101
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Caleo M, Restani L. Exploiting Botulinum Neurotoxins for the Study of Brain Physiology and Pathology. Toxins (Basel) 2018; 10:toxins10050175. [PMID: 29693600 PMCID: PMC5983231 DOI: 10.3390/toxins10050175] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 04/21/2018] [Accepted: 04/23/2018] [Indexed: 01/25/2023] Open
Abstract
Botulinum neurotoxins are metalloproteases that specifically cleave N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins in synaptic terminals, resulting in a potent inhibition of vesicle fusion and transmitter release. The family comprises different serotypes (BoNT/A to BoNT/G). The natural target of these toxins is represented by the neuromuscular junction, where BoNTs block acetylcholine release. In this review, we describe the actions of botulinum toxins after direct delivery to the central nervous system (CNS), where BoNTs block exocytosis of several transmitters, with near-complete silencing of neural networks. The use of clostridial neurotoxins in the CNS has allowed us to investigate specifically the role of synaptic activity in different physiological and pathological processes. The silencing properties of BoNTs can be exploited for therapeutic purposes, for example to counteract pathological hyperactivity and seizures in epileptogenic brain foci, or to investigate the role of activity in degenerative diseases like prion disease. Altogether, clostridial neurotoxins and their derivatives hold promise as powerful tools for both the basic understanding of brain function and the dissection and treatment of activity-dependent pathogenic pathways.
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Affiliation(s)
- Matteo Caleo
- CNR Neuroscience Institute, via G. Moruzzi 1, 56124 Pisa, Italy.
| | - Laura Restani
- CNR Neuroscience Institute, via G. Moruzzi 1, 56124 Pisa, Italy.
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102
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Moga MA, Dimienescu OG, Bălan A, Scârneciu I, Barabaș B, Pleș L. Therapeutic Approaches of Botulinum Toxin in Gynecology. Toxins (Basel) 2018; 10:toxins10040169. [PMID: 29690530 PMCID: PMC5923335 DOI: 10.3390/toxins10040169] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 04/18/2018] [Accepted: 04/19/2018] [Indexed: 12/15/2022] Open
Abstract
Botulinum toxins (BoNTs) are produced by several anaerobic species of the genus Clostridium and, although they were originally considered lethal toxins, today they find their usefulness in the treatment of a wide range of pathologies in various medical specialties. Botulinum neurotoxin has been identified in seven different isoforms (BoNT-A, BoNT-B, BoNT-C, BoNT-D, BoNT-E, BoNT-F, and BoNT-G). Neurotoxigenic Clostridia can produce more than 40 different BoNT subtypes and, recently, a new BoNT serotype (BoNT-X) has been reported in some studies. BoNT-X has not been shown to actually be an active neurotoxin despite its catalytically active LC, so it should be described as a putative eighth serotype. The mechanism of action of the serotypes is similar: they inhibit the release of acetylcholine from the nerve endings but their therapeutically potency varies. Botulinum toxin type A (BoNT-A) is the most studied serotype for therapeutic purposes. Regarding the gynecological pathology, a series of studies based on the efficiency of its use in the treatment of refractory myofascial pelvic pain, vaginism, dyspareunia, vulvodynia and overactive bladder or urinary incontinence have been reported. The current study is a review of the literature regarding the efficiency of BoNT-A in the gynecological pathology and on the long and short-term effects of its administration.
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Affiliation(s)
- Marius Alexandru Moga
- Department of Medical and Surgical Specialties, Faculty of Medicine, Transilvania University of Brasov, Brasov 500019, Romania.
| | - Oana Gabriela Dimienescu
- Department of Medical and Surgical Specialties, Faculty of Medicine, Transilvania University of Brasov, Brasov 500019, Romania.
| | - Andreea Bălan
- Department of Medical and Surgical Specialties, Faculty of Medicine, Transilvania University of Brasov, Brasov 500019, Romania.
| | - Ioan Scârneciu
- Department of Medical and Surgical Specialties, Faculty of Medicine, Transilvania University of Brasov, Brasov 500019, Romania.
| | - Barna Barabaș
- Department of Fundamental Disciplines and Clinical Prevention, Faculty of Medicine, Transilvania University of Brasov, Brasov 500019, Romania.
| | - Liana Pleș
- Clinical Department of Obstetrics and Gynecology, The Carol Davila University of Medicine and Pharmacy, Bucharest 020021, Romania.
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103
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Gustafsson R, Zhang S, Masuyer G, Dong M, Stenmark P. Crystal Structure of Botulinum Neurotoxin A2 in Complex with the Human Protein Receptor SV2C Reveals Plasticity in Receptor Binding. Toxins (Basel) 2018; 10:E153. [PMID: 29649119 PMCID: PMC5923319 DOI: 10.3390/toxins10040153] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 03/28/2018] [Accepted: 04/10/2018] [Indexed: 11/16/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) are a family of highly dangerous bacterial toxins, with seven major serotypes (BoNT/A-G). Members of BoNTs, BoNT/A1 and BoNT/B1, have been utilized to treat an increasing number of medical conditions. The clinical trials are ongoing for BoNT/A2, another subtype of BoNT/A, which showed promising therapeutic properties. Both BoNT/A1 and BoNT/A2 utilize three isoforms of synaptic vesicle protein SV2 (SV2A, B, and C) as their protein receptors. We here present a high resolution (2.0 Å) co-crystal structure of the BoNT/A2 receptor-binding domain in complex with the human SV2C luminal domain. The structure is similar to previously reported BoNT/A-SV2C complexes, but a shift of the receptor-binding segment in BoNT/A2 rotates SV2C in two dimensions giving insight into the dynamic behavior of the interaction. Small differences in key residues at the binding interface may influence the binding to different SV2 isoforms, which may contribute to the differences between BoNT/A1 and BoNT/A2 observed in the clinic.
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Affiliation(s)
- Robert Gustafsson
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden.
| | - Sicai Zhang
- Department of Urology, Boston Children's Hospital, Department of Microbiology and Immunobiology and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA.
| | - Geoffrey Masuyer
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden.
| | - Min Dong
- Department of Urology, Boston Children's Hospital, Department of Microbiology and Immunobiology and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA.
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden.
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104
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Structural characterisation of the catalytic domain of botulinum neurotoxin X - high activity and unique substrate specificity. Sci Rep 2018. [PMID: 29540745 PMCID: PMC5851995 DOI: 10.1038/s41598-018-22842-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) are among the most potent toxins known and are also used to treat an increasing number of medical disorders. There are seven well-established serotypes (BoNT/A-G), which all act as zinc-dependent endopeptidases targeting specific members of the SNARE proteins required for synaptic vesicle exocytosis in neurons. A new toxin serotype, BoNT/X, was recently identified. It cleaves not only the canonical targets, vesicle associated membrane proteins (VAMP) 1/2/3 at a unique site, but also has the unique ability to cleave VAMP4/5 and Ykt6. Here we report the 1.35 Å X-ray crystal structure of the light chain of BoNT/X (LC/X). LC/X shares the core fold common to all other BoNTs, demonstrating that LC/X is a bona fide member of BoNT-LCs. We found that access to the catalytic pocket of LC/X is more restricted, and the regions lining the catalytic pocket are not conserved compared to other BoNTs. Kinetic studies revealed that LC/X cleaves VAMP1 with a ten times higher efficiency than BoNT/B and the tetanus neurotoxin. The structural information provides a molecular basis to understand the convergence/divergence between BoNT/X and other BoNTs, to develop effective LC inhibitors, and to engineer new scientific tools and therapeutic toxins targeting distinct SNARE proteins in cells.
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105
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Yu CH, Song DH, Choi JY, Joe HE, Jeong WH, Hur GH, Shin YK, Jeong ST. A mutated recombinant subunit vaccine protects mice and guinea pigs against botulinum type A intoxication. Hum Vaccin Immunother 2018; 14:329-336. [PMID: 29140753 PMCID: PMC5806659 DOI: 10.1080/21645515.2017.1405201] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 10/17/2017] [Accepted: 11/09/2017] [Indexed: 02/08/2023] Open
Abstract
Botulinum neurotoxins (BoNTs) are the most potent toxins to mammals. A toxoid vaccine was previously used for prevention of botulinum intoxication; however, this vaccine is no longer available. Currently, no approved botulinum vaccines are available from the Food and Drug Administration (FDA). Recently, a recombinant host cell receptor-binding subunit created for use as a potential vaccine completed phase 2 clinical trials. The current study designed a vaccine candidate against BoNT type A (BoNT/A) using a structural design. Our vaccine candidate was the BoNT/A heavy chain C-terminal region (HCR) that contained the point mutation BA15 (R1269A) within the ganglioside-binding site. A Biacore affinity test showed that the affinity of BA15 for ganglioside GT1b was 100 times lower than that of the HCR. A SNAP25 cleavage assay revealed that immunized sera blocked SNAP25 cleavage of the BoNT/A toxin via BA15. In an in vivo experiment, mice and guinea pigs immunized with BA15 produced neutralizing antibodies that protected against 3,000 LD50 of BoNT/A. In conclusion, the results of both in vitro and in vivo assays showed that our BA15 vaccine candidate was similar to the recombinant host cell receptor-binding subunit vaccine. The inability of BA15to bind ganglioside shows that BA15 is a potential safe vaccine candidate.
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Affiliation(s)
- Chi Ho Yu
- Agency for Defense Development, Yuseong, Daejeon, Republic of Korea
| | - Dong Hyun Song
- Agency for Defense Development, Yuseong, Daejeon, Republic of Korea
| | - Jun Young Choi
- Abion R&D Institute, Hanhwa Biz-Metro, Guro-gu, Seoul, Republic of Korea
| | - Hae Eun Joe
- Agency for Defense Development, Yuseong, Daejeon, Republic of Korea
| | - Woo Hyeon Jeong
- Agency for Defense Development, Yuseong, Daejeon, Republic of Korea
| | - Gyeung Haeng Hur
- Agency for Defense Development, Yuseong, Daejeon, Republic of Korea
| | - Young Kee Shin
- Department of Pharmacy, College of Pharmacy, Seoul National University, Dajeon, Seoul, Republic of Korea
| | - Seong Tae Jeong
- Agency for Defense Development, Yuseong, Daejeon, Republic of Korea
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106
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Brunt J, Carter AT, Stringer SC, Peck MW. Identification of a novel botulinum neurotoxin gene cluster in Enterococcus. FEBS Lett 2018; 592:310-317. [PMID: 29323697 PMCID: PMC5838542 DOI: 10.1002/1873-3468.12969] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 12/28/2017] [Accepted: 01/02/2018] [Indexed: 01/02/2023]
Abstract
The deadly neurotoxins of Clostridium botulinum (BoNTs) comprise eight serotypes (A-G; X). The neurotoxin gene cluster encoding BoNT and its accessory proteins includes an operon containing an ntnh gene upstream of the boNT gene. Another operon contains either ha (haemagglutinin) or orfX genes (of unknown function). Here we describe a novel boNT gene cluster from Enterococcus sp. 3G1_DIV0629, with a typical ntnh gene and an uncommon orfX arrangement. The neurotoxin (designated putative eBoNT/J) contains a metallopeptidase zinc-binding site, a translocation domain and a target cell attachment domain. Structural properties of the latter suggest a novel targeting mechanism with consequent implications for application by the pharmaceutical industry. This is the first complete boNT gene cluster identified in a non-clostridial genome.
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Affiliation(s)
- Jason Brunt
- Gut Health and Food SafetyQuadram InstituteNorwichUK
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107
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Bradford AB, Machamer JB, Russo TM, McNutt PM. 3,4-diaminopyridine reverses paralysis in botulinum neurotoxin-intoxicated diaphragms through two functionally distinct mechanisms. Toxicol Appl Pharmacol 2018; 341:77-86. [PMID: 29366638 DOI: 10.1016/j.taap.2018.01.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 01/15/2018] [Accepted: 01/18/2018] [Indexed: 01/11/2023]
Abstract
Botulinum neurotoxins (BoNTs) are exceedingly potent neurological poisons that prevent neurotransmitter release from peripheral nerve terminals by cleaving presynaptic proteins required for synaptic vesicle fusion. The ensuing neuromuscular paralysis causes death by asphyxiation. Although no antidotal treatments exist to block toxin activity within the nerve terminal, aminopyridine antagonists of voltage-gated potassium channels have been proposed as symptomatic treatments for botulism toxemia. However, clinical evaluation of aminopyridines as symptomatic treatments for botulism has been inconclusive, in part because mechanisms responsible for reversal of paralysis in BoNT-poisoned nerve terminals are not understood. Here we measured the effects of 3,4-diaminopyridine (DAP) on phrenic nerve-elicited diaphragm contraction and end-plate potentials at various times after intoxication with BoNT serotypes A, B, or E. We found that DAP-mediated increases in quantal content promote neurotransmission from intoxicated nerve terminals through two functionally distinguishable mechanisms. First, DAP increases the probability of neurotransmission at non-intoxicated release sites. This mechanism is serotype-independent, becomes less effective as nerve terminals become progressively impaired, and remains susceptible to ongoing intoxication. Second, DAP elicits persistent production of toxin-resistant endplate potentials from nerve terminals fully intoxicated by BoNT/A, but not serotypes B or E. Since this effect appears specific to BoNT/A intoxication, we propose that DAP treatment enables BoNT/A-cleaved SNAP-25 to productively engage in fusogenic release by increasing the opportunity for low-efficiency fusion events. These findings have important implications for DAP as a botulism therapeutic by defining conditions under which DAP may be clinically effective in reversing botulism symptoms.
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Affiliation(s)
- Aaron B Bradford
- Department of Neuroscience, United States Army Medical Research Institute of Chemical Defense, 2900 Ricketts Point Road, Gunpowder, MD 21010, USA
| | - James B Machamer
- Department of Neuroscience, United States Army Medical Research Institute of Chemical Defense, 2900 Ricketts Point Road, Gunpowder, MD 21010, USA
| | - Trisha M Russo
- Department of Neuroscience, United States Army Medical Research Institute of Chemical Defense, 2900 Ricketts Point Road, Gunpowder, MD 21010, USA
| | - Patrick M McNutt
- Department of Neuroscience, United States Army Medical Research Institute of Chemical Defense, 2900 Ricketts Point Road, Gunpowder, MD 21010, USA.
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108
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Identification of a Botulinum Neurotoxin-like Toxin in a Commensal Strain of Enterococcus faecium. Cell Host Microbe 2018; 23:169-176.e6. [PMID: 29396040 DOI: 10.1016/j.chom.2017.12.018] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 11/20/2017] [Accepted: 12/14/2017] [Indexed: 12/11/2022]
Abstract
Botulinum neurotoxins (BoNTs), produced by various Clostridium strains, are a family of potent bacterial toxins and potential bioterrorism agents. Here we report that an Enterococcus faecium strain isolated from cow feces carries a BoNT-like toxin, designated BoNT/En. It cleaves both VAMP2 and SNAP-25, proteins that mediate synaptic vesicle exocytosis in neurons, at sites distinct from known BoNT cleavage sites on these two proteins. Comparative genomic analysis determines that the E. faecium strain carrying BoNT/En is a commensal type and that the BoNT/En gene is located within a typical BoNT gene cluster on a 206 kb putatively conjugative plasmid. Although the host species targeted by BoNT/En remains to be determined, these findings establish an extended member of BoNTs and demonstrate the capability of E. faecium, a commensal organism ubiquitous in humans and animals and a leading cause of hospital-acquired multi-drug-resistant (MDR) infections, to horizontally acquire, and possibly disseminate, a unique BoNT gene cluster.
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109
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Pellett S, Tepp WH, Lin G, Johnson EA. Substrate cleavage and duration of action of botulinum neurotoxin type FA ("H, HA"). Toxicon 2017; 147:38-46. [PMID: 29273248 PMCID: PMC5911199 DOI: 10.1016/j.toxicon.2017.12.048] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 12/15/2017] [Accepted: 12/18/2017] [Indexed: 12/12/2022]
Abstract
Botulinum neurotoxin (BoNT) type FA is the only known naturally occurring chimeric BoNT of domains of BoNT/A and BoNT/F. BoNT/FA consists of an F5-like light chain (LC), a unique heavy chain (HC) translocation domain, and a HC receptor binding domain similar to BoNT/A1. Previous analyses of purified BoNT/FA have indicated a 5-10-fold greater potency in cultured human or rat neurons as compared to BoNT/A1 and a 400-500-fold greater potency compared to BoNT/B1. However, in vivo potency in mice was about 5-fold lower than BoNT/A1 or/B1. In this report, species specificity was examined by cell-based assays using primary neurons from mice and examining VAMP1 and 2 cleavage. The data indicated similar potency of BoNT/FA in primary mouse spinal cord neurons as previously observed in primary rat and human induced pluripotent stem cell (hiPSC) derived neuronal cell models, and equal enzymatic cleavage of mouse VAMP1 and 2 isoforms. Since the duration of action of BoNTs is due to continuous enzymatic activity of the LC in the neuronal cytosol, BoNT/FA was expected to have a short duration of action due to its F-type LC. In this report the duration of action of BoNT/FA was compared to that of BoNT/F1,/F5, and/B1 in both hiPSC derived neurons and in the in vivo mouse model. The data indicate a duration of action of BoNT/FA similar to BoNT/B1, while BoNT/F5 had a short duration of action similar to BoNT/F1.
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Affiliation(s)
- Sabine Pellett
- Department of Bacteriology, University of Wisconsin, 1550 Linden Dr., Madison, WI 53706, USA.
| | - William H Tepp
- Department of Bacteriology, University of Wisconsin, 1550 Linden Dr., Madison, WI 53706, USA.
| | - Guangyun Lin
- Department of Bacteriology, University of Wisconsin, 1550 Linden Dr., Madison, WI 53706, USA.
| | - Eric A Johnson
- Department of Bacteriology, University of Wisconsin, 1550 Linden Dr., Madison, WI 53706, USA.
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110
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High Yield Preparation of Functionally Active Catalytic-Translocation Domain Module of Botulinum Neurotoxin Type A That Exhibits Uniquely Different Enzyme Kinetics. Protein J 2017; 36:489-501. [PMID: 29030733 DOI: 10.1007/s10930-017-9744-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Botulinum neurotoxins (BoNTs) are the most toxic proteins known to cause flaccid muscle paralysis as a result of inhibition of neurotransmitter release from peripheral cholinergic synapses. BoNT type A (BoNT/A) is a 150 kDa protein consisting of two major subunits: light chain (LC) and heavy chain (HC). The LC is required for the catalytic activity of neurotoxin, whereas the C and N terminal domains of the HC are required for cell binding, and translocation of LC across the endosome membranes, respectively. To better understand the structural and functional aspects of BoNT/A intoxication we report here the development of high yield Escherichia coli expression system (2-20-fold higher yield than the value reported in the literature) for the production of recombinant light chain-translocation domain (rLC-TD/A) module of BoNT/A which is catalytically active and translocation competent. The open reading frame of rLC-TD/A was PCR amplified from deactivated recombinant BoNT/A gene (a non-select agent reagent), and was cloned using pET45b (+) vector to express in E. coli cells. The purification procedure included a sequential order of affinity chromatography, trypsinization, and anion exchange column chromatography. We were able to purify > 95% pure, catalytically active and structurally well-folded protein. Comparison of enzyme kinetics of purified LC-TD/A to full-length toxin and recombinant light chain A suggest that the affinity for the substrate is in between endopeptidase domain and botulinum toxin. The potential application of the purified protein has been discussed in toxicity and translocation assays.
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111
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Kodihalli S, Emanuel A, Takla T, Hua Y, Hobbs C, LeClaire R, O’Donnell DC. Therapeutic efficacy of equine botulism antitoxin in Rhesus macaques. PLoS One 2017; 12:e0186892. [PMID: 29166654 PMCID: PMC5699824 DOI: 10.1371/journal.pone.0186892] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 10/09/2017] [Indexed: 11/19/2022] Open
Abstract
Background There are currently no licensed vaccines available for prevention of botulism in humans. The vaccination is not desirable due to expanding therapeutic indications of botulinum toxins. The only available specific treatment for botulism is antitoxin to remove circulating toxin, thus, preventing further neuronal damage. BAT® (Botulism Antitoxin Heptavalent (A, B, C, D, E, F, G)—(Equine)) has been developed and its therapeutic efficacy evaluated against botulinum neurotoxin serotype A (BoNT/A) in Rhesus macaques. Methods and findings In a post-exposure prophylaxis (PEP) study, animals were exposed to 4x LD50/kg of BoNT/A and administered intravenously with either BAT (1x or 0.1x scaled human dose), or placebo at 4 hours post-exposure. The animals were monitored for 14 days. For the therapeutic intervention studies, animals were exposed to a 1.7x LD50/kg of BoNT/A and treated intravenously with either placebo or BAT at a 1x scaled human dose at the onset of clinical signs. Animals were monitored on an hourly basis for 14 or 21 days. In the PEP study, all animals tolerated equine based antitoxin without any adverse clinical signs. A 100% survival was observed in groups treated with the BAT compared to 0% survival in those treated with the placebo (p<0.001, Fisher’s exact test). BAT antitoxin prevented the development of signs of neurotoxicity of botulinum toxin. In a therapeutic study, treatment with the BAT at scaled 1x human dose after the onset of clinical signs significantly enhanced survival compared to the placebo (46.6% vs. 0%, p<0.0001, Fisher’s exact test). Additionally, treatment with the BAT delayed the progression of signs (muscular weakness, respiratory distress, oral/nasal discharge) of toxin intoxication and reduced the severity of the disease. Conclusions A single dose of BAT, when administered to symptomatic monkeys, resulted in a statistically significant survival benefit compared to the placebo. Additionally, BAT completely protected monkeys from the clinical signs of intoxication and subsequent death when administered as PEP treatment. These data in part supported the licensure of BAT under the Animal Rule in the United States by the Food and Drug Administration.
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Affiliation(s)
- Shantha Kodihalli
- Research and Development, Emergent BioSolution, Winnipeg, Manitoba, Canada
- * E-mail:
| | - Andrew Emanuel
- Research and Development, Emergent BioSolution, Winnipeg, Manitoba, Canada
| | - Teresa Takla
- Research and Development, Emergent BioSolution, Winnipeg, Manitoba, Canada
| | - Yi Hua
- Clinical Research, Emergent BioSolutions, Winnipeg, Manitoba, Canada
| | - Charles Hobbs
- Lovelace Respiratory Research Institute, Albuquerque, New Mexico, United States of America
| | - Ross LeClaire
- Lovelace Respiratory Research Institute, Albuquerque, New Mexico, United States of America
| | - Denise C. O’Donnell
- Lovelace Respiratory Research Institute, Albuquerque, New Mexico, United States of America
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112
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Zhang S, Berntsson RPA, Tepp WH, Tao L, Johnson EA, Stenmark P, Dong M. Structural basis for the unique ganglioside and cell membrane recognition mechanism of botulinum neurotoxin DC. Nat Commun 2017; 8:1637. [PMID: 29158482 PMCID: PMC5696347 DOI: 10.1038/s41467-017-01534-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 09/25/2017] [Indexed: 12/15/2022] Open
Abstract
Botulinum neurotoxins (BoNTs), the most potent toxins known, are potential bioterrorism agents. It is well established that all seven serotypes of BoNTs (BoNT/A-G) require complex gangliosides as co-receptors. Here, we report that BoNT/DC, a presumed mosaic toxin between BoNT/D and BoNT/C1, binds and enters efficiently into neurons lacking complex gangliosides and shows no reduction in toxicity in mice deficient in complex gangliosides. The co-crystal structure of BoNT/DC with sialyl-Thomsen-Friedenreich antigen (Sialyl-T) suggests that BoNT/DC recognizes only the sialic acid, but not other moieties in gangliosides. Using liposome flotation assays, we demonstrate that an extended loop in BoNT/DC directly interacts with lipid membranes, and the co-occurring sialic acid binding and loop-membrane interactions mediate the recognition of gangliosides in membranes by BoNT/DC. These findings reveal a unique mechanism for cell membrane recognition and demonstrate that BoNT/DC can use a broad range of sialic acid-containing moieties as co-receptors.
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Affiliation(s)
- Sicai Zhang
- Department of Urology, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Department of Microbiology and Immunobiology and Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA
| | - Ronnie P-A Berntsson
- Department of Biochemistry and Biophysics, Stockholm University, SE-106 91, Stockholm, Sweden
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87, Umeå, Sweden
| | - William H Tepp
- Department of Bacteriology, University of Wisconsin, Madison, WI, 53706, USA
| | - Liang Tao
- Department of Urology, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Department of Microbiology and Immunobiology and Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA
| | - Eric A Johnson
- Department of Bacteriology, University of Wisconsin, Madison, WI, 53706, USA
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, SE-106 91, Stockholm, Sweden.
| | - Min Dong
- Department of Urology, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
- Department of Microbiology and Immunobiology and Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA.
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113
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Gustafsson R, Berntsson RPA, Martínez-Carranza M, El Tekle G, Odegrip R, Johnson EA, Stenmark P. Crystal structures of OrfX2 and P47 from a Botulinum neurotoxin OrfX-type gene cluster. FEBS Lett 2017; 591:3781-3792. [PMID: 29067689 DOI: 10.1002/1873-3468.12889] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 10/17/2017] [Accepted: 10/18/2017] [Indexed: 11/08/2022]
Abstract
Botulinum neurotoxins are highly toxic substances and are all encoded together with one of two alternative gene clusters, the HA or the OrfX gene cluster. Very little is known about the function and structure of the proteins encoded in the OrfX gene cluster, which in addition to the toxin contains five proteins (OrfX1, OrfX2, OrfX3, P47, and NTNH). We here present the structures of OrfX2 and P47, solved to 2.1 and 1.8 Å, respectively. We show that they belong to the TULIP protein superfamily, which are often involved in lipid binding. OrfX1 and OrfX2 were both found to bind phosphatidylinositol lipids.
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Affiliation(s)
- Robert Gustafsson
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Ronnie P-A Berntsson
- Department of Biochemistry and Biophysics, Stockholm University, Sweden.,Department of Medical Biochemistry and Biophysics, Umeå University, Sweden
| | | | - Geniver El Tekle
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Richard Odegrip
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Eric A Johnson
- Department of Bacteriology, University of Wisconsin, Madison, WI, USA
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
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114
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Pirazzini M, Azarnia Tehran D, Zanetti G, Rossetto O, Montecucco C. Hsp90 and Thioredoxin-Thioredoxin Reductase enable the catalytic activity of Clostridial neurotoxins inside nerve terminals. Toxicon 2017; 147:32-37. [PMID: 29111118 DOI: 10.1016/j.toxicon.2017.10.028] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 10/21/2017] [Accepted: 10/23/2017] [Indexed: 12/12/2022]
Abstract
Botulinum (BoNTs) and tetanus (TeNT) neurotoxins are the most toxic substances known and form the growing family of Clostridial neurotoxins (CNT), the etiologic agents of botulism and tetanus. CNT are composed of a metalloprotease light chain (L), linked via a disulfide bond to a heavy chain (H). H mediates the binding to nerve terminals and the membrane translocation of L into the cytosol, where its substrates, the three SNARE proteins, are localized. L translocation is accompanied by unfolding and, once delivered on the cytosolic side of the endosome membrane, it has to be reduced and reacquire the native fold to be active. The Thioredoxin-Thioredoxin Reductase system (Trx-TrxR) specifically reduces the interchain disulfide bond while the cytosolic chaperone protein Hsp90 mediates L refolding. Both steps are essential for CNT activity and their inhibition efficiently blocks the neurotoxicity in cultured neurons and mice. Trx and its reductase physically interact with Hsp90 and are loosely bound to the cytosolic side of synaptic vesicles, the organelle exploited by CNT to enter nerve terminals and wherefrom L is translocated into the cytosol. Therefore, Trx, TrxR and Hsp90 orchestrate a chaperone-redox molecular machinery that enables the catalytic activity of the L inside nerve terminals. Given the fundamental role of L reduction and refolding, this machinery represents a rational target for the development of mechanism-based antitoxins.
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Affiliation(s)
- Marco Pirazzini
- Dipartimento di Scienze Biomediche, Università di Padova, Via U. Bassi 58/B, 35121 Padova, Italy.
| | - Domenico Azarnia Tehran
- Dipartimento di Scienze Biomediche, Università di Padova, Via U. Bassi 58/B, 35121 Padova, Italy
| | - Giulia Zanetti
- Dipartimento di Scienze Biomediche, Università di Padova, Via U. Bassi 58/B, 35121 Padova, Italy
| | - Ornella Rossetto
- Dipartimento di Scienze Biomediche, Università di Padova, Via U. Bassi 58/B, 35121 Padova, Italy
| | - Cesare Montecucco
- Dipartimento di Scienze Biomediche, Università di Padova, Via U. Bassi 58/B, 35121 Padova, Italy; Istituto CNR di Neuroscienze, Università di Padova, Via U. Bassi 58/B, 35121 Padova, Italy
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115
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Montecucco C, Zanotti G. Botulinum neurotoxin A1 likes it double sweet. Nat Struct Mol Biol 2017; 23:619-21. [PMID: 27384187 DOI: 10.1038/nsmb.3253] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Cesare Montecucco
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Giuseppe Zanotti
- Department of Biomedical Sciences, University of Padova, Padova, Italy
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116
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Rasetti-Escargueil C, Avril A, Miethe S, Mazuet C, Derman Y, Selby K, Thullier P, Pelat T, Urbain R, Fontayne A, Korkeala H, Sesardic D, Hust M, Popoff MR. The European AntibotABE Framework Program and Its Update: Development of Innovative Botulinum Antibodies. Toxins (Basel) 2017; 9:toxins9100309. [PMID: 28974033 PMCID: PMC5666356 DOI: 10.3390/toxins9100309] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 09/15/2017] [Accepted: 09/16/2017] [Indexed: 02/06/2023] Open
Abstract
The goal of the AntiBotABE Program was the development of recombinant antibodies that neutralize botulinum neurotoxins (BoNT) A, B and E. These serotypes are lethal and responsible for most human botulinum cases. To improve therapeutic efficacy, the heavy and light chains (HC and LC) of the three BoNT serotypes were targeted to achieve a synergistic effect (oligoclonal antibodies). For antibody isolation, macaques were immunized with the recombinant and non-toxic BoNT/A, B or E, HC or LC, followed by the generation of immune phage-display libraries. Antibodies were selected from these libraries against the holotoxin and further analyzed in in vitro and ex vivo assays. For each library, the best ex vivo neutralizing antibody fragments were germline-humanized and expressed as immunoglobulin G (IgGs). The IgGs were tested in vivo, in a standardized model of protection, and challenged with toxins obtained from collections of Clostridium strains. Protective antibody combinations against BoNT/A and BoNT/B were evidenced and for BoNT/E, the anti-LC antibody alone was found highly protective. The combination of these five antibodies as an oligoclonal antibody cocktail can be clinically and regulatorily developed while their high “humanness” predicts a high tolerance in humans.
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Affiliation(s)
| | - Arnaud Avril
- Institut de Recherche Biomédicale des Armées (IRBA-CRSSA), Département de Microbiologie, Unité de Biotechnologie des Anticorps et Des Toxins, Cedex 38702 La Tronche, France.
- Institut de Recherche Biomédicale des Armées (IRBA), Département des Maladies Infectieuses, Unité Biothérapies anti-Infectieuses et Immunité, 1 Place du Général Valérie André, BP73, 91220 Brétigny-sur-Orge, France.
| | - Sebastian Miethe
- Technische Universität Braunschweig, Institut für Biochemie, Biotechnologie und Bioinformatik, Abteilung Biotechnologie, Spielmannstr. 7, 38106 Braunschweig, Germany and YUMAB GmbH, Rebenring 33, Braunschweig 38106, Germany.
| | - Christelle Mazuet
- Institut Pasteur, Unité des Bactéries Anaérobies et Toxines, 25 Avenue du Docteur Roux, 75015 Paris, France.
| | - Yagmur Derman
- Department of Food Hygiene and Environmental Health, University of Helsinki, P.O. Box 66, FI-00014 Helsinki, Finland.
| | - Katja Selby
- Department of Food Hygiene and Environmental Health, University of Helsinki, P.O. Box 66, FI-00014 Helsinki, Finland.
| | - Philippe Thullier
- Institut de Recherche Biomédicale des Armées (IRBA-CRSSA), Département de Microbiologie, Unité de Biotechnologie des Anticorps et Des Toxins, Cedex 38702 La Tronche, France.
| | - Thibaut Pelat
- Institut de Recherche Biomédicale des Armées (IRBA-CRSSA), Département de Microbiologie, Unité de Biotechnologie des Anticorps et Des Toxins, Cedex 38702 La Tronche, France.
- BIOTEM, Parc d'activité Bièvre Dauphine 885, Rue Alphonse Gourju, 38140 Apprieu, France.
| | - Remi Urbain
- LFB Biotechnologies, Therapeutic Innovation Department, 59, Rue de Trévise, BP 2006-59011 Lille Cedex, France.
- Ecdysis Pharma, Bioincubateur Eurasanté, 70 Rue du Dr Yersin, 59120 Loos, France.
| | - Alexandre Fontayne
- LFB Biotechnologies, Therapeutic Innovation Department, 59, Rue de Trévise, BP 2006-59011 Lille Cedex, France.
| | - Hannu Korkeala
- Department of Food Hygiene and Environmental Health, University of Helsinki, P.O. Box 66, FI-00014 Helsinki, Finland.
| | - Dorothea Sesardic
- National Institute for Biological Standards and Control (NIBSC), a Center of the Medicines and Healthcare Products Regulatory Agency, Division of Bacteriology, Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, UK.
| | - Michael Hust
- Technische Universität Braunschweig, Institut für Biochemie, Biotechnologie und Bioinformatik, Abteilung Biotechnologie, Spielmannstr. 7, 38106 Braunschweig, Germany and YUMAB GmbH, Rebenring 33, Braunschweig 38106, Germany.
| | - Michel R Popoff
- Institut Pasteur, Unité des Bactéries Anaérobies et Toxines, 25 Avenue du Docteur Roux, 75015 Paris, France.
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117
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Scheps D, López de la Paz M, Jurk M, Hofmann F, Frevert J. Design of modified botulinum neurotoxin A1 variants with a shorter persistence of paralysis and duration of action. Toxicon 2017; 139:101-108. [PMID: 28918229 DOI: 10.1016/j.toxicon.2017.09.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 08/24/2017] [Accepted: 09/09/2017] [Indexed: 01/08/2023]
Abstract
Botulinum neurotoxins (BoNTs) are classified by their antigenic properties into seven serotypes (A-G) and in addition by their corresponding subtypes. They are further characterized by divergent onset and duration of effect. Injections of low doses of botulinum neurotoxins cause localized muscle paralysis that is beneficial for the treatment of several medical disorders and aesthetic indications. Optimizing the therapeutic properties could offer new treatment opportunities. This report describes a rational design approach to modify the pharmacological properties by mutations in the C-terminus of BoNT/A1 light chain (LC). Toxins with C-terminal modified LC's displayed an altered onset and duration of the paralytic effect in vivo. The level of effect was dependent on the kind of the mutation in the sequence of the C-terminus. A mutant with three mutations (T420E F423M Y426F) revealed a faster onset and a shorter duration than BoNT/A1 wild type (WT). It could be shown that the C-terminus of BoNT/A1-Lc controls both onset and duration of effect. Thus, it is possible to create a mutated BoNT/A1 with different pharmacological properties which might be useful in the therapy of new indications. This strategy opens the way to design BoNT variants with novel and useful properties.
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Affiliation(s)
- Daniel Scheps
- Merz Pharmaceuticals GmbH, Hermannswerder Haus 15, 14473, Potsdam, Germany
| | | | - Marcel Jurk
- Merz Pharmaceuticals GmbH, Hermannswerder Haus 15, 14473, Potsdam, Germany
| | - Fred Hofmann
- Merz Pharmaceuticals GmbH, Hermannswerder Haus 15, 14473, Potsdam, Germany
| | - Jürgen Frevert
- Merz Pharmaceuticals GmbH, Hermannswerder Haus 15, 14473, Potsdam, Germany.
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118
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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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119
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Synaptic vesicle 2C and its synaptic-related function. Clin Chim Acta 2017; 472:112-117. [PMID: 28774501 DOI: 10.1016/j.cca.2017.07.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 07/27/2017] [Accepted: 07/30/2017] [Indexed: 11/22/2022]
Abstract
Synaptic vesicle 2 C (SV2C) is a novel isoform belonging to the synaptic vesicle 2 (SV2) protein superfamily; a family of proteins known to have roles in vesicle trafficking, exocytosis and neurotransmission. In humans, SV2C is expressed in evolutionarily older brain regions, and is a known receptor for botulinum neurotoxin/A (BoNT/A), controlling glucose-evoked granule recruitment and regulating dopamine release, thus serving as a potential target molecule in the treatment of psychosis. In addition, recent researches have shown that SV2C regulates hypertension and accelerates venous thromboembolism (VTE) and coagulation pathways and may play roles in several non-nervous system diseases. In terms of regulation, SV2C is positively regulated by both alendronate and statins. As SV2C may provide a potential novel therapeutic target for psychosis and other diseases, this article reviews the progress made thus far in understanding the structure, distribution, function and regulation of SV2C.
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120
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Identification and characterization of a novel botulinum neurotoxin. Nat Commun 2017; 8:14130. [PMID: 28770820 PMCID: PMC5543303 DOI: 10.1038/ncomms14130] [Citation(s) in RCA: 164] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 12/02/2016] [Indexed: 12/19/2022] Open
Abstract
Botulinum neurotoxins are known to have seven serotypes (BoNT/A-G). Here we report a new BoNT serotype, tentatively named BoNT/X, which has the lowest sequence identity with other BoNTs and is not recognized by antisera against known BoNTs. Similar to BoNT/B/D/F/G, BoNT/X cleaves vesicle-associated membrane proteins (VAMP) 1, 2 and 3, but at a novel site (Arg66-Ala67 in VAMP2). Remarkably, BoNT/X is the only toxin that also cleaves non-canonical substrates VAMP4, VAMP5 and Ykt6. To validate its activity, a small amount of full-length BoNT/X was assembled by linking two non-toxic fragments using a transpeptidase (sortase). Assembled BoNT/X cleaves VAMP2 and VAMP4 in cultured neurons and causes flaccid paralysis in mice. Thus, BoNT/X is a novel BoNT with a unique substrate profile. Its discovery posts a challenge to develop effective countermeasures, provides a novel tool for studying intracellular membrane trafficking, and presents a new potential therapeutic toxin for modulating secretions in cells.
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121
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Masuyer G, Conrad J, Stenmark P. The structure of the tetanus toxin reveals pH-mediated domain dynamics. EMBO Rep 2017; 18:1306-1317. [PMID: 28645943 PMCID: PMC5538627 DOI: 10.15252/embr.201744198] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 05/16/2017] [Accepted: 05/23/2017] [Indexed: 11/09/2022] Open
Abstract
The tetanus neurotoxin (TeNT) is a highly potent toxin produced by Clostridium tetani that inhibits neurotransmission of inhibitory interneurons, causing spastic paralysis in the tetanus disease. TeNT differs from the other clostridial neurotoxins by its unique ability to target the central nervous system by retrograde axonal transport. The crystal structure of the tetanus toxin reveals a "closed" domain arrangement stabilised by two disulphide bridges, and the molecular details of the toxin's interaction with its polysaccharide receptor. An integrative analysis combining X-ray crystallography, solution scattering and single particle electron cryo-microscopy reveals pH-mediated domain rearrangements that may give TeNT the ability to adapt to the multiple environments encountered during intoxication, and facilitate binding to distinct receptors.
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Affiliation(s)
- Geoffrey Masuyer
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Julian Conrad
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
- Science for Life Laboratory, Stockholm University, Solna, Sweden
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
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122
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Montal M. Tetanus neurotoxin: conformational plasticity as an adaptive strategy. EMBO Rep 2017; 18:1268-1270. [PMID: 28701327 DOI: 10.15252/embr.201744500] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Affiliation(s)
- Mauricio Montal
- Section of Neurobiology, University of California, San Diego, La Jolla, CA, USA
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123
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Tao L, Peng L, Berntsson RPA, Liu SM, Park S, Yu F, Boone C, Palan S, Beard M, Chabrier PE, Stenmark P, Krupp J, Dong M. Engineered botulinum neurotoxin B with improved efficacy for targeting human receptors. Nat Commun 2017; 8:53. [PMID: 28674381 PMCID: PMC5495808 DOI: 10.1038/s41467-017-00064-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 04/26/2017] [Indexed: 11/25/2022] Open
Abstract
Botulinum neurotoxin B is a Food and Drug Administration-approved therapeutic toxin. However, it has lower binding affinity toward the human version of its major receptor, synaptotagmin II (h-Syt II), compared to mouse Syt II, because of a residue difference. Increasing the binding affinity to h-Syt II may improve botulinum neurotoxin B’s therapeutic efficacy and reduce adverse effects. Here we utilized the bacterial adenylate cyclase two-hybrid method and carried out a saturation mutagenesis screen in the Syt II-binding pocket of botulinum neurotoxin B. The screen identifies E1191 as a key residue: replacing it with M/C/V/Q enhances botulinum neurotoxin B binding to human synaptotagmin II. Adding S1199Y/W or W1178Q as a secondary mutation further increases binding affinity. Mutant botulinum neurotoxin B containing E1191M/S1199Y exhibits ~11-fold higher efficacy in blocking neurotransmission than wild-type botulinum neurotoxin B in neurons expressing human synaptotagmin II, demonstrating that enhancing receptor binding increases the overall efficacy at functional levels. The engineered botulinum neurotoxin B provides a platform to develop therapeutic toxins with improved efficacy. Humans are less sensitive to the therapeutic effects of botulinum neurotoxin B (BoNT/B) than the animal models it is tested on due to differences between the human and the mouse receptors. Here, the authors engineer BoNT/B to improve its affinity to human receptors and enhance its therapeutic efficacy.
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Affiliation(s)
- Liang Tao
- Department of Urology, Boston Children's Hospital, Department of Microbiology and Immunobiology, Department of Surgery, Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts, 02115, USA
| | - Lisheng Peng
- Department of Urology, Boston Children's Hospital, Department of Microbiology and Immunobiology, Department of Surgery, Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts, 02115, USA.,Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, No. 600 Tianhe Road, Guangzhou, Guangdong, 510630, China
| | - Ronnie P-A Berntsson
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, SE-106 91, Sweden.,Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, SE-901 87, Sweden
| | | | - SunHyun Park
- Department of Urology, Boston Children's Hospital, Department of Microbiology and Immunobiology, Department of Surgery, Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts, 02115, USA.,Division of Predictive Toxicological Research, Predictive model Research Center, Korea Institute of Toxicology, 141 Gajeong-ro, Yuseong-gu, Daejeon, 34114, South Korea
| | - Feifan Yu
- Department of Urology, Boston Children's Hospital, Department of Microbiology and Immunobiology, Department of Surgery, Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts, 02115, USA
| | - Christopher Boone
- Department of Urology, Boston Children's Hospital, Department of Microbiology and Immunobiology, Department of Surgery, Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts, 02115, USA
| | | | | | | | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, SE-106 91, Sweden.
| | - Johannes Krupp
- IPSEN Bioinnovation, Abingdon, OX14 4RY, UK. .,IPSEN Innovation, Les Ulis, 91940, France.
| | - Min Dong
- Department of Urology, Boston Children's Hospital, Department of Microbiology and Immunobiology, Department of Surgery, Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts, 02115, USA.
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124
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Pirazzini M, Rossetto O, Eleopra R, Montecucco C. Botulinum Neurotoxins: Biology, Pharmacology, and Toxicology. Pharmacol Rev 2017; 69:200-235. [PMID: 28356439 PMCID: PMC5394922 DOI: 10.1124/pr.116.012658] [Citation(s) in RCA: 410] [Impact Index Per Article: 58.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The study of botulinum neurotoxins (BoNT) is rapidly progressing in many aspects.
Novel BoNTs are being discovered owing to next generation sequencing, but their
biologic and pharmacological properties remain largely unknown. The molecular
structure of the large protein complexes that the toxin forms with accessory
proteins, which are included in some BoNT type A1 and B1 pharmacological
preparations, have been determined. By far the largest effort has been dedicated to
the testing and validation of BoNTs as therapeutic agents in an ever increasing
number of applications, including pain therapy. BoNT type A1 has been also exploited
in a variety of cosmetic treatments, alone or in combination with other agents, and
this specific market has reached the size of the one dedicated to the treatment of
medical syndromes. The pharmacological properties and mode of action of BoNTs have
shed light on general principles of neuronal transport and protein-protein
interactions and are stimulating basic science studies. Moreover, the wide array of
BoNTs discovered and to be discovered and the production of recombinant BoNTs endowed
with specific properties suggest novel uses in therapeutics with increasing
disease/symptom specifity. These recent developments are reviewed here to provide an
updated picture of the biologic mechanism of action of BoNTs, of their increasing use
in pharmacology and in cosmetics, and of their toxicology.
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Affiliation(s)
- Marco Pirazzini
- Department of Biomedical Sciences, University of Padova, Italy (M.P., O.R., C.M.); Neurologic Department, University-Hospital S. Maria della Misericordia, Udine, Italy (R.E.); and Consiglio Nazionale delle Ricerche, Institute of Neuroscience, University of Padova, Italy (C.M.)
| | - Ornella Rossetto
- Department of Biomedical Sciences, University of Padova, Italy (M.P., O.R., C.M.); Neurologic Department, University-Hospital S. Maria della Misericordia, Udine, Italy (R.E.); and Consiglio Nazionale delle Ricerche, Institute of Neuroscience, University of Padova, Italy (C.M.)
| | - Roberto Eleopra
- Department of Biomedical Sciences, University of Padova, Italy (M.P., O.R., C.M.); Neurologic Department, University-Hospital S. Maria della Misericordia, Udine, Italy (R.E.); and Consiglio Nazionale delle Ricerche, Institute of Neuroscience, University of Padova, Italy (C.M.)
| | - Cesare Montecucco
- Department of Biomedical Sciences, University of Padova, Italy (M.P., O.R., C.M.); Neurologic Department, University-Hospital S. Maria della Misericordia, Udine, Italy (R.E.); and Consiglio Nazionale delle Ricerche, Institute of Neuroscience, University of Padova, Italy (C.M.)
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125
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Burns JR, Lambert GS, Baldwin MR. Insights into the Mechanisms by Which Clostridial Neurotoxins Discriminate between Gangliosides. Biochemistry 2017; 56:2571-2583. [DOI: 10.1021/acs.biochem.6b01246] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Joshua R. Burns
- Department of Molecular Microbiology
and Immunology, University of Missouri School of Medicine, Columbia, Missouri 65212, United States
| | - Gregory S. Lambert
- Department of Molecular Microbiology
and Immunology, University of Missouri School of Medicine, Columbia, Missouri 65212, United States
| | - Michael R. Baldwin
- Department of Molecular Microbiology
and Immunology, University of Missouri School of Medicine, Columbia, Missouri 65212, United States
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Cai BB, Francis J, Brin MF, Broide RS. Botulinum neurotoxin type A-cleaved SNAP25 is confined to primary motor neurons and localized on the plasma membrane following intramuscular toxin injection. Neuroscience 2017; 352:155-169. [PMID: 28389376 DOI: 10.1016/j.neuroscience.2017.03.049] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 03/01/2017] [Accepted: 03/27/2017] [Indexed: 10/19/2022]
Abstract
The mechanism of action of botulinum neurotoxin type A (BoNT/A) is well characterized, but some published evidence suggests the potential for neuronal retrograde transport and cell-to-cell transfer (transcytosis) under certain experimental conditions. The present study evaluated the potential for these processes using a highly selective antibody for the BoNT/A-cleaved substrate (SNAP25197) combined with 3-dimensional imaging. SNAP25197 was characterized in a rat motor neuron (MN) pathway following toxin intramuscular injections at various doses to determine whether SNAP25197 is confined to MNs or also found in neighboring cells or nerve fibers within spinal cord (SC). Results demonstrated that SNAP25197 immuno-reactive staining was colocalized with biomarkers for MNs, but not with markers for neighboring neurons, nerve fibers or glial cells. Additionally, a high dose of BoNT/A, but not a lower dose, resulted in sporadic SNAP25197 signal in distal muscles and associated SC regions without evidence for transcytosis, suggesting that the staining was due to systemic spread of the toxin. Despite this spread, functional effects were not detected in the distal muscles. Therefore, under the present experimental conditions, our results suggest that BoNT/A is confined to MNs and any evidence of distal activity is due to limited systemic spread of the toxin at higher doses and not through transcytosis within SC. Lastly, at higher doses of BoNT/A, SNAP25197 was expressed throughout MNs and colocalized with synaptic markers on the plasma membrane at 6 days post-treatment. These data support previous studies suggesting that SNAP25197 may be incorporated into SNARE-protein complexes within the affected MNs.
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Affiliation(s)
- Brian B Cai
- Department of Biological Sciences, Allergan plc, Irvine, CA 92612, United States
| | - Joseph Francis
- Department of Biological Sciences, Allergan plc, Irvine, CA 92612, United States
| | - Mitchell F Brin
- Department of Biological Sciences, Allergan plc, Irvine, CA 92612, United States; Department of Neurology, University of California, Irvine, CA, 92697, United States
| | - Ron S Broide
- Department of Biological Sciences, Allergan plc, Irvine, CA 92612, United States.
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Pirazzini M, Rossetto O. Challenges in searching for therapeutics against Botulinum Neurotoxins. Expert Opin Drug Discov 2017; 12:497-510. [DOI: 10.1080/17460441.2017.1303476] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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128
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Wang J, Meng J, Nugent M, Tang M, Dolly JO. Neuronal entry and high neurotoxicity of botulinum neurotoxin A require its N-terminal binding sub-domain. Sci Rep 2017; 7:44474. [PMID: 28295026 PMCID: PMC5353748 DOI: 10.1038/srep44474] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 02/09/2017] [Indexed: 01/15/2023] Open
Abstract
Botulinum neurotoxins (BoNTs) are the most toxic proteins known, due to inhibiting the neuronal release of acetylcholine and causing flaccid paralysis. Most BoNT serotypes target neurons by binding to synaptic vesicle proteins and gangliosides via a C-terminal binding sub-domain (HCC). However, the role of their conserved N-terminal sub-domain (HCN) has not been established. Herein, we created a mutant form of recombinant BoNT/A lacking HCN (rAΔHCN) and showed that the lethality of this mutant is reduced 3.3 × 104-fold compared to wild-type BoNT/A. Accordingly, low concentrations of rAΔHCN failed to bind either synaptic vesicle protein 2C or neurons, unlike the high-affinity neuronal binding obtained with 125I-BoNT/A (Kd = 0.46 nM). At a higher concentration, rAΔHCN did bind to cultured sensory neurons and cluster on the surface, even after 24 h exposure. In contrast, BoNT/A became internalised and its light chain appeared associated with the plasmalemma, and partially co-localised with vesicle-associated membrane protein 2 in some vesicular compartments. We further found that a point mutation (W985L) within HCN reduced the toxicity over 10-fold, while this mutant maintained the same level of binding to neurons as wild type BoNT/A, suggesting that HCN makes additional contributions to productive internalization/translocation steps beyond binding to neurons.
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Affiliation(s)
- Jiafu Wang
- International Centre for Neurotherapeutics, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Jianghui Meng
- International Centre for Neurotherapeutics, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Marc Nugent
- International Centre for Neurotherapeutics, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Minhong Tang
- International Centre for Neurotherapeutics, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - J Oliver Dolly
- International Centre for Neurotherapeutics, Dublin City University, Glasnevin, Dublin 9, Ireland
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129
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Yang NJ, Chiu IM. Bacterial Signaling to the Nervous System through Toxins and Metabolites. J Mol Biol 2017; 429:587-605. [PMID: 28065740 PMCID: PMC5325782 DOI: 10.1016/j.jmb.2016.12.023] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 12/21/2016] [Accepted: 12/29/2016] [Indexed: 12/31/2022]
Abstract
Mammalian hosts interface intimately with commensal and pathogenic bacteria. It is increasingly clear that molecular interactions between the nervous system and microbes contribute to health and disease. Both commensal and pathogenic bacteria are capable of producing molecules that act on neurons and affect essential aspects of host physiology. Here we highlight several classes of physiologically important molecular interactions that occur between bacteria and the nervous system. First, clostridial neurotoxins block neurotransmission to or from neurons by targeting the SNARE complex, causing the characteristic paralyses of botulism and tetanus during bacterial infection. Second, peripheral sensory neurons-olfactory chemosensory neurons and nociceptor sensory neurons-detect bacterial toxins, formyl peptides, and lipopolysaccharides through distinct molecular mechanisms to elicit smell and pain. Bacteria also damage the central nervous system through toxins that target the brain during infection. Finally, the gut microbiota produces molecules that act on enteric neurons to influence gastrointestinal motility, and metabolites that stimulate the "gut-brain axis" to alter neural circuits, autonomic function, and higher-order brain function and behavior. Furthering the mechanistic and molecular understanding of how bacteria affect the nervous system may uncover potential strategies for modulating neural function and treating neurological diseases.
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Affiliation(s)
- Nicole J Yang
- Department of Microbiology and Immunobiology, Division of Immunology, Harvard Medical School, Boston, MA 02115, USA
| | - Isaac M Chiu
- Department of Microbiology and Immunobiology, Division of Immunology, Harvard Medical School, Boston, MA 02115, USA.
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130
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Benoit RM, Schärer MA, Wieser MM, Li X, Frey D, Kammerer RA. Crystal structure of the BoNT/A2 receptor-binding domain in complex with the luminal domain of its neuronal receptor SV2C. Sci Rep 2017; 7:43588. [PMID: 28252640 PMCID: PMC5333631 DOI: 10.1038/srep43588] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 01/25/2017] [Indexed: 11/09/2022] Open
Abstract
A detailed molecular understanding of botulinum neurotoxin (BoNT)/host-cell-receptor interactions is fundamental both for developing strategies against botulism and for generating improved BoNT variants for medical applications. The X-ray crystal structure of the receptor-binding domain (HC) of BoNT/A1 in complex with the luminal domain (LD) of its neuronal receptor SV2C revealed only few specific side-chain - side-chain interactions that are important for binding. Notably, two BoNT/A1 residues, Arg 1156 and Arg 1294, that are crucial for the interaction with SV2, are not conserved among subtypes. Because it has been suggested that differential receptor binding of subtypes might explain their differences in biological activity, we determined the crystal structure of BoNT/A2-HC in complex with SV2C-LD. Although only few side-chain interactions are conserved between the two BoNT/A subtypes, the overall binding mode of subtypes A1 and A2 is virtually identical. In the BoNT/A2-HC - SV2C complex structure, a missing cation-π stacking is compensated for by an additional salt bridge and an anion-π stacking interaction, which explains why the binding of BoNT/A subtypes to SV2C tolerates variable side chains. These findings suggest that motif extensions and a shallow binding cleft in BoNT/A-HC contribute to binding specificity.
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Affiliation(s)
- Roger M Benoit
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - Martin A Schärer
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - Mara M Wieser
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - Xiaodan Li
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - Daniel Frey
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - Richard A Kammerer
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
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131
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Jenkinson SP, Grandgirard D, Heidemann M, Tscherter A, Avondet MA, Leib SL. Embryonic Stem Cell-Derived Neurons Grown on Multi-Electrode Arrays as a Novel In vitro Bioassay for the Detection of Clostridium botulinum Neurotoxins. Front Pharmacol 2017; 8:73. [PMID: 28280466 PMCID: PMC5322221 DOI: 10.3389/fphar.2017.00073] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 02/06/2017] [Indexed: 12/01/2022] Open
Abstract
Clostridium botulinum neurotoxins (BoNTs) are the most poisonous naturally occurring protein toxins known to mankind and are the causative agents of the severe and potentially life-threatening disease botulism. They are also known for their application as cosmetics and as unique bio-pharmaceuticals to treat an increasing number of neurological and non-neurological disorders. Currently, the potency of biologically active BoNT for therapeutic use is mainly monitored by the murine LD50-assay, an ethically disputable test causing suffering and death of a considerable number of mice. The aim of this study was to establish an in vitro assay as an alternative to the widely used in vivo mouse bioassay. We report a novel BoNT detection assay using mouse embryonic stem cell-derived neurons (mESN) cultured on multi-electrode arrays (MEAs). After 21 days in culture, the mESN formed a neuronal network showing spontaneous bursting activity based on functional synapses and express the necessary target proteins for BoNTs. Treating cultures for 6 h with 16.6 pM of BoNT serotype A and incubation with 1.66 pM BoNT/A or 33 Units/ml of Botox® for 24 h lead to a significant reduction of both spontaneous network bursts and average spike rate. This data suggests that mESN cultured on MEAs pose a novel, biologically relevant model that can be used to detect and quantify functional BoNT effects, thus accelerating BoNT research while decreasing animal use.
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Affiliation(s)
- Stephen P Jenkinson
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of BernBern, Switzerland; Biology Division, Spiez Laboratory, Swiss Federal Office for Civil ProtectionSpiez, Switzerland; Cluster for Regenerative Neuroscience, Department for Clinical Research, University of BernBern, Switzerland; Graduate School for Cellular and Biomedical Sciences, University of BernBern, Switzerland
| | - Denis Grandgirard
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of BernBern, Switzerland; Cluster for Regenerative Neuroscience, Department for Clinical Research, University of BernBern, Switzerland
| | | | - Anne Tscherter
- Department of Physiology, University of Bern Bern, Switzerland
| | - Marc-André Avondet
- Biology Division, Spiez Laboratory, Swiss Federal Office for Civil Protection Spiez, Switzerland
| | - Stephen L Leib
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of BernBern, Switzerland; Cluster for Regenerative Neuroscience, Department for Clinical Research, University of BernBern, Switzerland
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132
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Vazquez-Cintron EJ, Beske PH, Tenezaca L, Tran BQ, Oyler JM, Glotfelty EJ, Angeles CA, Syngkon A, Mukherjee J, Kalb SR, Band PA, McNutt PM, Shoemaker CB, Ichtchenko K. Engineering Botulinum Neurotoxin C1 as a Molecular Vehicle for Intra-Neuronal Drug Delivery. Sci Rep 2017; 7:42923. [PMID: 28220863 PMCID: PMC5318933 DOI: 10.1038/srep42923] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 01/16/2017] [Indexed: 12/21/2022] Open
Abstract
Botulinum neurotoxin (BoNT) binds to and internalizes its light chain into presynaptic compartments with exquisite specificity. While the native toxin is extremely lethal, bioengineering of BoNT has the potential to eliminate toxicity without disrupting neuron-specific targeting, thereby creating a molecular vehicle capable of delivering therapeutic cargo into the neuronal cytosol. Building upon previous work, we have developed an atoxic derivative (ad) of BoNT/C1 through rationally designed amino acid substitutions in the metalloprotease domain of wild type (wt) BoNT/C1. To test if BoNT/C1 ad retains neuron-specific targeting without concomitant toxic host responses, we evaluated the localization, activity, and toxicity of BoNT/C1 ad in vitro and in vivo. In neuronal cultures, BoNT/C1 ad light chain is rapidly internalized into presynaptic compartments, but does not cleave SNARE proteins nor impair spontaneous neurotransmitter release. In mice, systemic administration resulted in the specific co-localization of BoNT/C1 ad with diaphragmatic motor nerve terminals. The mouse LD50 of BoNT/C1 ad is 5 mg/kg, with transient neurological symptoms emerging at sub-lethal doses. Given the low toxicity and highly specific neuron-targeting properties of BoNT/C1 ad, these data suggest that BoNT/C1 ad can be useful as a molecular vehicle for drug delivery to the neuronal cytoplasm.
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Affiliation(s)
- Edwin J Vazquez-Cintron
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA.,CytoDel LLC, New York, NY, 10027, USA.,The United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Phillip H Beske
- The United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Luis Tenezaca
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA.,CytoDel LLC, New York, NY, 10027, USA
| | - Bao Q Tran
- Excet, Inc., 6225 Brandon Ave., Suite 360, Springfield, VA, 22150, USA
| | - Jonathan M Oyler
- The United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Elliot J Glotfelty
- The United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Christopher A Angeles
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
| | - Aurelia Syngkon
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
| | - Jean Mukherjee
- Department of Infectious Diseases and Global Health, Tufts University Clinical and Translational Science Institute, North Grafton, MA, 01536, USA
| | - Suzanne R Kalb
- Centers for Disease Control and Prevention, National Center for Environmental Health/Agency for Toxic Substances and Disease Registry, Atlanta, GA 30341, USA
| | - Philip A Band
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA.,CytoDel LLC, New York, NY, 10027, USA.,Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, NY, 10016, USA
| | - Patrick M McNutt
- The United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Charles B Shoemaker
- Department of Infectious Diseases and Global Health, Tufts University Clinical and Translational Science Institute, North Grafton, MA, 01536, USA
| | - Konstantin Ichtchenko
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
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133
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Yalamanchili C, Manda VK, Chittiboyina AG, Guernieri RL, Harrell WA, Webb RP, Smith LA, Khan IA. Utilizing Ayurvedic literature for the identification of novel phytochemical inhibitors of botulinum neurotoxin A. JOURNAL OF ETHNOPHARMACOLOGY 2017; 197:211-217. [PMID: 27469199 DOI: 10.1016/j.jep.2016.07.069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 07/20/2016] [Accepted: 07/25/2016] [Indexed: 06/06/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Ayurveda, an ancient holistic system of health care practiced on the Indian subcontinent, utilizes a number of multi-plant formulations and is considered by many as a potential source for novel treatments, as well as the identification of new drugs. Our aim is to identify novel phytochemicals for the inhibition of bacterial exotoxin, botulinum neurotoxin A (BoNT/A) based on Ayurvedic literature. BoNT/A is released by Clostridium species, which when ingested, inhibits the release of acetylcholine by concentrating at the neuromuscular junction and causes flaccid paralysis, resulting in a condition termed as botulism, and may also lead to death due to respiratory arrest. METHODS Fifteen plants were selected from the book 'Diagnosis and treatment of diseases in Ayurveda' by Vaidya Bhagwan Dash and Lalitesh Kashyap, based on their frequency of use in the formulations used for the treatment of six diseases with neuromuscular symptoms similar to botulism. Phytochemicals from these plants were screened using in silico, and in vitro methods. Structures of 570 reported phytochemicals from 14 plants were docked inside six reported BoNT/A light chain crystal structures using ensemble docking module in Maestro (Schrödinger, LLE). RESULTS From the docking scores and structural diversity, nine compounds including acoric acid 1, three flavonoids, three coumarins derivatives, one kava lactone were selected and screened using an in vitro HPLC-based protease assay. The bioassay results showed that several compounds possess BoNT/A LC inhibition of 50-60% when compared to positive controls NSC 84094 and CB7967495 (80-95%). CONCLUSION Further testing of the active compounds identified from Ayurvedic literature and structure-activity studies of acoric acid 1 using more sensitive bioassays is under way. The identification of acoric acid 1, a novel scaffold against BoNT/A, exemplifies the utility of Ayurvedic literature for the discovery of novel drug leads.
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Affiliation(s)
- Chinni Yalamanchili
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, The University of Mississippi, University, MS 38677, USA; Divison of Pharmacognosy, Department of BioMolecular Sciences, The University of Mississippi, University, MS 38677, USA
| | - Vamshi K Manda
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, The University of Mississippi, University, MS 38677, USA
| | - Amar G Chittiboyina
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, The University of Mississippi, University, MS 38677, USA
| | - Rebecca L Guernieri
- US Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702-5011, USA
| | - William A Harrell
- US Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702-5011, USA
| | - Robert P Webb
- US Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702-5011, USA
| | - Leonard A Smith
- US Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702-5011, USA
| | - Ikhlas A Khan
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, The University of Mississippi, University, MS 38677, USA; Divison of Pharmacognosy, Department of BioMolecular Sciences, The University of Mississippi, University, MS 38677, USA.
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134
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Abstract
BiTox attenuated A-nociceptor-mediated mechanosensitivity in rat models of chronic pain. Plasma extravasation and keratinocyte proliferation were also inhibited but C-fiber nociception was not impaired. Local injections of botulinum toxins have been reported to be useful not only for the treatment of peripheral neuropathic pain and migraine but also to cause long-lasting muscle paralysis, a potentially serious side effect. Recently, a botulinum A-based molecule (“BiTox”) has been synthesized that retains neuronal silencing capacity without triggering muscle paralysis. In this study, we examined whether BiTox delivered peripherally was able to reduce or prevent the increased nociceptive sensitivity found in animal models of inflammatory, surgical, and neuropathic pain. Plasma extravasation and edema were also measured as well as keratinocyte proliferation. No motor deficits were seen and acute thermal and mechanical nociceptive thresholds were unimpaired by BiTox injections. We found reduced plasma extravasation and inflammatory edema as well as lower levels of keratinocyte proliferation in cutaneous tissue after local BiTox injection. However, we found no evidence that BiTox was transported to the dorsal root ganglia or dorsal horn and no deficits in formalin-elicited behaviors or capsaicin or formalin-induced c-Fos expression within the dorsal horn. In contrast, Bitox treatment strongly reduced A-nociceptor-mediated secondary mechanical hyperalgesia associated with either complete Freund’s adjuvant (CFA)-induced joint inflammation or capsaicin injection and the hypersensitivity associated with spared nerve injury. These results imply that although local release of neuromodulators from C-fibers was inhibited by BiTox injection, C-nociceptive signaling function was not impaired. Taken together with recent clinical data the results suggest that BiTox should be considered for treatment of pain conditions in which A-nociceptors are thought to play a significant role.
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135
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Aredo JV, Heyrana KJ, Karp BI, Shah JP, Stratton P. Relating Chronic Pelvic Pain and Endometriosis to Signs of Sensitization and Myofascial Pain and Dysfunction. Semin Reprod Med 2017; 35:88-97. [PMID: 28049214 DOI: 10.1055/s-0036-1597123] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Chronic pelvic pain is a frustrating symptom for patients with endometriosis and is frequently refractory to hormonal and surgical management. While these therapies target ectopic endometrial lesions, they do not directly address pain due to central sensitization of the nervous system and myofascial dysfunction, which can continue to generate pain from myofascial trigger points even after traditional treatments are optimized. This article provides a background for understanding how endometriosis facilitates remodeling of neural networks, contributing to sensitization and generation of myofascial trigger points. A framework for evaluating such sensitization and myofascial trigger points in a clinical setting is presented. Treatments that specifically address myofascial pain secondary to spontaneously painful myofascial trigger points and their putative mechanisms of action are also reviewed, including physical therapy, dry needling, anesthetic injections, and botulinum toxin injections.
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Affiliation(s)
- Jacqueline V Aredo
- National Institute of Neurological Disorders and Stroke, Clinical Center, Intramural Research Program NIH, Bethesda, Maryland
| | - Katrina J Heyrana
- Department of Obstetrics and Gynecology, University of Rochester Medical Center, Rochester, New York
| | - Barbara I Karp
- National Institute of Neurological Disorders and Stroke, Clinical Center, Intramural Research Program NIH, Bethesda, Maryland
| | - Jay P Shah
- Rehabilitation Medicine Department, Clinical Center, Intramural Research Program NIH, Bethesda, Maryland
| | - Pamela Stratton
- National Institute of Neurological Disorders and Stroke, Clinical Center, Intramural Research Program NIH, Bethesda, Maryland
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136
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Connan C, Popoff MR. Uptake of Clostridial Neurotoxins into Cells and Dissemination. Curr Top Microbiol Immunol 2017; 406:39-78. [PMID: 28879524 DOI: 10.1007/82_2017_50] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Clostridial neurotoxins, botulinum neurotoxins (BoNT) and tetanus neurotoxin (TeNT), are potent toxins, which are responsible for severe neurological diseases in man and animals. BoNTs induce a flaccid paralysis (botulism) by inhibiting acetylcholine release at the neuromuscular junctions, whereas TeNT causes a spastic paralysis (tetanus) by blocking the neurotransmitter release (glycine, GABA) in inhibitory interneurons within the central nervous system. Clostridial neurotoxins recognize specific receptor(s) on the target neuronal cells and enter via a receptor-mediated endocytosis. They transit through an acidic compartment which allows the translocation of the catalytic chain into the cytosol, a prerequisite step for the intracellular activity of the neurotoxins. TeNT migrates to the central nervous system by using a motor neuron as transport cell. TeNT enters a neutral pH compartment and undergoes a retrograde axonal transport to the spinal cord or brain, where the whole undissociated toxin is delivered and interacts with target neurons. Botulism most often results from ingestion of food contaminated with BoNT. Thus, BoNT passes through the intestinal epithelial barrier mainly via a transcytotic mechanism and then diffuses or is transported to the neuromuscular junctions by the lymph or blood circulation. Indeed, clostridial neurotoxins are specific neurotoxins which transit through a transport cell to gain access to the target neuron, and use distinct trafficking pathways in both cell types.
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Affiliation(s)
- Chloé Connan
- Unité Des Bactéries Anaérobies et Toxines, Institut Pasteur, 25 Rue Du Dr Roux, 75724, Paris Cedex 15, France
| | - Michel R Popoff
- Unité Des Bactéries Anaérobies et Toxines, Institut Pasteur, 25 Rue Du Dr Roux, 75724, Paris Cedex 15, France.
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137
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Hamark C, Berntsson RPA, Masuyer G, Henriksson LM, Gustafsson R, Stenmark P, Widmalm G. Glycans Confer Specificity to the Recognition of Ganglioside Receptors by Botulinum Neurotoxin A. J Am Chem Soc 2016; 139:218-230. [PMID: 27958736 DOI: 10.1021/jacs.6b09534] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The highly poisonous botulinum neurotoxins, produced by the bacterium Clostridium botulinum, act on their hosts by a high-affinity association to two receptors on neuronal cell surfaces as the first step of invasion. The glycan motifs of gangliosides serve as initial coreceptors for these protein complexes, whereby a membrane protein receptor is bound. Herein we set out to characterize the carbohydrate minimal binding epitope of the botulinum neurotoxin serotype A. By means of ligand-based NMR spectroscopy, X-ray crystallography, computer simulations, and isothermal titration calorimetry, a screening of ganglioside analogues together with a detailed characterization of various carbohydrate ligand complexes with the toxin were accomplished. We show that the representation of the glycan epitope to the protein affects the details of binding. Notably, both branches of the oligosaccharide GD1a can associate to botulinum neurotoxin serotype A when expressed as individual trisaccharides. It is, however, the terminal branch of GD1a as well as this trisaccharide motif alone, corresponding to the sialyl-Thomsen-Friedenreich antigen, that represents the active ligand epitope, and these compounds bind to the neurotoxin with a high degree of predisposition but with low affinities. This finding does not correlate with the oligosaccharide moieties having a strong contribution to the total affinity, which was expected to be the case. We here propose that the glycan part of the ganglioside receptors mainly provides abundance and specificity, whereas the interaction with the membrane itself and protein receptor brings about the strong total binding of the toxin to the neuronal membrane.
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Affiliation(s)
- Christoffer Hamark
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University , S-106 91 Stockholm, Sweden
| | - Ronnie P-A Berntsson
- Department of Biochemistry and Biophysics, Arrhenius Laboratory, Stockholm University , S-106 91 Stockholm, Sweden
| | - Geoffrey Masuyer
- Department of Biochemistry and Biophysics, Arrhenius Laboratory, Stockholm University , S-106 91 Stockholm, Sweden
| | - Linda M Henriksson
- Department of Biochemistry and Biophysics, Arrhenius Laboratory, Stockholm University , S-106 91 Stockholm, Sweden
| | - Robert Gustafsson
- Department of Biochemistry and Biophysics, Arrhenius Laboratory, Stockholm University , S-106 91 Stockholm, Sweden
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Arrhenius Laboratory, Stockholm University , S-106 91 Stockholm, Sweden
| | - Göran Widmalm
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University , S-106 91 Stockholm, Sweden
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138
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Vagin O, Beenhouwer DO. Septins: Regulators of Protein Stability. Front Cell Dev Biol 2016; 4:143. [PMID: 28066764 PMCID: PMC5168428 DOI: 10.3389/fcell.2016.00143] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 12/02/2016] [Indexed: 12/31/2022] Open
Abstract
Septins are small GTPases that play a role in several important cellular processes. In this review, we focus on the roles of septins in protein stabilization. Septins may regulate protein stability by: (1) interacting with proteins involved in degradation pathways, (2) regulating the interaction between transmembrane proteins and cytoskeletal proteins, (3) affecting the mobility of transmembrane proteins in lipid bilayers, and (4) modulating the interaction of proteins with their adaptor or signaling proteins. In this context, we discuss the role of septins in protecting four different proteins from degradation. First we consider botulinum neurotoxin serotype A (BoNT/A) and the contribution of septins to its extraordinarily long intracellular persistence. Next, we discuss the role of septins in stabilizing the receptor tyrosine kinases EGFR and ErbB2. Finally, we consider the contribution of septins in protecting hypoxia-inducible factor 1α (HIF-1α) from degradation.
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Affiliation(s)
- Olga Vagin
- Department of Physiology, Geffen School of Medicine at UCLALos Angeles, CA, USA; VA Greater Los Angeles Healthcare SystemLos Angeles, CA, USA
| | - David O Beenhouwer
- Department of Medicine, Geffen School of Medicine at UCLALos Angeles, CA, USA; Division of Infectious Diseases, VA Greater Los Angeles Health Care SystemLos Angeles, CA, USA
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139
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Matte C, Descoteaux A. Exploitation of the Host Cell Membrane Fusion Machinery by Leishmania Is Part of the Infection Process. PLoS Pathog 2016; 12:e1005962. [PMID: 27930749 PMCID: PMC5145244 DOI: 10.1371/journal.ppat.1005962] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- Christine Matte
- INRS-Institut Armand-Frappier and Centre for host-parasite interactions, Laval, Quebec, Canada
| | - Albert Descoteaux
- INRS-Institut Armand-Frappier and Centre for host-parasite interactions, Laval, Quebec, Canada
- * E-mail:
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140
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Ovsepian SV, O'Leary VB, Ntziachristos V, Dolly JO. Circumventing Brain Barriers: Nanovehicles for Retroaxonal Therapeutic Delivery. Trends Mol Med 2016; 22:983-993. [PMID: 27720365 DOI: 10.1016/j.molmed.2016.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 09/09/2016] [Accepted: 09/12/2016] [Indexed: 02/06/2023]
Abstract
In addition to safeguarding the central nervous system (CNS) from the vast majority of pathogens and toxins, transvascular barriers impose immense challenges to the delivery of beneficial cargo. A few toxins and neurotropic viruses capable of penetrating the brain have proved to be potentially valuable for neuron targeting and enhanced transfer of restorative medicine and therapeutic genes. Here we review molecular concepts and implications of the highly neurotropic tetanus toxin (TeTx) and botulinum neurotoxins (BoNTs) and their ability to infiltrate and migrate throughout neurons. We discuss recent applications of their detoxified variants as versatile nanovehicles for retroaxonal delivery of therapeutics to motor neurons and synapses. Continued advances in research on these remarkable agents in preclinical trials might facilitate their future use for medical benefit.
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Affiliation(s)
- Saak V Ovsepian
- Institute for Biological and Medical Imaging, Helmholtz Zentrum Munich, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany; Munich School of Bioengineering, Technical University Munich, 81675 Munich, Germany; International Centre for Neurotherapeutics, Dublin City University, Dublin 9, Ireland.
| | - Valerie B O'Leary
- Institute of Radiation Biology, Helmholtz Zentrum Munich, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
| | - Vasilis Ntziachristos
- Institute for Biological and Medical Imaging, Helmholtz Zentrum Munich, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany; Munich School of Bioengineering, Technical University Munich, 81675 Munich, Germany
| | - J Oliver Dolly
- International Centre for Neurotherapeutics, Dublin City University, Dublin 9, Ireland
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141
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Oliván S, Calvo AC, Rando A, Herrando-Grabulosa M, Manzano R, Zaragoza P, Tizzano EF, Aquilera J, Osta R. Neuroprotective Effect of Non-viral Gene Therapy Treatment Based on Tetanus Toxin C-fragment in a Severe Mouse Model of Spinal Muscular Atrophy. Front Mol Neurosci 2016; 9:76. [PMID: 27605908 PMCID: PMC4995219 DOI: 10.3389/fnmol.2016.00076] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 08/10/2016] [Indexed: 11/16/2022] Open
Abstract
Spinal muscular atrophy (SMA) is a hereditary childhood disease that causes paralysis and progressive degeneration of skeletal muscles and spinal motor neurons. SMA is associated with reduced levels of full-length Survival of Motor Neuron (SMN) protein, due to mutations in the Survival of Motor Neuron 1 gene. Nowadays there are no effective therapies available to treat patients with SMA, so our aim was to test whether the non-toxic carboxy-terminal fragment of tetanus toxin heavy chain (TTC), which exhibits neurotrophic properties, might have a therapeutic role or benefit in SMA. In this manuscript, we have demonstrated that TTC enhance the SMN expression in motor neurons “in vitro” and evaluated the effect of intramuscular injection of TTC-encoding plasmid in the spinal cord and the skeletal muscle of SMNdelta7 mice. For this purpose, we studied the weight and the survival time, as well as, the survival and cell death pathways and muscular atrophy. Our results showed that TTC treatment reduced the expression of autophagy markers (Becn1, Atg5, Lc3, and p62) and pro-apoptotic genes such as Bax and Casp3 in spinal cord. In skeletal muscle, TTC was able to downregulate the expression of the main marker of autophagy, Lc3, to wild-type levels and the expression of the apoptosis effector protein, Casp3. Regarding the genes related to muscular atrophy (Ankrd1, Calm1, Col19a1, Fbox32, Mt2, Myod1, NogoA, Pax7, Rrad, and Sln), TTC suggest a compensatory effect for muscle damage response, diminished oxidative stress and modulated calcium homeostasis. These preliminary findings suggest the need for further experiments to depth study the effect of TTC in SMA disease.
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Affiliation(s)
- Sara Oliván
- Laboratorio de Genética Bioquímica, Facultad de Veterinaria, Instituto Agroalimentario de Aragón (IA2), Centro de Investigación y Tecnología Agroalimentaria de Aragón, Instituto de Investigación Sanitaria Aragón, Universidad de ZaragozaZaragoza, Spain; Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina, Grupo AMB, Instituto de Investigación en Ingeniería de Aragón (I3A), Universidad de ZaragozaZaragoza, Spain
| | - Ana C Calvo
- Laboratorio de Genética Bioquímica, Facultad de Veterinaria, Instituto Agroalimentario de Aragón (IA2), Centro de Investigación y Tecnología Agroalimentaria de Aragón, Instituto de Investigación Sanitaria Aragón, Universidad de Zaragoza Zaragoza, Spain
| | - Amaya Rando
- Laboratorio de Genética Bioquímica, Facultad de Veterinaria, Instituto Agroalimentario de Aragón (IA2), Centro de Investigación y Tecnología Agroalimentaria de Aragón, Instituto de Investigación Sanitaria Aragón, Universidad de Zaragoza Zaragoza, Spain
| | - Mireia Herrando-Grabulosa
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Spain Institut de Neurociències and Departament de Bioquímica i de Biologia Molecular, Facultat de Medicina, Universitat Autònoma de Barcelona Cerdanyola del Vallès, Spain
| | - Raquel Manzano
- Department of Physiology, Anatomy and Genetics, University of Oxford Oxford, UK
| | - Pilar Zaragoza
- Laboratorio de Genética Bioquímica, Facultad de Veterinaria, Instituto Agroalimentario de Aragón (IA2), Centro de Investigación y Tecnología Agroalimentaria de Aragón, Instituto de Investigación Sanitaria Aragón, Universidad de Zaragoza Zaragoza, Spain
| | - Eduardo F Tizzano
- Área de Genética Clínica y Molecular, Hospital Vall d'Hebron, Centros de Investigación Biomédica en Red Barcelona, Spain
| | - Jose Aquilera
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Spain Institut de Neurociències and Departament de Bioquímica i de Biologia Molecular, Facultat de Medicina, Universitat Autònoma de Barcelona Cerdanyola del Vallès, Spain
| | - Rosario Osta
- Laboratorio de Genética Bioquímica, Facultad de Veterinaria, Instituto Agroalimentario de Aragón (IA2), Centro de Investigación y Tecnología Agroalimentaria de Aragón, Instituto de Investigación Sanitaria Aragón, Universidad de Zaragoza Zaragoza, Spain
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142
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Neurotoxins from Clostridium botulinum (serotype A) isolated from the soil of Mendoza (Argentina) differ from the A-Hall archetype and from that causing infant botulism. Toxicon 2016; 121:30-35. [PMID: 27527271 DOI: 10.1016/j.toxicon.2016.08.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 08/10/2016] [Accepted: 08/11/2016] [Indexed: 11/22/2022]
Abstract
The type A of neurotoxin produced by Clostridium botulinum is the prevalent serotype in strains of Mendoza. The soil is the main reservoir for C.botulinum and is possibly one of the infection sources in infant botulism. In this study, we characterized and compared autochthonous C. botulinum strains and their neurotoxins. Bacterial samples were obtained from the soil and from fecal samples collected from children with infant botulism. We first observed differences in the appearance of the colonies between strains from each source and with the A Hall control strain. In addition, purified neurotoxins of both strains were found to be enriched in a band of 300 kDa, whereas the A-Hall strain was mainly made up of a band of ∼600 kDa. This finding is in line with the lack of hemagglutinating activity of the neurotoxins under study. Moreover, the proteolytic activity of C. botulinum neurotoxins was evaluated against SNARE (soluble N-ethylmaleimide-sensitive factor-attachment protein receptor) proteins from rat brain. It was observed that both, SNAP 25 (synaptosomal-associated protein 25) and VAMP 2 (vesicle-associated membrane protein) were cleaved by the neurotoxins isolated from the soil strains, whereas the neurotoxins from infant botulism strains only induced a partial cleavage of VAMP 2. On the other hand, the neurotoxin from the A-Hall strain was able to cleave both proteins, though at a lesser extent. Our data indicate that the C.botulinum strain isolated from the soil, and its BoNT, exhibit different properties compared to the strain obtained from infant botulism patients, and from the A-Hall archetype.
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143
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Bompiani KM, Caglič D, Krutein MC, Benoni G, Hrones M, Lairson LL, Bian H, Smith GR, Dickerson TJ. High-Throughput Screening Uncovers Novel Botulinum Neurotoxin Inhibitor Chemotypes. ACS COMBINATORIAL SCIENCE 2016; 18:461-74. [PMID: 27314875 DOI: 10.1021/acscombsci.6b00033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Botulism is caused by potent and specific bacterial neurotoxins that infect host neurons and block neurotransmitter release. Treatment for botulism is limited to administration of an antitoxin within a short time window, before the toxin enters neurons. Alternatively, current botulism drug development targets the toxin light chain, which is a zinc-dependent metalloprotease that is delivered into neurons and mediates long-term pathology. Several groups have identified inhibitory small molecules, peptides, or aptamers, although no molecule has advanced to the clinic due to a lack of efficacy in advanced models. Here we used a homogeneous high-throughput enzyme assay to screen three libraries of drug-like small molecules for new chemotypes that modulate recombinant botulinum neurotoxin light chain activity. High-throughput screening of 97088 compounds identified numerous small molecules that activate or inhibit metalloprotease activity. We describe four major classes of inhibitory compounds identified, detail their structure-activity relationships, and assess their relative inhibitory potency. A previously unreported chemotype in any context of enzyme inhibition is described with potent submicromolar inhibition (Ki = 200-300 nM). Additional detailed kinetic analyses and cellular cytotoxicity assays indicate the best compound from this series is a competitive inhibitor with cytotoxicity values around 4-5 μM. Given the potency and drug-like character of these lead compounds, further studies, including cellular activity assays and DMPK analysis, are justified.
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Affiliation(s)
- Kristin M. Bompiani
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Dejan Caglič
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Michelle C. Krutein
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Galit Benoni
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Morgan Hrones
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Luke L. Lairson
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Haiyan Bian
- Fox Chase Chemical Diversity Center, 3805 Old Easton Road, Doylestown, Pennsylvania 18902, United States
| | - Garry R. Smith
- Fox Chase Chemical Diversity Center, 3805 Old Easton Road, Doylestown, Pennsylvania 18902, United States
| | - Tobin J. Dickerson
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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144
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Bomba-Warczak E, Vevea JD, Brittain JM, Figueroa-Bernier A, Tepp WH, Johnson EA, Yeh FL, Chapman ER. Interneuronal Transfer and Distal Action of Tetanus Toxin and Botulinum Neurotoxins A and D in Central Neurons. Cell Rep 2016; 16:1974-87. [PMID: 27498860 DOI: 10.1016/j.celrep.2016.06.104] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 06/07/2016] [Accepted: 07/13/2016] [Indexed: 10/21/2022] Open
Abstract
Recent reports suggest that botulinum neurotoxin (BoNT) A, which is widely used clinically to inhibit neurotransmission, can spread within networks of neurons to have distal effects, but this remains controversial. Moreover, it is not known whether other members of this toxin family are transferred between neurons. Here, we investigate the potential distal effects of BoNT/A, BoNT/D, and tetanus toxin (TeNT), using central neurons grown in microfluidic devices. Toxins acted upon the neurons that mediated initial entry, but all three toxins were also taken up, via an alternative pathway, into non-acidified organelles that mediated retrograde transport to the somato-dendritic compartment. Toxins were then released into the media, where they entered and exerted their effects upon upstream neurons. These findings directly demonstrate that these agents undergo transcytosis and interneuronal transfer in an active form, resulting in long-distance effects.
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Affiliation(s)
- Ewa Bomba-Warczak
- Howard Hughes Medical Institute and Department of Neuroscience, University of Wisconsin, Madison, WI 53705, USA
| | - Jason D Vevea
- Howard Hughes Medical Institute and Department of Neuroscience, University of Wisconsin, Madison, WI 53705, USA
| | - Joel M Brittain
- Howard Hughes Medical Institute and Department of Neuroscience, University of Wisconsin, Madison, WI 53705, USA
| | - Annette Figueroa-Bernier
- Howard Hughes Medical Institute and Department of Neuroscience, University of Wisconsin, Madison, WI 53705, USA
| | - William H Tepp
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706, USA
| | - Eric A Johnson
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706, USA
| | - Felix L Yeh
- Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA
| | - Edwin R Chapman
- Howard Hughes Medical Institute and Department of Neuroscience, University of Wisconsin, Madison, WI 53705, USA.
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145
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Azarnia Tehran D, Pirazzini M, Leka O, Mattarei A, Lista F, Binz T, Rossetto O, Montecucco C. Hsp90 is involved in the entry of clostridial neurotoxins into the cytosol of nerve terminals. Cell Microbiol 2016; 19. [DOI: 10.1111/cmi.12647] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 07/06/2016] [Accepted: 07/08/2016] [Indexed: 12/31/2022]
Affiliation(s)
- Domenico Azarnia Tehran
- Department of Biomedical Sciences; University of Padova; Via Ugo Bassi 58/B 35121 Padova Italy
| | - Marco Pirazzini
- Department of Biomedical Sciences; University of Padova; Via Ugo Bassi 58/B 35121 Padova Italy
| | - Oneda Leka
- Department of Biomedical Sciences; University of Padova; Via Ugo Bassi 58/B 35121 Padova Italy
| | - Andrea Mattarei
- Department of Chemical Sciences; University of Padova; Via F. Marzolo 1 35131 Padova Italy
| | - Florigio Lista
- Histology and Molecular Biology Section; Army Medical and Veterinary Research Center; Via Santo Stefano Rotondo 4 00184 Rome Italy
| | - Thomas Binz
- Medizinische Hochschule Hannover; Institut für Physiologische Chemie OE4310; 30625 Hannover Germany
| | - Ornella Rossetto
- Department of Biomedical Sciences; University of Padova; Via Ugo Bassi 58/B 35121 Padova Italy
| | - Cesare Montecucco
- Department of Biomedical Sciences; University of Padova; Via Ugo Bassi 58/B 35121 Padova Italy
- National Research Institute of Neuroscience; University of Padova; Via Ugo Bassi 58/B 35121 Padova Italy
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146
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Zornetta I, Azarnia Tehran D, Arrigoni G, Anniballi F, Bano L, Leka O, Zanotti G, Binz T, Montecucco C. The first non Clostridial botulinum-like toxin cleaves VAMP within the juxtamembrane domain. Sci Rep 2016; 6:30257. [PMID: 27443638 PMCID: PMC4957215 DOI: 10.1038/srep30257] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 07/01/2016] [Indexed: 12/03/2022] Open
Abstract
The genome of Weissella oryzae SG25T was recently sequenced and a botulinum neurotoxin (BoNT) like gene was identified by bioinformatics methods. The typical three-domains organization of BoNTs with a N-terminal metalloprotease domain, a translocation and a cell binding domains could be identified. The BoNT family of neurotoxins is rapidly growing, but this was the first indication of the possible expression of a BoNT toxin outside the Clostridium genus. We performed molecular modeling and dynamics simulations showing that the 50 kDa N-terminal domain folds very similarly to the metalloprotease domain of BoNT/B, whilst the binding part is different. However, neither the recombinant metalloprotease nor the binding domains showed cross-reactivity with the standard antisera that define the seven serotypes of BoNTs. We found that the purified Weissella metalloprotease cleaves VAMP at a single site untouched by the other VAMP-specific BoNTs. This site is a unique Trp-Trp peptide bond located within the juxtamembrane segment of VAMP which is essential for neurotransmitter release. Therefore, the present study identifies the first non-Clostridial BoNT-like metalloprotease that cleaves VAMP at a novel and relevant site and we propose to label it BoNT/Wo.
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Affiliation(s)
- Irene Zornetta
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, Padova, Italy
| | | | - Giorgio Arrigoni
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, Padova, Italy
- Proteomics Center, University of Padova and Azienda Ospedaliera di Padova, Padova, Italy
| | - Fabrizio Anniballi
- National Reference Center for Botulism, Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità (ISS), Roma, Italy
| | - Luca Bano
- Microbiology and Diagnostic Laboratory, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Vicolo Mazzini 4, Villorba di Treviso, Italy
| | - Oneda Leka
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, Padova, Italy
| | - Giuseppe Zanotti
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, Padova, Italy
| | - Thomas Binz
- Medizinische Hochschule Hannover, Institut für Physiologische Chemie OE4310, Hannover, Germany
| | - Cesare Montecucco
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, Padova, Italy
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147
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Williams JM, Tsai B. Intracellular trafficking of bacterial toxins. Curr Opin Cell Biol 2016; 41:51-6. [PMID: 27084982 DOI: 10.1016/j.ceb.2016.03.019] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 03/23/2016] [Accepted: 03/24/2016] [Indexed: 11/18/2022]
Abstract
Bacterial toxins often translocate across a cellular membrane to gain access into the host cytosol, modifying cellular components in order to exert their toxic effects. To accomplish this feat, these toxins traffic to a membrane penetration site where they undergo conformational changes essential to eject the toxin's catalytic subunit into the cytosol. In this brief review, we highlight recent findings that elucidate both the trafficking pathways and membrane translocation mechanisms of toxins that cross the plasma, endosomal, or endoplasmic reticulum (ER) membrane. These findings not only illuminate the specific nature of the host-toxin interactions during entry, but should also provide additional therapeutic strategies to prevent or alleviate the bacterial toxin-induced diseases.
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Affiliation(s)
- Jeffrey M Williams
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Room 3043, Ann Arbor, MI 48109, United States
| | - Billy Tsai
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Room 3043, Ann Arbor, MI 48109, United States.
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148
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Araye A, Goudet A, Barbier J, Pichard S, Baron B, England P, Pérez J, Zinn-Justin S, Chenal A, Gillet D. The Translocation Domain of Botulinum Neurotoxin A Moderates the Propensity of the Catalytic Domain to Interact with Membranes at Acidic pH. PLoS One 2016; 11:e0153401. [PMID: 27070312 PMCID: PMC4829238 DOI: 10.1371/journal.pone.0153401] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 03/29/2016] [Indexed: 01/23/2023] Open
Abstract
Botulinum neurotoxin A (BoNT/A) is composed of three domains: a catalytic domain (LC), a translocation domain (HN) and a receptor-binding domain (HC). Like most bacterial toxins BoNT/A is an amphitropic protein, produced in a soluble form that is able to interact, penetrate and/or cross a membrane to achieve its toxic function. During intoxication BoNT/A is internalized by the cell by receptor-mediated endocytosis. Then, LC crosses the membrane of the endocytic compartment and reaches the cytosol. This translocation is initiated by the low pH found in this compartment. It has been suggested that LC passes in an unfolded state through a transmembrane passage formed by HN. We report here that acidification induces no major conformational change in either secondary or tertiary structures of LC and HN of BoNT/A in solution. GdnHCl-induced denaturation experiments showed that the stability of LC and HN increases as pH drops, and that HN further stabilizes LC. Unexpectedly we found that LC has a high propensity to interact with and permeabilize anionic lipid bilayers upon acidification without the help of HN. This property is downplayed when LC is linked to HN. HN thus acts as a chaperone for LC by enhancing its stability but also as a moderator of the membrane interaction of LC.
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Affiliation(s)
- Anne Araye
- CEA, iBiTec-S/SIMOPRO, CEA-Saclay, Paris Saclay University, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
| | - Amélie Goudet
- CEA, iBiTec-S/SIMOPRO, CEA-Saclay, Paris Saclay University, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
| | - Julien Barbier
- CEA, iBiTec-S/SIMOPRO, CEA-Saclay, Paris Saclay University, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
| | - Sylvain Pichard
- CEA, iBiTec-S/SIMOPRO, CEA-Saclay, Paris Saclay University, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
| | - Bruno Baron
- Institut Pasteur, Proteopole, Plateforme de Biophysique des Macromolécules et de leurs Interactions (PFBMI), 25–28 rue du Dr Roux, F-75724 Paris cedex 15, France
| | - Patrick England
- Institut Pasteur, Proteopole, Plateforme de Biophysique des Macromolécules et de leurs Interactions (PFBMI), 25–28 rue du Dr Roux, F-75724 Paris cedex 15, France
| | - Javier Pérez
- Synchrotron Soleil, BP 48, F-91192 Gif-sur-Yvette Cedex, France
| | | | - Alexandre Chenal
- Institut Pasteur, Unité de Biochimie des Interactions Macromoléculaires, UMR 3528, 25–28 rue du Dr Roux, F-75724 Paris cedex 15, France
| | - Daniel Gillet
- CEA, iBiTec-S/SIMOPRO, CEA-Saclay, Paris Saclay University, LabEx LERMIT, F-91191 Gif-sur-Yvette, France
- * E-mail:
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149
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Azarnia Tehran D, Zanetti G, Leka O, Lista F, Fillo S, Binz T, Shone CC, Rossetto O, Montecucco C, Paradisi C, Mattarei A, Pirazzini M. A Novel Inhibitor Prevents the Peripheral Neuroparalysis of Botulinum Neurotoxins. Sci Rep 2015; 5:17513. [PMID: 26670952 PMCID: PMC4680858 DOI: 10.1038/srep17513] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 10/30/2015] [Indexed: 11/17/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) form a large class of potent and deadly neurotoxins. Given their growing number, it is of paramount importance to discover novel inhibitors targeting common steps of their intoxication process. Recently, EGA was shown to inhibit the action of bacterial toxins and viruses exhibiting a pH-dependent translocation step in mammalian cells, by interfering with their entry route. As BoNTs act in the cytosol of nerve terminals, the entry into an appropriate compartment wherefrom they translocate the catalytic moiety is essential for toxicity. Herein we propose an optimized procedure to synthesize EGA and we show that, in vitro, it prevents the neurotoxicity of different BoNT serotypes by interfering with their trafficking. Furthermore, in mice, EGA mitigates botulism symptoms induced by BoNT/A and significantly decreases the lethality of BoNT/B and BoNT/D. This opens the possibility of using EGA as a lead compound to develop novel inhibitors of botulinum neurotoxins.
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Affiliation(s)
| | - Giulia Zanetti
- Department of Biomedical Sciences, Via U. Bassi 58/B, 35121, Padova, Italy
| | - Oneda Leka
- Department of Biomedical Sciences, Via U. Bassi 58/B, 35121, Padova, Italy
| | - Florigio Lista
- Histology and Molecular Biology Section, Army Medical and Veterinary Research Center, Via Santo Stefano Rotondo 4, 00184 Roma, Italy
| | - Silvia Fillo
- Histology and Molecular Biology Section, Army Medical and Veterinary Research Center, Via Santo Stefano Rotondo 4, 00184 Roma, Italy
| | - Thomas Binz
- Institut für Biochemie, OE 4310, Medizinische Hochschule Hannover, 30623 Hannover, Germany
| | - Clifford C. Shone
- Public Health England, Porton Down, Salisbury, Wiltshire, SP4 OJG, UK
| | - Ornella Rossetto
- Department of Biomedical Sciences, Via U. Bassi 58/B, 35121, Padova, Italy
| | - Cesare Montecucco
- Department of Biomedical Sciences, Via U. Bassi 58/B, 35121, Padova, Italy
- Italian National Research Council Institute of Neuroscience, University of Padova, Via U. Bassi 58/B, 35121, Padova, Italy
| | - Cristina Paradisi
- Department of Chemical Sciences, University of Padova, Via F. Marzolo 1, 35131 Padova, Italy
| | - Andrea Mattarei
- Department of Chemical Sciences, University of Padova, Via F. Marzolo 1, 35131 Padova, Italy
| | - Marco Pirazzini
- Department of Biomedical Sciences, Via U. Bassi 58/B, 35121, Padova, Italy
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Rossetto O, Pirazzini M, Montecucco C. Current gaps in basic science knowledge of botulinum neurotoxin biological actions. Toxicon 2015; 107:59-63. [DOI: 10.1016/j.toxicon.2015.07.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 07/01/2015] [Indexed: 12/27/2022]
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