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Strickland JB, Davis-Anderson K, Micheva-Viteva S, Twary S, Iyer R, Harris JF, Solomon EA. Optimization of Application-Driven Development of In Vitro Neuromuscular Junction Models. TISSUE ENGINEERING. PART B, REVIEWS 2022; 28:1180-1191. [PMID: 35018825 PMCID: PMC9805869 DOI: 10.1089/ten.teb.2021.0204] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Neuromuscular junctions (NMJs) are specialized synapses responsible for signal transduction between motor neurons (MNs) and skeletal muscle tissue. Malfunction at this site can result from developmental disorders, toxic environmental exposures, and neurodegenerative diseases leading to severe neurological dysfunction. Exploring these conditions in human or animal subjects is restricted by ethical concerns and confounding environmental factors. Therefore, in vitro NMJ models provide exciting opportunities for advancements in tissue engineering. In the last two decades, multiple NMJ prototypes and platforms have been reported, and each model system design is strongly tied to a specific application: exploring developmental physiology, disease modeling, or high-throughput screening. Directing the differentiation of stem cells into mature MNs and/or skeletal muscle for NMJ modeling has provided critical cues to recapitulate early-stage development. Patient-derived inducible pluripotent stem cells provide a personalized approach to investigating NMJ disease, especially when disease etiology cannot be resolved down to a specific gene mutation. Having reproducible NMJ culture replicates is useful for high-throughput screening to evaluate drug toxicity and determine the impact of environmental threat exposures. Cutting-edge bioengineering techniques have propelled this field forward with innovative microfabrication and design approaches allowing both two-dimensional and three-dimensional NMJ culture models. Many of these NMJ systems require further validation for broader application by regulatory agencies, pharmaceutical companies, and the general research community. In this summary, we present a comprehensive review on the current state-of-art research in NMJ models and discuss their ability to provide valuable insight into cell and tissue interactions. Impact statement In vitro neuromuscular junction (NMJ) models reveal the specialized mechanisms of communication between neurons and muscle tissue. This site can be disrupted by developmental disorders, toxic environmental exposures, or neurodegenerative diseases, which often lead to fatal outcomes and is therefore of critical importance to the medical community. Many bioengineering approaches for in vitro NMJ modeling have been designed to mimic development and disease; other approaches include in vitro NMJ models for high-throughput toxicology screening, providing a platform to limit or replace animal testing. This review describes various NMJ applications and the bioengineering advancements allowing for human NMJ characteristics to be more accurately recapitulated. While the extensive range of NMJ device structures has hindered standardization attempts, there is still a need to harmonize these devices for broader application and to continue advancing the field of NMJ modeling.
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Affiliation(s)
- Julie B. Strickland
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - Katie Davis-Anderson
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | | | - Scott Twary
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - Rashi Iyer
- Information System and Modeling, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | | | - Emilia A. Solomon
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico, USA.,Address correspondence to: Emilia A. Solomon, PhD, Bioscience Division, Los Alamos National Laboratory, PO Box 1663 MS M888, Los Alamos, NM 87545, USA
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Périer C, Martin V, Cornet S, Favre‐Guilmard C, Rocher M, Bindler J, Wagner S, Andriambeloson E, Rudkin B, Marty R, Vignaud A, Beard M, Lezmi S, Kalinichev M. Recombinant botulinum neurotoxin serotype A1 in vivo characterization. Pharmacol Res Perspect 2021; 9:e00857. [PMID: 34632725 PMCID: PMC8502944 DOI: 10.1002/prp2.857] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 08/02/2021] [Accepted: 08/04/2021] [Indexed: 12/27/2022] Open
Abstract
Clinically used botulinum neurotoxins (BoNTs) are natural products of Clostridium botulinum. A novel, recombinant BoNT type A1 (rBoNT/A1; IPN10260) has been synthesized using the native amino acid sequence expressed in Escherichia coli and has previously been characterized in vitro and ex vivo. Here, we aimed to characterize rBoNT/A1 in vivo and evaluate its effects on skeletal muscle. The properties of rBoNT/A1 following single, intramuscular administration were evaluated in the mouse and rat digit abduction score (DAS) assays and compared with those of natural BoNT/A1 (nBoNT/A1). rBoNT/A1-injected tibialis anterior was assessed in the in situ muscle force test in rats. rBoNT/A1-injected gastrocnemius lateralis (GL) muscle was assessed in the compound muscle action potential (CMAP) test in rats. The rBoNT/A1-injected GL muscle was evaluated for muscle weight, volume, myofiber composition and immunohistochemical detection of cleaved SNAP25 (c-SNAP25). Results showed that rBoNT/A1 and nBoNT/A1 were equipotent and had similar onset and duration of action in both mouse and rat DAS assays. rBoNT/A1 caused a dose-dependent inhibition of muscle force and a rapid long-lasting reduction in CMAP amplitude that lasted for at least 30 days. Dose-dependent reductions in GL weight and volume and increases in myofiber atrophy were accompanied by immunohistochemical detection of c-SNAP25. Overall, rBoNT/A1 and nBoNT/A1 exhibited similar properties following intramuscular administration. rBoNT/A1 inhibited motoneurons neurotransmitter release, which was robust, long-lasting, and accompanied by cleavage of SNAP25. rBoNT/A1 is a useful tool molecule for comparison with current natural and future modified recombinant neurotoxins products.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Brian Rudkin
- CARPACCIO.cloudLyonFrance
- Univ Lyon, Université Lyon 1, INSERMStem Cell and Brain Research Institute U120BronFrance
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3
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Abstract
Background: With the flourishing application of botulinum toxin cosmetically and therapeutically is the emergence of iatrogenic botulism, a new type of botulism in addition to the traditional ones. Objectives: We aim at a comprehensive review of the clinical characteristics of iatrogenic botulism. Methods: The available publications are retrieved and studied. Results: Botulinum toxin blocks cholinergic transmission in the neuromuscular junctions and autonomic ganglia. The blockade can spread from the site of tissue injection to adjacent or sometimes far off structures, resulting in inadvertent disabling or even lethal effects. On literature review, weakness and dysphagia are the commonest complications of iatrogenic botulism, whereas ophthalmological and oropharyngeal symptoms are more prevalent in the cosmetic group and dyspnea in the therapeutic group. Antitoxin therapy is required in about 20% of the patients. Diagnosis of iatrogenic botulism is primarily clinical and should not be confused with the neurological diagnoses possessing similar clinical manifestations. Vigilance to the drug formulation, dosage, and administration during botulinum toxin injection are part of the preventive measures in minimizing the occurrence of iatrogenic botulism. Conclusion: While overlapping with the traditional types of botulism, iatrogenic botulism carries its unique clinical characteristics.
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Affiliation(s)
- Hin Tat Fung
- Accident & Emergency Department, Tuen Mun Hospital, Tuen Mun, Hong Kong
| | - Ka Man Chan
- Accident & Emergency Department, Tuen Mun Hospital, Tuen Mun, Hong Kong
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Schenke M, Schjeide BM, Püschel GP, Seeger B. Analysis of Motor Neurons Differentiated from Human Induced Pluripotent Stem Cells for the Use in Cell-Based Botulinum Neurotoxin Activity Assays. Toxins (Basel) 2020; 12:toxins12050276. [PMID: 32344847 PMCID: PMC7291138 DOI: 10.3390/toxins12050276] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 04/12/2020] [Accepted: 04/23/2020] [Indexed: 01/03/2023] Open
Abstract
Botulinum neurotoxins (BoNTs) are potent neurotoxins produced by bacteria, which inhibit neurotransmitter release, specifically in their physiological target known as motor neurons (MNs). For the potency assessment of BoNTs produced for treatment in traditional and aesthetic medicine, the mouse lethality assay is still used by the majority of manufacturers, which is ethically questionable in terms of the 3Rs principle. In this study, MNs were differentiated from human induced pluripotent stem cells based on three published protocols. The resulting cell populations were analyzed for their MN yield and their suitability for the potency assessment of BoNTs. MNs produce specific gangliosides and synaptic proteins, which are bound by BoNTs in order to be taken up by receptor-mediated endocytosis, which is followed by cleavage of specific soluble N-ethylmaleimide-sensitive-factor attachment receptor (SNARE) proteins required for neurotransmitter release. The presence of receptors and substrates for all BoNT serotypes was demonstrated in MNs generated in vitro. In particular, the MN differentiation protocol based on Du et al. yielded high numbers of MNs in a short amount of time with high expression of BoNT receptors and targets. The resulting cells are more sensitive to BoNT/A1 than the commonly used neuroblastoma cell line SiMa. MNs are, therefore, an ideal tool for being combined with already established detection methods.
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Affiliation(s)
- Maren Schenke
- Institute for Food Toxicology, Department of Food Toxicology and Replacement/Complementary Methods to Animal Testing, University of Veterinary Medicine, 30173 Hannover, Germany;
| | - Brit-Maren Schjeide
- Institute of Nutritional Science, Department of Nutritional Biochemistry, University of Potsdam, 14558 Nuthetal, Germany; (B.-M.S.); (G.P.P.)
| | - Gerhard P. Püschel
- Institute of Nutritional Science, Department of Nutritional Biochemistry, University of Potsdam, 14558 Nuthetal, Germany; (B.-M.S.); (G.P.P.)
| | - Bettina Seeger
- Institute for Food Toxicology, Department of Food Toxicology and Replacement/Complementary Methods to Animal Testing, University of Veterinary Medicine, 30173 Hannover, Germany;
- Correspondence:
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5
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Yuan H, Silberstein SD. The Use of Botulinum Toxin in the Management of Headache Disorders. Handb Exp Pharmacol 2020; 263:227-249. [PMID: 32562057 DOI: 10.1007/164_2020_365] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Tremendous progress has been made in the past decades for the treatment of headache disorders. Chronic migraine is the most disabling type of headache and requires the use of acute and preventive medications, many of which are associated with adverse events that limit patient adherence. Botulinum toxin (BoNT) serotype A, a neurotoxin derived from certain strains of Clostridium, disrupts neuropeptide secretion and receptor translocation related to trigeminal nociception, thereby preventing pain sensitization through peripheral and possibly central mechanisms. Ever since the first randomized controlled trial on onabotulinumtoxinA (onabotA) for migraine was published two decades ago, onabotA has been the only BoNT formulation approved for use in the prevention of chronic migraine. Superior tolerability and efficacy have been demonstrated on multiple migraine endpoints in many controlled trials and real-life studies. OnabotA is a safe and efficacious treatment for chronic migraine and possibly high-frequency episodic migraine. Further research is still needed to understand its mechanism of action to fully develop its therapeutic potential.
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Affiliation(s)
- Hsiangkuo Yuan
- Jefferson Headache Center, Thomas Jefferson University, Philadelphia, PA, USA
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6
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Dutra EH, Yadav S. The effects on the mandibular condyle of Botox injection into the masseter are not transient. Am J Orthod Dentofacial Orthop 2019; 156:193-202. [PMID: 31375229 DOI: 10.1016/j.ajodo.2018.08.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 08/01/2018] [Accepted: 08/01/2018] [Indexed: 12/13/2022]
Abstract
OBJECTIVES To evaluate whether the effects on the mandibular condylar cartilage (MCC) and subchondral bone are transient of botulinum neurotoxin (Botox) injection into the masseter muscle. METHODS Botox (0.3 U) was injected into the right masseter of 6-week-old female mice (C57BL/6; n = 16). In addition, 16 mice were used as control and received no injections. Experimental and matching control mice were killed 4 or 8 weeks after the single Botox injection. Mandibles and mandibular condyles were analyzed by means of microscopic computed tomography (microCT) and histology. Sagittal sections of condyles were stained for tartrate-resistant acid phosphatase (TRAP), toluidine blue, 5-ethynyl-2'-deoxyuridine (EdU), and terminal deoxynucleotide transferase-mediated dUTP nick-end labeling. RESULTS Bone volume fraction was significantly decreased on the subchondral bone of the Botox-injected side, compared with the control side and control mice, 4 and 8 weeks after injection. Furthermore, histologic analysis revealed decrease in mineralization, cartilage thickness, TRAP activity, and EdU-positive cells in the MCC of the Botox-injected side 4 and 8 weeks after injection. CONCLUSIONS The effects on the MCC and subchondral bone of Botox injection into the masseter muscle persisted for 8 weeks after injection and were not considered to be transient.
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Affiliation(s)
- Eliane H Dutra
- Division of Orthodontics, University of Connecticut Health Center, Farmington, Conn
| | - Sumit Yadav
- Division of Orthodontics, University of Connecticut Health Center, Farmington, Conn.
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7
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Matak I, Bölcskei K, Bach-Rojecky L, Helyes Z. Mechanisms of Botulinum Toxin Type A Action on Pain. Toxins (Basel) 2019; 11:E459. [PMID: 31387301 PMCID: PMC6723487 DOI: 10.3390/toxins11080459] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Revised: 07/26/2019] [Accepted: 07/29/2019] [Indexed: 12/31/2022] Open
Abstract
Already a well-established treatment for different autonomic and movement disorders, the use of botulinum toxin type A (BoNT/A) in pain conditions is now continuously expanding. Currently, the only approved use of BoNT/A in relation to pain is the treatment of chronic migraines. However, controlled clinical studies show promising results in neuropathic and other chronic pain disorders. In comparison with other conventional and non-conventional analgesic drugs, the greatest advantages of BoNT/A use are its sustained effect after a single application and its safety. Its efficacy in certain therapy-resistant pain conditions is of special importance. Novel results in recent years has led to a better understanding of its actions, although further experimental and clinical research is warranted. Here, we summarize the effects contributing to these advantageous properties of BoNT/A in pain therapy, specific actions along the nociceptive pathway, consequences of its central activities, the molecular mechanisms of actions in neurons, and general pharmacokinetic parameters.
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Affiliation(s)
- Ivica Matak
- Department of Pharmacology, University of Zagreb School of Medicine, Šalata 11, 10000 Zagreb, Croatia.
| | - Kata Bölcskei
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, Szigeti út 12, 7624 Pécs, Hungary
- János Szentágothai Research Center, Center for Neuroscience, University of Pécs, Ifjúság útja 20, 7624 Pécs, Hungary
| | - Lidija Bach-Rojecky
- Department of Pharmacology, University of Zagreb Faculty of Pharmacy and Biochemistry, Domagojeva 2, 10000 Zagreb, Croatia
| | - Zsuzsanna Helyes
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, Szigeti út 12, 7624 Pécs, Hungary
- János Szentágothai Research Center, Center for Neuroscience, University of Pécs, Ifjúság útja 20, 7624 Pécs, Hungary
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8
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Ramachandran R, Yaksh TL. Therapeutic use of botulinum toxin in migraine: mechanisms of action. Br J Pharmacol 2015; 171:4177-92. [PMID: 24819339 DOI: 10.1111/bph.12763] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 04/25/2014] [Accepted: 05/02/2014] [Indexed: 12/30/2022] Open
Abstract
Migraine pain represents sensations arising from the activation of trigeminal afferents, which innervate the meningeal vasculature and project to the trigeminal nucleus caudalis (TNC). Pain secondary to meningeal input is referred to extracranial regions innervated by somatic afferents that project to homologous regions in the TNC. Such viscerosomatic convergence accounts for referral of migraine pain arising from meningeal afferents to particular extracranial dermatomes. Botulinum toxins (BoNTs) delivered into extracranial dermatomes are effective in and approved for treating chronic migraine pain. Aside from their well-described effect upon motor endplates, BoNTs are also taken up in local afferent nerve terminals where they cleave soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, and prevent local terminal release. However, a local extracranial effect of BoNT cannot account for allthe effects of BoNT upon migraine. We now know that peripherally delivered BoNTs are taken up in sensory afferents and transported to cleave SNARE proteins in the ganglion and TNC, prevent evoked afferent release and downstream activation. Such effects upon somatic input (as from the face) likewise would not alone account for block of input from converging meningeal afferents. This current work suggests that BoNTs may undergo transcytosis to cleave SNAREs in second-order neurons or in adjacent afferent terminals. Finally, while SNAREs mediate exocytotic release, they are also involved in transport of channels and receptors involved in facilitated pain states. The role of such post-synaptic effects of BoNT action in migraine remains to be determined.
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Affiliation(s)
- Roshni Ramachandran
- Anesthesiology Research, Department of Anesthesiology, University of California, San Diego, La Jolla, CA, USA
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9
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Pantano S, Montecucco C. The blockade of the neurotransmitter release apparatus by botulinum neurotoxins. Cell Mol Life Sci 2014; 71:793-811. [PMID: 23749048 PMCID: PMC11113401 DOI: 10.1007/s00018-013-1380-7] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 05/15/2013] [Accepted: 05/16/2013] [Indexed: 12/22/2022]
Abstract
The high toxicity of the seven serotypes of botulinum neurotoxins (BoNT/A to G), together with their specificity and reversibility, includes them in the list A of potential bioterrorism weapons and, at the same time, among the therapeutics of choice for a variety of human syndromes. They invade nerve terminals and cleave specifically the three proteins which form the heterotrimeric SNAP REceptors (SNARE) complex that mediates neurotransmitter release. The BoNT-induced cleavage of the SNARE proteins explains by itself the paralysing activity of the BoNTs because the truncated proteins cannot form the SNARE complex. However, in the case of BoNT/A, the most widely used toxin in therapy, additional factors come into play as it only removes a few residues from the synaptosomal associate protein of 25 kDa C-terminus and this results in a long duration of action. To explain these facts and other experimental data, we present here a model for the assembly of the neuroexocytosis apparatus in which Synaptotagmin and Complexin first assist the zippering of the SNARE complex, and then stabilize and clamp an octameric radial assembly of the SNARE complexes.
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Affiliation(s)
- Sergio Pantano
- Institut Pasteur de Montevideo, Calle Mataojo 2020, CP 11400 Montevideo, Uruguay
| | - Cesare Montecucco
- Department of Biomedical Sciences, University of Padova, Padua, Italy
- Institute of Neuroscience, National Research Council, Viale G. Colombo 3, 35121 Padua, Italy
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10
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Kutschenko A, Reinert MC, Klinker F, Paulus W, Hesse S, Liebetanz D. Botulinum toxin-induced focal paresis in mice is unaffected by muscle activity. Muscle Nerve 2012; 44:930-6. [PMID: 22102464 DOI: 10.1002/mus.22210] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
INTRODUCTION To test the hypothesis that the efficacy of botulinum toxin depends on the activity of the neuromuscular junction, we developed an in vivo paradigm to determine the degree and duration of low-dose botulinum toxin-induced focal paresis in mice. METHODS We combined an automated wheel-running paradigm with low-dose botulinum toxin injections into the calf muscles of wild-type mice. Half of the mice were injected either before the nightly running or before the daily resting period. RESULTS After botulinum toxin injections, running distance and maximum velocity decreased dose-dependently. The degree and duration of decrease between the respective groups with regard to the time-points of injection were identical. CONCLUSIONS This in vivo paradigm quantifies the degree of otherwise clinically inapparent botulinum toxin-induced focal calf muscle paresis. Increased muscle activity after low-dose injections does not influence the efficacy of botulinum toxin in normal muscles.
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Affiliation(s)
- Anna Kutschenko
- Department of Clinical Neurophysiology, University Medical Centre Göttingen, Göttingen, Germany.
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11
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Matak I, Bach-Rojecky L, Filipović B, Lacković Z. Behavioral and immunohistochemical evidence for central antinociceptive activity of botulinum toxin A. Neuroscience 2011; 186:201-7. [PMID: 21539899 DOI: 10.1016/j.neuroscience.2011.04.026] [Citation(s) in RCA: 134] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2011] [Revised: 04/08/2011] [Accepted: 04/08/2011] [Indexed: 11/29/2022]
Abstract
Botulinum toxin A (BTX-A) is approved for treatment of different cholinergic hyperactivity disorders, and, recently, migraine headache. Although suggested to act only locally, novel observations demonstrated bilateral reduction of pain after unilateral toxin injection, and proposed retrograde axonal transport, presumably in sensory neurons. However, up to now, axonal transport of BTX-A from periphery to CNS was identified only in motoneurons, but with unknown significance. We assessed the effects of low doses of BTX-A injected into the rat whisker pad (3.5 U/kg) or into the sensory trigeminal ganglion (1 U/kg) on formalin-induced facial pain. Axonal transport was prevented by colchicine injection into the trigeminal ganglion (5 mM, 2 μl). To find the possible site of action of axonally transported BTX-A, we employed immunohistochemical labeling of BTX-A-truncated synaptosomal-associated protein 25 (SNAP-25) in medullary dorsal horn of trigeminal nucleus caudalis after toxin injection into the whisker pad. Both peripheral and intraganglionic BTX-A reduce phase II of formalin-induced pain. Antinociceptive effect of BTX-A was prevented completely by colchicine. BTX-A-truncated SNAP-25 in medullary dorsal horn (spinal trigeminal nucleus) was evident 3 days following the peripheral treatment, even with low dose applied (3.5 U/kg). Presented data provide the first evidence that axonal transport of BTX-A, obligatory for its antinociceptive effects, occurs via sensory neurons and is directed to sensory nociceptive nuclei in the CNS.
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Affiliation(s)
- I Matak
- Department of Pharmacology and Croatian Brain Research Institute, University of Zagreb School of Medicine, Zagreb, Croatia
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12
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Lebeda FJ, Cer RZ, Stephens RM, Mudunuri U. Temporal characteristics of botulinum neurotoxin therapy. Expert Rev Neurother 2010; 10:93-103. [PMID: 20021324 PMCID: PMC2842014 DOI: 10.1586/ern.09.134] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Botulinum neurotoxin is a pharmaceutical treatment used for an increasing number of neurological and non-neurological indications, symptoms and diseases. Despite the wealth of clinical reports that involve the timing of the therapeutic effects of this toxin, few studies have attempted to integrate these data into unified models. Secondary reactions have also been examined including the development of adverse events, resistance to repeated applications, and nerve terminal sprouting. Our primary intent for conducting this review was to gather relevant pharmacodynamic data from suitable biomedical literature regarding botulinum neurotoxins via the use of automated data-mining techniques. We envision that mathematical models will ultimately be of value to those who are healthcare decision makers and providers, as well as clinical and basic researchers. Furthermore, we hypothesize that the combination of this computer-intensive approach with mathematical modeling will predict the percentage of patients who will favorably or adversely respond to this treatment and thus will eventually assist in developing the increasingly important area of personalized medicine.
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Affiliation(s)
- Frank J Lebeda
- Combat Casualty Care Research Program, US Army Medical Research and Materiel Command, 504 Scott Street, Ft Detrick, MD 21702-5012, USA, Tel.: +1 301 619 7569, Fax: +1 301 619 7067,
| | - Regina Z Cer
- Advanced Biomedical Computing Center, Advanced Technology Program, SAIC-Frederick Inc., NCI-Frederick, Frederick, MD 21702, USA, Tel.: +1 301 846 5664, Fax: +1 301 846 5762,
| | - Robert M Stephens
- Advanced Biomedical Computing Center, Advanced Technology Program, SAIC-Frederick Inc., NCI-Frederick, Frederick, MD 21702, USA, Tel.: +1 301 846 5787, Fax: +1 301 846 5762,
| | - Uma Mudunuri
- Advanced Biomedical Computing Center, Advanced Technology Program, SAIC-Frederick Inc., NCI-Frederick, Frederick, MD 21702, USA, Tel.: +1 301 846 6774, Fax: +1 301 846 5762,
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Distribution of the high-affinity binding site and intracellular target of botulinum toxin type A in the human bladder. Eur Urol 2009; 57:884-90. [PMID: 20044204 DOI: 10.1016/j.eururo.2009.12.022] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Accepted: 12/10/2009] [Indexed: 11/24/2022]
Abstract
BACKGROUND Botulinum toxin type A (BoNTA) has been successfully used in the treatment of refractory detrusor overactivity. The toxin is internalized after binding a high-affinity receptor, synaptic vesicle protein 2 (SV2), which is exposed in the cell membrane during the exocytosis process. In the cytoplasm, BoNTA cleaves specific sites of synaptosomal-associated protein 25 (SNAP-25), preventing the assembly of the synaptic fusion complex SNARE and blocking exocytosis. OBJECTIVE In the present work, the distribution of SV2 and SNAP-25 was first investigated in human bladders. The neurochemistry of BoNTA-sensitive structures was then investigated using markers for parasympathetic, sympathetic, and sensory fibers. DESIGN, SETTING, AND PARTICIPANTS Human bladders were obtained from cadaveric organ donors (age range: 19-74 yr). MEASUREMENTS Bladder sections were processed for single or dual immunofluorescence staining with antibodies against SV2, SNAP-25, β-3 tubulin, vesicular acetylcholine transporter, tyrosine hydroxilase, and calcitonin gene-related peptide. RESULTS AND LIMITATIONS SV2 and SNAP-25 immunoreactive fibers were distributed throughout the suburothelium and muscular layer. Double labeling showed extensive colocalization of both proteins in nerve fibers. SV2 is more expressed in parasympathetic fibers than in sympathetic or sensory fibers. No expression was found in urothelial or muscular cells. Because only normal bladders were used, this distribution should be applied with caution to pathologic bladders. CONCLUSIONS SV2 and SNAP-25 colocalize abundantly throughout the urinary bladder. SV2 is more abundant in cholinergic, parasympathetic fibers. These nerves are suggested to be the main target for BoNTA action in the human urinary bladder.
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Shi X, Garcia GE, Nambiar MP, Gordon RK. Un-nicked BoNT/B activity in human SHSY-5Y neuronal cells. J Cell Biochem 2008; 105:129-35. [PMID: 18459116 DOI: 10.1002/jcb.21800] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BoNT/B holotoxin (HT) from the native source is a mixture of nicked and un-nicked forms. A previous study showed that while un-nicked HT could be transcytosed by intestinal epithelial cells, they did not correlate this with proteolytic activity or biological effect(s). Un-nicked HT is likely to be present in BoNT biological warfare agents (BWA), so it is important to investigate the relative toxicity of un-nicked HT in this BWA. To address this issue, we purified un-nicked HT from commercial sources and evaluated its ability to cleave substrates both in vitro and in vivo, and its effects on vesicle trafficking. The un-nicked HT was unable to cleave VAMPTide substrate used for in vitro proteolytic assays. Brief digestion of the un-nicked toxin with trypsin resulted in significant activation of the toxin proteolytic ability. SHSY-5Y human neuroblastoma cells were used to examine HT uptake and activation in vivo. Vesicle trafficking can be measured following K(+) stimulation of cells preloaded with [(3)H]-noradrenaline (NA). We found that highly purified un-nicked HT did inhibit NA release but at much reduced levels compared to the nicked toxin. That the reduction in NA release was due to BoNT effects on SNARE proteins was supported by the finding that VAMP-2 protein levels in un-nicked toxin treated cells was greater than those treated with nicked toxin. These results demonstrate that although un-nicked HT has markedly reduced toxicity than the nicked form, due to the preponderance in BoNT/B preparations from the native bacteria, it is a major source of toxicity.
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Affiliation(s)
- Xuerong Shi
- Department of Biochemical Pharmacology, Division of Biochemistry, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, Maryland 20910-7500, USA.
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Onset dynamics of type A botulinum neurotoxin-induced paralysis. J Pharmacokinet Pharmacodyn 2008; 35:251-67. [PMID: 18551355 PMCID: PMC2798021 DOI: 10.1007/s10928-008-9087-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2007] [Accepted: 03/20/2008] [Indexed: 11/29/2022]
Abstract
Experimental studies have demonstrated that botulinum neurotoxin serotype A (BoNT/A) causes flaccid paralysis by a multi-step mechanism. Following its binding to specific receptors at peripheral cholinergic nerve endings, BoNT/A is internalized by receptor-mediated endocytosis. Subsequently its zinc-dependent catalytic domain translocates into the neuroplasm where it cleaves a vesicle-docking protein, SNAP-25, to block neurally evoked cholinergic neurotransmission. We tested the hypothesis that mathematical models having a minimal number of reactions and reactants can simulate published data concerning the onset of paralysis of skeletal muscles induced by BoNT/A at the isolated rat neuromuscular junction (NMJ) and in other systems. Experimental data from several laboratories were simulated with two different models that were represented by sets of coupled, first-order differential equations. In this study, the 3-step sequential model developed by Simpson (J Pharmacol Exp Ther 212:16–21,1980) was used to estimate upper limits of the times during which anti-toxins and other impermeable inhibitors of BoNT/A can exert an effect. The experimentally determined binding reaction rate was verified to be consistent with published estimates for the rate constants for BoNT/A binding to and dissociating from its receptors. Because this 3-step model was not designed to reproduce temporal changes in paralysis with different toxin concentrations, a new BoNT/A species and rate (kS) were added at the beginning of the reaction sequence to create a 4-step scheme. This unbound initial species is transformed at a rate determined by kS to a free species that is capable of binding. By systematically adjusting the values of kS, the 4-step model simulated the rapid decline in NMJ function (kS ≥0.01), the less rapid onset of paralysis in mice following i.m. injections (kS = 0.001), and the slow onset of the therapeutic effects of BoNT/A (kS < 0.001) in man. This minimal modeling approach was not only verified by simulating experimental results, it helped to quantitatively define the time available for an inhibitor to have some effect (tinhib) and the relation between this time and the rate of paralysis onset. The 4-step model predicted that as the rate of paralysis becomes slower, the estimated upper limits of (tinhib) for impermeable inhibitors become longer. More generally, this modeling approach may be useful in studying the kinetics of other toxins or viruses that invade host cells by similar mechanisms, e.g., receptor-mediated endocytosis.
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Drug Insight: biological effects of botulinum toxin A in the lower urinary tract. ACTA ACUST UNITED AC 2008; 5:319-28. [PMID: 18461049 DOI: 10.1038/ncpuro1124] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Accepted: 03/26/2008] [Indexed: 12/29/2022]
Abstract
Botulinum toxins can effectively and selectively disrupt and modulate neurotransmission in striated muscle. Recently, urologists have become interested in the use of these toxins in patients with detrusor overactivity and other urological disorders. In both striated and smooth muscle, botulinum toxin A (BTX-A) is internalized by presynaptic neurons after binding to an extracellular receptor (ganglioside and presumably synaptic vesicle protein 2C). In the neuronal cytosol, BTX-A disrupts fusion of the acetylcholine-containing vesicle with the neuronal wall by cleaving the SNAP-25 protein in the synaptic fusion complex. The net effect is selective paralysis of the low-grade contractions of the unstable detrusor, while still allowing high-grade contraction that initiates micturition. Additionally, BTX-A seems to have effects on afferent nerve activity by modulating the release of ATP in the urothelium, blocking the release of substance P, calcitonin gene-related peptide and glutamate from afferent nerves, and reducing levels of nerve growth factor. These effects on sensory feedback loops might not only help to explain the mechanism of BTX-A in relieving symptoms of overactive bladder, but also suggest a potential role for BTX-A in the relief of hyperalgesia associated with lower urinary tract disorders.
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Abstract
Toxins that alter neurotransmitter release from nerve terminals are of considerable scientific and clinical importance. Many advances were recently made in the understanding of their molecular mechanisms of action and use in human therapy. Here, we focus on presynaptic neurotoxins, which are very potent inhibitors of the neurotransmitter release because they are endowed with specific enzymatic activities: (1) clostridial neurotoxins with a metallo-proteolytic activity and (2) snake presynaptic neurotoxins with a phospholipase A2 activity.
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Affiliation(s)
- Ornella Rossetto
- Departimento de Scienze Biomediche and Istituto CNR di Neuroscienze, Universita di Padova, Viale G. Colombo 3, 35121, Padova, Italy
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Petro KA, Dyer MA, Yowler BC, Schengrund CL. Disruption of lipid rafts enhances activity of botulinum neurotoxin serotype A. Toxicon 2006; 48:1035-45. [PMID: 17046039 DOI: 10.1016/j.toxicon.2006.08.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2006] [Revised: 08/23/2006] [Accepted: 08/28/2006] [Indexed: 01/28/2023]
Abstract
Botulinum neurotoxin serotype A (BoNT/A), one of seven serotypes of botulinum neurotoxin, is taken up by neurons of the peripheral nervous system. Within the neurons it catalyzes cleavage of the synaptosomal-associated protein having a mass of 25kDa, SNAP-25, thereby blocking neurotransmission. BoNT/A has been shown to interact with SV2, as well as gangliosides that are often found in lipid rafts. Lipid rafts are microdomains that can be found on the outer leaflet of the plasma membrane and are enriched in cholesterol and glycosphingolipids. To determine whether lipid rafts are needed for BoNT/A activity, those associated with the plasma membranes of murine N2a neuroblastoma cells were disrupted using either methyl-beta-cyclodextrin or filipin. Disruption of cholesterol-containing lipid rafts by either reagent did not prevent the action of BoNT/A on N2a cells, in fact activity was enhanced. While our results indicate that disruption of lipid rafts enhances BoNT/A activity, disruption of clathrin-dependent endocytosis appeared to be inhibitory.
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Affiliation(s)
- Kimberly A Petro
- Department of Biochemistry and Molecular Biology, H171, The Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA 17033, USA
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19
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Rosales RL, Bigalke H, Dressler D. Pharmacology of botulinum toxin: differences between type A preparations. Eur J Neurol 2006; 13 Suppl 1:2-10. [PMID: 16417591 DOI: 10.1111/j.1468-1331.2006.01438.x] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Different types of botulinum neurotoxin (BoNT) block different proteins of the soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) protein complex within cholinergic nerve terminals, producing blockade of cholinergic neuromuscular and autonomic synapses. Animal studies indicate the longest duration of action for BoNT type A (BoNTA) followed by types B, F, and E. Diffusion to adjacent and remote muscles may be related to protein composition, dilutions, volume, target muscle selection, and injection technique. A review of head-to-head, randomized, controlled trials of BoNTA preparations (Botox and Dysport) suggests that Dysport tends to have higher efficacy, longer duration, and higher frequency of adverse effects. Conversion factors between the preparations varied, however, and remain controversial. In clinical settings, a Botox:Dysport conversion ratio of 1:3 may be appropriate. Animal studies suggest a conversion ratio of 1:2.5-3. When therapeutic effects between these preparations are attempting to be equalized, Dysport seems to produce more adverse effects. In mice, Botox appears to have a better safety margin than Dysport and BoNTB. In rats, diffusion margins are similar for Botox and Dysport. Jitter derived from stimulation single-fiber EMG of injected and remote muscles show no differences between Botox and Dysport. Atrophy of extrafusal muscle fibers of injected and remote muscles do not differ between the BoNTA preparations.
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Affiliation(s)
- R L Rosales
- Department of Neurology and Psychiatry/Research Center for Health Sciences, University of Santo Tomas and The Center for Movement Disorders, St. Lukes Medical Center, Manila, Philippines.
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20
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Keller JE. Recovery from botulinum neurotoxin poisoning in vivo. Neuroscience 2006; 139:629-37. [PMID: 16490322 DOI: 10.1016/j.neuroscience.2005.12.029] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2005] [Revised: 11/18/2005] [Accepted: 12/01/2005] [Indexed: 12/14/2022]
Abstract
Botulinum neurotoxins cause the disease botulism, which is characterized by prolonged muscle paralysis. In contrast, injections of low doses of purified botulinum neurotoxins do not cause systemic illness but produce localized muscle paralysis that is beneficial for treating several human medical disorders involving uncontrollable muscle contraction. Optimizing the therapeutic efficacy while diminishing adverse reactions requires precise knowledge of toxin potency as well as a clear understanding of how each toxin causes disease. A novel in vivo mouse assay has been used to correlate toxin dosage with the duration of muscle paralysis. Voluntary running activity performed by mice was proportional to the amount of toxin injected into the hind limbs and the subsequent rate of recovery over the ensuing days or weeks was a function of botulinum neurotoxin serotype A or B concentration. Botulinum neurotoxin A produced longer paralysis than botulinum neurotoxin B consistent with human observations. A third serotype, botulinum neurotoxin E, had the shortest duration of action, but unlike the other two toxins, dosage did not influence recovery time. Botulinum neurotoxin A recovery appeared biphasic with the initial phase about two-fold faster than the final phase. Over four weeks, muscle activity had gradually improved following the highest botulinum neurotoxin A dose, reaching about half of the normal running activity. Lower botulinum neurotoxin A doses led to incrementally faster and complete recovery. Persistence of maximum paralysis was exponentially related to botulinum neurotoxin A dosage, with a doubling of the paralysis time occurring with every 25% increase of the toxin concentration. In contrast, the rate of recovery from botulinum neurotoxin B was monophasic relative to toxin dosage and the duration of maximum paralysis was linear relative to dosage. Combinations of botulinum neurotoxin A and B and botulinum neurotoxin A and E were tested and shown to exacerbate paralysis compared with individually administered serotypes.
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Affiliation(s)
- J E Keller
- Laboratory of Bacterial Toxins, Division of Bacterial, Parasitic and Allergenic Products, Center for Biologics Evaluation and Research, Food and Drug Administration, 29 Lincoln Drive, HFM 434, Room 122, Bethesda, MD 20892, USA.
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21
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Ma J, Shen J, Lee CA, Elsaidi GA, Smith TL, Walker FO, Rushing JT, Tan KH, Koman LA, Smith BP. Gene expression of nAChR, SNAP-25 and GAP-43 in skeletal muscles following botulinum toxin A injection: a study in rats. J Orthop Res 2005; 23:302-9. [PMID: 15734240 DOI: 10.1016/j.orthres.2004.08.027] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2004] [Accepted: 08/26/2004] [Indexed: 02/04/2023]
Abstract
PURPOSE Botulinum toxin A (BoNT-A) is used to manage spasticity in cerebral palsy. BoNT-A cleaves SNAP-25 protein, blocking acetylcholine release and weakening the muscle. Nicotinic acetylcholine receptors (nAChR) including alpha, beta, delta, gamma, and epsilon subunits, and GAP-43 protein are associated with functional recovery of neuromuscular junctions (NMJ) following BoNT-A. To better understand the mechanism behind this functional recovery, this study attempted to (1) document changes in NMJ morphometry following BoNT-A, and (2) determine the gene expression of nAChR subunits, SNAP-25, and GAP-43 protein. METHODS In this rat study (46 rats), 6 units/kg body weight of BoNT-A was injected into the gastrocnimus. NMJ morphometry and the time course of gene expression of nAChR subunits, SNAP-25, and GAP-43 were evaluated up to 1year post-injection. RESULTS NMJ morphometry: gutter depth was reduced vs. the control side at two months, and normalizing by 6 months following BoNT. nAChR alpha mRNA and gamma mRNA increased by 3 days, peaked at 7 days and returned to control levels; delta mRNA peaked at 3 days. Epsilon mRNA peaked by 7 days. SNAP-25 mRNA increased from 60 to 90 days, returning to control levels by 6 months. GAP-43 mRNA was unchanged. CONCLUSIONS Specific nAChR subunit mRNA expression up-regulates and then returns to normal within two weeks, preceding changes in NMJ morphometry. Although GAP-43 participates in nerve sprouting, no increase of GAP-43 mRNA occurred following BoNT-A. Delayed up-regulation of SNAP-25 mRNA might be associated with muscle functional recovery.
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Affiliation(s)
- Jianjun Ma
- Department of Orthopaedic Surgery, Wake Forest University Health Sciences, Winston-Salem, NC 27157-1070, USA
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Ma J, Elsaidi GA, Smith TL, Walker FO, Tan KH, Martin E, Koman LA, Smith BP. Time Course of Recovery of Juvenile Skeletal Muscle After Botulinum Toxin A Injection. Am J Phys Med Rehabil 2004; 83:774-80; quiz 781-3. [PMID: 15385786 DOI: 10.1097/01.phm.0000137315.17214.93] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE To study the effects of neuromuscular blockade using botulinum toxin A on juvenile muscles at a dosage of 6 units/kg body weight in a rat model. DESIGN A total of 34 male Sprague-Dawley rats (1-mo old) were used. A small incision was made along the posterior aspect of the left hind leg with the exposure of the gastrocnemius. Botulinum toxin A was injected at a dosage of 6 units/kg body weight in the medial and lateral heads of the muscle. An equivalent volume of saline were injected into the right gastrocnemius (control). Motor evoked action potentials, muscle force generation, and muscle mass and neuromuscular junction morphometry were analyzed at different time intervals up to 1 yr after toxin injection. RESULTS During the 1-2 wks after botulinum toxin A injection, muscle mass, electrophysiologic variables, and muscle force generation were significantly reduced but returned to nearly normal at 6 mos postinjection. In the study group, neuromuscular junction gutter depth became significantly shallower 2 mos after injection, then normalized at 1 yr. There was a nonsignificant trend toward larger neuromuscular junctions from the gastrocnemius injected with botulinum toxin A. CONCLUSION Our findings provide scientific evidence to support the clinical situation in which the interinjection interval of 3-6 mos of botulinum toxin A at a similar dosage is used.
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Affiliation(s)
- Jianjun Ma
- Department of Orthopaedic Surgery, Wake Forest University Health Sciences, Winston-Salem, North Carolina 27157, USA
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23
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Whelchel DD, Brehmer TM, Brooks PM, Darragh N, Coffield JA. Molecular targets of botulinum toxin at the mammalian neuromuscular junction. Mov Disord 2004; 19 Suppl 8:S7-S16. [PMID: 15027049 DOI: 10.1002/mds.20004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The molecular targets of botulinum neurotoxins (BoNTs) are SNARE (soluble N-ethylmaleimide-sensitive factor-attachment protein-receptor) proteins necessary for neurotransmitter release. BoNT are powerful therapeutic agents in the treatment of numerous neurological disorders. The goals of this study were to (1) assess toxin diffusion by measuring substrate cleavage in adjacent and distant muscles, and (2) characterize the clinical course using SNARE protein chemistry. A small volume of BoNT/A was injected unilaterally into the mouse gastrocnemius muscle. Motor impairment was limited to the toxin-treated limb. No systemic illness or deaths occurred. At five time points, a subset of mice were killed, and muscles from both hindlimbs, and the diaphragm, were collected. Protein samples were examined for changes in SNAP-25 (synaptosomal-associated protein of Mr = 25 kDa) using immunochemistry. SNAP-25 cleavage product was noted in the toxin-treated limb as early as 1 day postinjection and continued through day 28. Onset and peak levels of substrate cleavage corresponded to the onset and peak clinical response. Cleavage was observed in adjacent and distant muscles, demonstrating that substrate cleavage is a sensitive indicator of toxin diffusion. Significant increases in full-length SNAP-25 and vesicle-associated membrane protein II were evident early in the impaired limb and continued through day 28. The increased SNARE protein most likely originates from nerve terminal sprouts.
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Affiliation(s)
- Dorothy D Whelchel
- Department of Physiology and Pharmacology, College of Veterinary Medicine, The University of Georgia, Athens, 30602, USA
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Fernández-Salas E, Ho H, Garay P, Steward LE, Aoki KR. Is the light chain subcellular localization an important factor in botulinum toxin duration of action? Mov Disord 2004; 19 Suppl 8:S23-34. [PMID: 15027051 DOI: 10.1002/mds.20006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Botulinum neurotoxins (BoNT) are therapeutic proteins that are specific, potent, and effective. They are highly specific in binding to motor neurons but do not bind to other non-neuronal cells. These proteins are zinc-dependent endopeptidases that inhibit exocytosis by specific cleavage of the SNARE (soluble N-ethylmaleimide-sensitive factor-attachment protein-receptor) proteins involved in vesicle docking and fusion. The therapeutic effect of BoNT/A in humans lasts from 3 to 12 months, depending upon the condition treated. Data from animal and cell culture models suggests that the long-lasting duration of inhibition of neurotransmitter release induced by BoNT/A maybe due to the persistence of the endopeptidase activity of the light chain (LC/A) in cells, interactions of the cleaved substrates, and/or the response of the nerve to the temporary disruption of communication with its target tissue. We have analyzed the subcellular localization of the light chains from serotypes A, B, and E and have demonstrated that each light chain displays a distinct distribution within cells. LC/A localizes at the plasma membrane, LC/B is dispersed throughout the cell including the nucleus, and LC/E is mainly cytosolic. Localization is similar in non-neuronal cell lines, suggesting that the signals involved in proper subcellular localization are within the LC sequences and the moiety the light chain interacts with is present in both neuronal and non-neuronal cells.
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Affiliation(s)
- Ester Fernández-Salas
- Neurotoxin Research Program, Department of Biological Sciences, Allergan Inc, Irvine, California 92612, USA
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25
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Fernández-Salas E, Steward LE, Ho H, Garay PE, Sun SW, Gilmore MA, Ordas JV, Wang J, Francis J, Aoki KR. Plasma membrane localization signals in the light chain of botulinum neurotoxin. Proc Natl Acad Sci U S A 2004; 101:3208-13. [PMID: 14982988 PMCID: PMC365768 DOI: 10.1073/pnas.0400229101] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Botulinum neurotoxin (BoNT) is a potent biological substance used to treat neuromuscular and pain disorders. Both BoNT type A and BoNT type E display high-affinity uptake into motor neurons and inhibit exocytosis through cleavage of the synaptosome-associated protein of 25 kDa (SNAP25). The therapeutic effects of BoNT/A last from 3 to 12 months, whereas the effects of BoNT/E last less than 4 weeks. Using confocal microscopy and site-specific mutagenesis, we have determined that the protease domain of BoNT/A light chain (BoNT/A-LC) localizes in a punctate manner to the plasma membrane, colocalizing with the cleaved product, SNAP25(197). In contrast, the short-duration BoNT/E serotype is cytoplasmic. Mutations in the BoNT/A-LC have revealed sequences at the N terminus necessary for plasma membrane localization, and an active dileucine motif in the C terminus that is likely involved in trafficking and interaction with adaptor proteins. These data support sequence-specific signals as determinants of intracellular localization and as a basis for the different durations of action in these two BoNT serotypes.
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Affiliation(s)
- Ester Fernández-Salas
- Neurotoxin Research Program, Department of Biological Sciences, Allergan Inc., 2525 Dupont Drive, Irvine, CA 92612-1599, USA.
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Argoff CE. The Use of Botulinum Toxins for Chronic Pain and Headaches. Curr Treat Options Neurol 2003; 5:483-492. [PMID: 14516525 DOI: 10.1007/s11940-996-0016-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The use of botulinum toxin in the management of various neurologic and non-neurologic disorders has grown considerably over the past decade. At the same time, new information regarding the mechanism of action of these toxins has evolved allowing for a greater understanding of the versatility of these agents. Although two types of botulinum toxin (type A Botox and type B Myobloc ) are commercially available in the US, most studies of the use of these toxins for the management of chronic pain and headache have been completed with type A. Data from open-label and retrospective studies as well as clinical practice suggest as strongly as possible that there is a role for these agents, especially Botox, in the management of several chronic headache disorders, including chronic migraine, chronic tension-type, cervicogenic, and cluster headache. Emerging data regarding the use of these agents for so-called "analgesic-rebound" headache also appear impressive; however, as of yet, no multicenter, randomized, controlled studies for any headache type have been published that confirm the results seen in noncontrolled studies. Nevertheless, the benefit that some patients experience from this agent is impressive, and this drug appears for many to modify the disorder in a very positive manner. In a similar fashion, data for other pain states are often restricted to open-label and case study approaches; however, clinical experience and some of the available studies (even small controlled studies) suggest a role for the toxins in the management of various chronic pain states, such as myofascial pain, low back pain, and neuropathic pain. One of the greatest challenges ahead for all interested in this area is confirming the benefit seen clinically through appropriately designed multicenter, randomized, controlled studies.
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Affiliation(s)
- Charles E. Argoff
- Cohn Pain Management Center, North Shore University Hospital and New York University School of Medicine, 4300 Hempstead Turnpike, Bethpage, NY 11714, USA.
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Foran PG, Davletov B, Meunier FA. Getting muscles moving again after botulinum toxin: novel therapeutic challenges. Trends Mol Med 2003; 9:291-9. [PMID: 12900216 DOI: 10.1016/s1471-4914(03)00113-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Patrick G Foran
- Centre for Neurobiochemistry, Department of Biological Sciences, Imperial College, London SW7 2AZ, UK
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Meunier FA, Lisk G, Sesardic D, Dolly JO. Dynamics of motor nerve terminal remodeling unveiled using SNARE-cleaving botulinum toxins: the extent and duration are dictated by the sites of SNAP-25 truncation. Mol Cell Neurosci 2003; 22:454-66. [PMID: 12727443 DOI: 10.1016/s1044-7431(02)00016-7] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Nerve sprouts emerge from motor nerve terminals following blockade of exo-endocytosis for more than 3 days by botulinum neurotoxin (BoNT), and form functional synapses, albeit temporary. Upon restoration of synaptic activity to the parent terminal 7 and 90 days after exposure to BoNT/F or A respectively, a concomitant retraction of the outgrowths was observed. BoNT/E caused short-term neuroparalysis, and dramatically accelerated the recovery of BoNT/A-paralyzed muscle by further truncation of SNAP-25 and its replenishment with functional full-length SNARE. The removal of 9 C-terminal residues from SNAP-25 by BoNT/A leads to persistence of the inhibitory product due to the formation of a nonproductive SNARE complex(es) at release sites, whereas deletion of a further 17 amino acids permits replenishment and a speedy recovery.
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Affiliation(s)
- Frédéric A Meunier
- Centre for Neurobiochemistry, Department of Biological Sciences, Imperial College of Science, Technology and Medicine, London SW7 2AY, UK
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29
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Foran PG, Mohammed N, Lisk GO, Nagwaney S, Lawrence GW, Johnson E, Smith L, Aoki KR, Dolly JO. Evaluation of the therapeutic usefulness of botulinum neurotoxin B, C1, E, and F compared with the long lasting type A. Basis for distinct durations of inhibition of exocytosis in central neurons. J Biol Chem 2003; 278:1363-71. [PMID: 12381720 DOI: 10.1074/jbc.m209821200] [Citation(s) in RCA: 230] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Seven types (A-G) of botulinum neurotoxin (BoNT) target peripheral cholinergic neurons where they selectively proteolyze SNAP-25 (BoNT/A, BoNT/C1, and BoNT/E), syntaxin1 (BoNT/C1), and synaptobrevin (BoNT/B, BoNT/D, BoNT/F, and BoNT/G), SNARE proteins responsible for transmitter release, to cause neuromuscular paralysis but of different durations. BoNT/A paralysis lasts longest (4-6 months) in humans, hence its widespread clinical use for the treatment of dystonias. Molecular mechanisms underlying these distinct inhibitory patterns were deciphered in rat cerebellar neurons by quantifying the half-life of the effect of each toxin, the speed of replenishment of their substrates, and the degradation of the cleaved products, experiments not readily feasible at motor nerve endings. Correlation of target cleavage with blockade of transmitter release yielded half-lives of inhibition for BoNT/A, BoNT/C1, BoNT/B, BoNT/F, and BoNT/E (31, 25, approximately 10, approximately 2, and approximately 0.8 days, respectively), equivalent to the neuromuscular paralysis times found in mice, with recovery of release coinciding with reappearance of the intact SNAREs. A limiting factor for the short neuroparalytic durations of BoNT/F and BoNT/E is the replenishment of synaptobrevin or SNAP-25, whereas pulse labeling revealed that extended inhibition by BoNT/A, BoNT/B, or BoNT/C1 results from longevity of each protease. These novel findings could aid development of new toxin therapies for patients resistant to BoNT/A and effective treatments for human botulism.
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Affiliation(s)
- Patrick G Foran
- Centre for Neurobiochemistry, Department of Biological Sciences, Imperial College, London SW7 2AZ, United Kingdom
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Abstract
The seven botulinum neurotoxin serotypes share less than 50% sequence homology and are immunologically distinct. The neurotoxins inhibit release of the neurotransmitter acetylcholine from the axon terminals of motor neurons, preganglionic sympathetic and parasympathetic neurons, and postganglionic parasympathetic nerves by a multi-step mechanism that differs slightly, but significantly, for each serotype. The inhibition is long lasting but temporary. The resulting muscle paralysis has provided the basis for therapeutic use of botulinum toxin types A and B in a variety of focal dystonias. The safety of the botulinum toxins, when administered focally, has permitted their widespread use in a number of other painful conditions.
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Yowler BC, Kensinger RD, Schengrund CL. Botulinum neurotoxin A activity is dependent upon the presence of specific gangliosides in neuroblastoma cells expressing synaptotagmin I. J Biol Chem 2002; 277:32815-9. [PMID: 12089155 DOI: 10.1074/jbc.m205258200] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Botulinum neurotoxin A (BoNT/A) is the deadliest of all known biological substances. Although its toxicity makes BoNT/A a biological warfare threat, its biologic activity makes it an increasingly useful therapeutic agent for the treatment of muscular disorders. However, almost 200 years after its discovery, the neuronal cell components required for the activity of this deadly toxin have not been unequivocally identified. In this work, neuroblastoma cells expressing synaptotagmin I, a protein shown to be bound by BoNT/A, were used to determine whether specific gangliosides were necessary for BoNT/A activity as measured by synaptosomal-associated protein of 25 kDa (SNAP-25) cleavage. Ganglioside GT1b was found to support BoNT/A activity significantly more effectively than GD1a, which was far more effective than GM1 when added to ganglioside-deficient murine cholinergic Neuro 2a or to human adrenergic SK-N-SH neuroblastoma cells. Whereas both cell lines expressed synaptotagmin I, SNAP-25 cleavage was not observed in the absence of complex gangliosides. These results indicate that 1) gangliosides are required for BoNT/A activity, 2) synaptotagmin I in the absence of gangliosides does not support BoNT/A activity, and 3) Neuro 2a cells are an efficient model system for studying the biological activity of BoNT/A.
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Affiliation(s)
- Brian C Yowler
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
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