Facial neuromuscular junctions and brainstem nuclei are the target of tetanus neurotoxin in cephalic tetanus

Cephalic tetanus (CT) is a severe form of tetanus that follows head wounds and the intoxication of cranial nerves by tetanus neurotoxin (TeNT). Hallmarks of CT are cerebral palsy, which anticipates the spastic paralysis of tetanus, and rapid evolution of cardiorespiratory deficit even without genera...

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Main Authors: Federico Fabris, Stefano Varani, Marika Tonellato, Ivica Matak, Petra Šoštarić, Patrik Meglić, Matteo Caleo, Aram Megighian, Ornella Rossetto, Cesare Montecucco, Marco Pirazzini
Format: Article
Language:English
Published: American Society for Clinical investigation 2023-06-01
Series:JCI Insight
Subjects:
Online Access:https://doi.org/10.1172/jci.insight.166978
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author Federico Fabris
Stefano Varani
Marika Tonellato
Ivica Matak
Petra Šoštarić
Patrik Meglić
Matteo Caleo
Aram Megighian
Ornella Rossetto
Cesare Montecucco
Marco Pirazzini
author_facet Federico Fabris
Stefano Varani
Marika Tonellato
Ivica Matak
Petra Šoštarić
Patrik Meglić
Matteo Caleo
Aram Megighian
Ornella Rossetto
Cesare Montecucco
Marco Pirazzini
author_sort Federico Fabris
collection DOAJ
description Cephalic tetanus (CT) is a severe form of tetanus that follows head wounds and the intoxication of cranial nerves by tetanus neurotoxin (TeNT). Hallmarks of CT are cerebral palsy, which anticipates the spastic paralysis of tetanus, and rapid evolution of cardiorespiratory deficit even without generalized tetanus. How TeNT causes this unexpected flaccid paralysis, and how the canonical spasticity then rapidly evolves into cardiorespiratory defects, remain unresolved aspects of CT pathophysiology. Using electrophysiology and immunohistochemistry, we demonstrate that TeNT cleaves its substrate vesicle-associated membrane protein within facial neuromuscular junctions and causes a botulism-like paralysis overshadowing tetanus spasticity. Meanwhile, TeNT spreads among brainstem neuronal nuclei and, as shown by an assay measuring the ventilation ability of CT mice, harms essential functions like respiration. A partial axotomy of the facial nerve revealed a potentially new ability of TeNT to undergo intra-brainstem diffusion, which allows the toxin to spread to brainstem nuclei devoid of direct peripheral efferents. This mechanism is likely to be involved in the transition from local to generalized tetanus. Overall, the present findings suggest that patients with idiopathic facial nerve palsy should be immediately considered for CT and treated with antisera to block the potential progression to a life-threatening form of tetanus.
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spelling doaj.art-395ac61e128f4db1a549005bf07389652023-11-07T16:25:42ZengAmerican Society for Clinical investigationJCI Insight2379-37082023-06-01811Facial neuromuscular junctions and brainstem nuclei are the target of tetanus neurotoxin in cephalic tetanusFederico FabrisStefano VaraniMarika TonellatoIvica MatakPetra ŠoštarićPatrik MeglićMatteo CaleoAram MegighianOrnella RossettoCesare MontecuccoMarco PirazziniCephalic tetanus (CT) is a severe form of tetanus that follows head wounds and the intoxication of cranial nerves by tetanus neurotoxin (TeNT). Hallmarks of CT are cerebral palsy, which anticipates the spastic paralysis of tetanus, and rapid evolution of cardiorespiratory deficit even without generalized tetanus. How TeNT causes this unexpected flaccid paralysis, and how the canonical spasticity then rapidly evolves into cardiorespiratory defects, remain unresolved aspects of CT pathophysiology. Using electrophysiology and immunohistochemistry, we demonstrate that TeNT cleaves its substrate vesicle-associated membrane protein within facial neuromuscular junctions and causes a botulism-like paralysis overshadowing tetanus spasticity. Meanwhile, TeNT spreads among brainstem neuronal nuclei and, as shown by an assay measuring the ventilation ability of CT mice, harms essential functions like respiration. A partial axotomy of the facial nerve revealed a potentially new ability of TeNT to undergo intra-brainstem diffusion, which allows the toxin to spread to brainstem nuclei devoid of direct peripheral efferents. This mechanism is likely to be involved in the transition from local to generalized tetanus. Overall, the present findings suggest that patients with idiopathic facial nerve palsy should be immediately considered for CT and treated with antisera to block the potential progression to a life-threatening form of tetanus.https://doi.org/10.1172/jci.insight.166978Neuroscience
spellingShingle Federico Fabris
Stefano Varani
Marika Tonellato
Ivica Matak
Petra Šoštarić
Patrik Meglić
Matteo Caleo
Aram Megighian
Ornella Rossetto
Cesare Montecucco
Marco Pirazzini
Facial neuromuscular junctions and brainstem nuclei are the target of tetanus neurotoxin in cephalic tetanus
JCI Insight
Neuroscience
title Facial neuromuscular junctions and brainstem nuclei are the target of tetanus neurotoxin in cephalic tetanus
title_full Facial neuromuscular junctions and brainstem nuclei are the target of tetanus neurotoxin in cephalic tetanus
title_fullStr Facial neuromuscular junctions and brainstem nuclei are the target of tetanus neurotoxin in cephalic tetanus
title_full_unstemmed Facial neuromuscular junctions and brainstem nuclei are the target of tetanus neurotoxin in cephalic tetanus
title_short Facial neuromuscular junctions and brainstem nuclei are the target of tetanus neurotoxin in cephalic tetanus
title_sort facial neuromuscular junctions and brainstem nuclei are the target of tetanus neurotoxin in cephalic tetanus
topic Neuroscience
url https://doi.org/10.1172/jci.insight.166978
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