two different SNARE proteins, SNAP-25 and syntaxin. BoNT/C was shown to be a good substitute for BoNT/A1 in human dystonia therapy because of its long lasting effects and absence of neuromuscular damage. Two triple mutants of BoNT/C, namely BoNT/C S51T/R52N/N53P (BoNT/C α-51) and BoNT/C L200W/M221W/I226W (BoNT/C α-3W), were recently reported to selectively cleave syntaxin and have been used here to evaluate the individual contribution of SNAP-25 and syntaxin cleavage to the effect of BoNT/C in vivo. Although BoNT/C α-51 and BoNT/C α-3W toxins cleave syntaxin with similar efficiency, we unexpectedly found also cleavage of SNAP-25, although to a lesser extent than wild type BoNT/C. Interestingly, the BoNT/C mutants exhibit reduced lethality compared to wild type toxin, a result that correlated with their residual activity against SNAP-25. In spite of this, a local injection of BoNT/C α-51 persistently impairs neuromuscular junction activity. This is due to an initial phase in which SNAP-25 cleavage causes a complete blockade of neurotransmission, and to a second phase of incomplete impairment ascribable to syntaxin cleavage. Together, these results indicate that neuroparalysis of BoNT/C at the neuromuscular junction is due to SNAP-25 cleavage, while the proteolysis of syntaxin provides a substantial, but incomplete, neuromuscular impairment. In light of this evidence, we discuss a possible clinical use of BoNT/C α-51 as a botulinum neurotoxin endowed with a wide safety margin and a long lasting effect. The seven established Botulinum Neurotoxins serotypes (BoNT/A to G) and the many BoNT subtypes, the causative agents of botulism, are the most poisonous substances known (lethal doses in the low ng/kg range). Due to their toxicological properties, BoNTs are Janus-faced toxins: potent pathogenic factors and potential bioterrorism agents as well as safe and efficacious therapeutics. BoNTs exert their neuroparalytic action by cleaving SNARE proteins, either SNAP-25 or synaptobrevin/VAMP, which mediate neurotransmitter release at the neuromuscular junction; BoNT/C is the only serotype shown to cleave SNAP-25 and syntaxin-1 in vitro. Our study shows for the first time that this parallel cleavage also occurs in vivo. By using mutated toxins reported to be syntaxin-selective, we found that SNAP-25 proteolysis at the neuromuscular junction is the key determinant of BoNT/C lethality as it completely blocks nerve-muscle transmission. Conversely, syntaxin-1 cleavage only attenuates nerve terminal activity without inactivating the synapse, leading to only a partial decrease of neuromuscular functionality. As a result, the BoNT/C mutants have dramatically reduced lethality, but still modulate neuromuscular junction activity upon intramuscular injection. This aspect is particularly relevant considering the possible use of syntaxin-specific BoNT/C derivatives to improve the present clinical utilization of BoNTs.
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Affiliation(s)
- Giulia Zanetti
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Stefan Sikorra
- Institut für Zellbiochemie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Andreas Rummel
- Institut für Toxikologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Nadja Krez
- Institut für Toxikologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Elisa Duregotti
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Samuele Negro
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Tina Henke
- Institut für Zellbiochemie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Ornella Rossetto
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Thomas Binz
- Institut für Zellbiochemie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Marco Pirazzini
- Department of Biomedical Sciences, University of Padova, Padova, Italy
- * E-mail:
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21
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Deubiquitinating enzyme VCIP135 dictates the duration of botulinum neurotoxin type A intoxication. Proc Natl Acad Sci U S A 2017; 114:E5158-E5166. [PMID: 28584101 DOI: 10.1073/pnas.1621076114] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Botulism is characterized by flaccid paralysis, which can be caused by intoxication with any of the seven known serotypes of botulinum neurotoxin (BoNT), all of which disrupt synaptic transmission by endoproteolytic cleavage of SNARE proteins. BoNT serotype A (BoNT/A) has the most prolonged or persistent effects, which can last several months, and exerts its effects by specifically cleaving and inactivating SNAP25. A major factor contributing to the persistence of intoxication is the long half-life of the catalytic light chain, which remains enzymatically active months after entry into cells. Here we report that BoNT/A catalytic light chain binds to, and is a substrate for, the ubiquitin ligase HECTD2. However, the light chain evades proteasomal degradation by the dominant effect of a deubiquitinating enzyme, VCIP135/VCPIP1. This deubiquitinating enzyme binds BoNT/A light chain directly, with the two associating in cells through the C-terminal 77 amino acids of the light chain protease. The development of specific DUB inhibitors, together with inhibitors of BoNT/A proteolytic activity, may be useful for reducing the morbidity and public health costs associated with BoNT/A intoxication and could have potential biodefense implications.
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