Multiple forms of SNARE complexes in exocytosis from chromaffin cells: effects of Ca2+, MgATP and botulinum toxin type A

2002 ◽  
Vol 115 (3) ◽  
pp. 667-673 ◽  
Author(s):  
Gary W. Lawrence ◽  
J. Oliver Dolly
Keyword(s):  
Chromaffin Cells ◽  
Botulinum Neurotoxin ◽  
Early Stage ◽  
Botulinum Toxin Type A ◽  
Type A ◽  
Snare Complex ◽  
Relative Molecular Mass ◽  
Botulinum Neurotoxin A ◽  
Sds Page ◽  
Wide Range

The changes that SNAREs undergo during exocytosis were studied in permeabilised chromaffin cells treated with Ca2+, MgATP or botulinum neurotoxin A. High-resolution 2D SDS-PAGE revealed multiple SDS-resistant SNARE complexes having a wide range of sizes and in which SNAP-25 and syntaxin predominate over synaptobrevin. Their formation increased upon Ca2+-stimulated exocytosis; notably, the 2D protocol proved much superior to 1D SDS-PAGE for the detection of large complexes and revealed that for forms with relative molecular mass greater than 100,000 stimulated induction was more significant than for smaller species. MgATP enhanced Ca2+-triggered catecholamine release but reduced the content of complexes. By contrast, botulinum neurotoxin type A inhibited exocytosis and altered the stoichiometry of the SNAP-25:syntaxin binary association, without lowering its abundance. The individual SNAREs were protected against trypsin proteolysis to varying extents in binary and ternary complexes of different sizes, suggestive of distinct folding intermediates. Our data suggest that Ca2+ triggers an early stage of SNARE complex formation causing an accumulation of partially folded intermediates, especially of binary forms, as well as their maturation into smaller, more protease resistant states. In addition, botulinum neurotoxin A inhibits exocytosis by perturbing the syntaxin:SNAP-25 ratio in binary intermediates.

scholarly journals Inhibition of Vesicular Secretion in Both Neuronal and Nonneuronal Cells by a Retargeted Endopeptidase Derivative ofClostridium botulinum Neurotoxin Type A

2000 ◽  
Vol 68 (5) ◽  
pp. 2587-2593 ◽  
Author(s):  
John A. Chaddock ◽  
John R. Purkiss ◽  
Lorna M. Friis ◽  
Janice D. Broadbridge ◽  
Michael J. Duggan ◽  
...  
Keyword(s):  
Neurotransmitter Release ◽  
Botulinum Neurotoxin ◽  
Type A ◽  
Cell Types ◽  
Snare Complex ◽  
Cell Binding ◽  
Vesicle Docking ◽  
Botulinum Neurotoxin Type A ◽  
Clostridial Neurotoxins ◽  
Dose Dependent

ABSTRACT Clostridial neurotoxins potently and specifically inhibit neurotransmitter release in defined cell types by a mechanism that involves cleavage of specific components of the vesicle docking/fusion complex, the SNARE complex. A derivative of the type A neurotoxin fromClostridium botulinum (termed LHN/A) that retains catalytic activity can be prepared by proteolysis. The LHN/A, however, lacks the putative native binding domain (HC) of the neurotoxin and is thus unable to bind to neurons and effect inhibition of neurotransmitter release. Here we report the chemical conjugation of LHN/A to an alternative cell-binding ligand, wheat germ agglutinin (WGA). When applied to a variety of cell lines, including those that are ordinarily resistant to the effects of neurotoxin, WGA-LHN/A conjugate potently inhibits secretory responses in those cells. Inhibition of release is demonstrated to be ligand mediated and dose dependent and to occur via a mechanism involving endopeptidase-dependent cleavage of the natural botulinum neurotoxin type A substrate. These data confirm that the function of the HC domain of C. botulinumneurotoxin type A is limited to binding to cell surface moieties. The data also demonstrate that the endopeptidase and translocation functions of the neurotoxin are effective in a range of cell types, including those of nonneuronal origin. These observations lead to the conclusion that a clostridial endopeptidase conjugate that can be used to investigate SNARE-mediated processes in a variety of cells has been successfully generated.

Longitudinal Phonatory Characteristics After Botulinum Toxin Type A Injection

1996 ◽  
Vol 39 (5) ◽  
pp. 968-980 ◽  
Author(s):  
Kimberly V. Fisher ◽  
Ronald C. Scherer ◽  
Chwen G. Guo ◽  
Ann S. Owen
Keyword(s):  
Botulinum Toxin ◽  
Botulinum Toxin Type A ◽  
Type A ◽  
Botulinum Toxin Type ◽  
Spasmodic Dysphonia ◽  
Adductor Spasmodic Dysphonia ◽  
Wide Range ◽  
Glottal Flow ◽  
Vocal Quality ◽  
The Voice

Following Botulinum Toxin Type A injection, glottal competency of an adductor spasmodic dysphonia patient is thought to vary over a wide range. This study quantifies variability in laryngeal adduction for one such patient over a 10-week period. Analyses of kinematic and aerodynamic measures were used to track the voice weekly. The measures included the electroglottographic waveform width (EGGW50), nondimensional electroglottographic slope quotient (SLQ), glottal flow open quotient (FOQ), dc glottal flow, and nondimensional glottal flow peak quotient (FPQ). The results suggested that change in degree of glottal adduction over time can be observed even when vocal instability is present within each recording session. Perceptual ratings of vocal quality (breathy to pressed) were related to the laryngeal measures. The coefficient of variation for EGGW50 and the percentage of dichrotic phonations reached minima during sessions with predominantly breathy and hypoadducted phonation. The methods used in this study show potential to aid decisions about dose level and sources of perceptual adductor spasmodic dysphonia symptoms for a given patient.

scholarly journals Analysis of Gene Expression in Induced Pluripotent Stem Cell-Derived Human Neurons Exposed to Botulinum Neurotoxin A Subtype 1 and a Type A Atoxic Derivative

PLoS ONE ◽  
2014 ◽  
Vol 9 (10) ◽  
pp. e111238 ◽  
Author(s):  
Jacob M. Scherf ◽  
Xiaoyang Serene Hu ◽  
William H. Tepp ◽  
Konstantin Ichtchenko ◽  
Eric A. Johnson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cell ◽  
Pluripotent Stem Cell ◽  
Botulinum Neurotoxin ◽  
Induced Pluripotent Stem Cell ◽  
Type A ◽  
Botulinum Neurotoxin A ◽  
Human Neurons ◽  
Induced Pluripotent

scholarly journals Differential inhibition by botulinum neurotoxin A of cotransmitters released from autonomic vasodilator neurons

2001 ◽  
Vol 281 (5) ◽  
pp. H2124-H2132 ◽  
Author(s):  
Judy L. Morris ◽  
Phillip Jobling ◽  
Ian L. Gibbins
Keyword(s):  
Botulinum Neurotoxin ◽  
Snare Complex ◽  
Snare Proteins ◽  
Botulinum Neurotoxin A ◽  
Uterine Arteries ◽  
Synaptic Vesicle Exocytosis ◽  
Protein Receptor ◽  
Autonomic Neurons ◽  
Vesicle Exocytosis

The role of the soluble NSF attachment protein receptor (SNARE) protein complex in release of multiple cotransmitters from autonomic vasodilator neurons was examined in isolated segments of guinea pig uterine arteries treated with botulinum neurotoxin A (BoNTA; 50 nM). Western blotting of protein extracts from uterine arteries demonstrated partial cleavage of synaptosomal-associated protein of 25 kDa (SNAP-25) to a NH2-terminal fragment of ∼24 kDa by BoNTA. BoNTA reduced the amplitude (by 70–80%) of isometric contractions of arteries in response to repeated electrical stimulation of sympathetic axons at 1 or 10 Hz. The amplitude of neurogenic relaxations mediated by neuronal nitric oxide (NO) was not affected by BoNTA, whereas the duration of peptide-mediated neurogenic relaxations to stimulation at 10 Hz was reduced (67% reduction in integrated responses). In contrast, presynaptic cholinergic inhibition of neurogenic relaxations was abolished by BoNTA. These results demonstrate that the SNARE complex has differential involvement in release of cotransmitters from the same autonomic neurons: NO release is not dependant on synaptic vesicle exocytosis, acetylcholine release from small vesicles is highly dependant on the SNARE complex, and neuropeptide release from large vesicles involves SNARE proteins that may interact differently with regulatory factors such as calcium.

scholarly journals A Moving Residual Limb: Botulinum Toxin to the Rescue

2020 ◽  
Vol 11 (1) ◽  
pp. 34-37 ◽  
Author(s):  
Marie-Michèle Briand ◽  
Mathieu Boudier-Réveret ◽  
Xavier Rodrigue ◽  
Geneviève Sirois ◽  
Min Cheol Chang
Keyword(s):  
Botulinum Toxin ◽  
Botulinum Neurotoxin ◽  
Rare Complication ◽  
Botulinum Toxin Type A ◽  
Type A ◽  
Botulinum Toxin Type ◽  
Residual Limb ◽  
Satisfaction Level ◽  
Botulinum Neurotoxin Type A ◽  
Standardized Treatment

AbstractMovement disorders post-amputation are a rare complication and can manifest as the jumping stump phenomenon, a form of peripheral myoclonus. The pathophysiology remains unknown and there is currently no standardized treatment. We describe the case of a 57-year-old male with unremitting stump myoclonus, starting one month after transtibial amputation, in his residual limb without associated phantom or neurological pain. The consequence of the myoclonus was a reduction in prosthetic wearing time. Failure to respond to oral medication led us to attempt the use of botulinum neurotoxin Type A injections in the involved muscles of the residual limb. Injection trials, over a two-year period, resulted in an improvement of movement disorder, an increased prosthetic wearing time and a higher satisfaction level of the patient. Injection of botulinum toxin type A should be considered as an alternative treatment for stump myoclonus to improve prosthetic wearing time and comfort.

scholarly journals The Pharmacology of Botulinum Toxin Type A

2022 ◽  
Author(s):  
Anna V. Reznik
Keyword(s):  
Botulinum Neurotoxin ◽  
Molecular Mechanisms ◽  
Biological Effects ◽  
Botulinum Toxin Type A ◽  
Type A ◽  
Zinc Metabolism ◽  
Pharmacokinetics And Pharmacodynamics ◽  
Factors Affecting ◽  
Body Distribution ◽  
Treatment Safety

The aim of this chapter is to structure current information clarifying the most disputable issues of botulinum neurotoxin type A (BoNT/A) pharmacology after systemic (botulism) impact and local medical application. Botulinum neurotoxin (BoNT) pharmacological features evaluated open ways to study factors affecting its biological activity: to extend/shorten its effect duration, to increase/decrease BoNT sensitivity in specific patient populations. The chapter presents unique molecular mechanisms underlying BoNT/A pharmacokinetics and pharmacodynamics: entering the body, distribution, receptor binding, translocation, mediator release suppression, zinc metabolism as well as factors affecting body sensitivity to BoNT at each of those stages. The specific biological effects of BoNT/A, which may underlie its analgesic, anticancer and anti-inflammatory effects, are described. Botulinum neurotoxin pharmacokinetics and pharmacodynamics features discussed herein represent significant clinical relevance since they determine botulinum treatment safety and effectiveness. And also they open ways to develop both BoNT-based therapies and anti-botulinic agents.

Dual effects of botulinum neurotoxin A on the secretory stages of chromaffin cells

1998 ◽  
Vol 10 (11) ◽  
pp. 3369-3378 ◽  
Author(s):  
Anabel Gil ◽  
Salvador Viniegra ◽  
Luis M. Gutiérrez
Keyword(s):  
Chromaffin Cells ◽  
Botulinum Neurotoxin ◽  
Botulinum Neurotoxin A

Effects of intra-articular botulinum toxin type A (Botox®) in dogs with chronic osteoarthritis

2010 ◽  
Vol 23 (04) ◽  
pp. 254-258 ◽  
Author(s):  
J. L. Wheeler ◽  
S. W. Petersen ◽  
H. S. Hadley
Keyword(s):  
Botulinum Neurotoxin ◽  
Botulinum Toxin Type A ◽  
Hip Osteoarthritis ◽  
Type A ◽  
Botulinum Toxin Type ◽  
Ground Reaction Forces ◽  
Vertical Force ◽  
Multimodal Approach ◽  
Botulinum Neurotoxin Type A ◽  
Reaction Forces

Summary Objectives: To evaluate the effects of intra-articular botulinum neurotoxin type A (BoNT/A) in dogs with chronic osteo-arthritis. Methods: Client-owned dogs with lameness and discomfort attributed to unilateral elbow or hip osteoarthritis were eligible for inclusion (n = 5). All dogs had BoNT/A (25 units) administered to the affected joint (2 elbows, 3 hips). Dogs were evaluated by pressure platform gait analysis before and at two, four, eight, and 12 weeks post-injection, and by client perception of outcome. Results: In experimental limbs, ground reaction forces (peak vertical force and vertical impulse) consistently improved for a variable period of time following intra-articular BoNT/A therapy. These changes were not, however, observed in the contralateral limbs, in which values remained relatively unchanged or decreased. Four out of five owners reported at least some improvement in their dog’s condition following treatment. Clinical significance: A multimodal approach with the intra-articular administration of BoNT/A may be an option for osteoarthritis patients that are unresponsive to medical management and unable to undergo surgery. However, the findings of this study are preliminary and must be verified by further investigation.

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