A Novel Catalytically Inactive Construct of Botulinum Neurotoxin A (BoNT/A) Directly Inhibits Visceral Sensory Signalling
Botulinum neurotoxin A (BoNT/A) is a potent neurotoxin that silences cholinergic neurotransmission through the cleavage of the synaptic protein SNAP-25. Previous studies have shown that, in addition to its paralytic effects, BoNT/A can inhibit sensory nerve activity. The aim of this study was to ide...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2024-01-01
|
| Series: | Toxins |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2072-6651/16/1/30 |
| _version_ | 1797342441544613888 |
|---|---|
| author | Hodan Ibrahim Kevin Retailleau Fraser Hornby Jacquie Maignel Matthew Beard Donna Marie Daly |
| author_facet | Hodan Ibrahim Kevin Retailleau Fraser Hornby Jacquie Maignel Matthew Beard Donna Marie Daly |
| author_sort | Hodan Ibrahim |
| collection | DOAJ |
| description | Botulinum neurotoxin A (BoNT/A) is a potent neurotoxin that silences cholinergic neurotransmission through the cleavage of the synaptic protein SNAP-25. Previous studies have shown that, in addition to its paralytic effects, BoNT/A can inhibit sensory nerve activity. The aim of this study was to identify how BoNT/A inhibits afferent signalling from the bladder. To investigate the role of SNAP-25 cleavage in the previously reported BoNT/A-dependent inhibition of sensory signalling, we developed a recombinant form of BoNT/A with an inactive light chain, rBoNT/A (0), unable to paralyse muscle. We also developed recombinant light chain (LC)-domain-only proteins to better understand the entry mechanisms, as the heavy chain (HC) of the protein is responsible for the internalisation of the light chain. We found that, despite a lack of catalytic activity, rBoNT/A (0) potently inhibited the afferent responses to bladder distension to a greater degree than catalytically active rBoNT/A. This was also clear from the testing of the LC-only proteins, as the inactive rLC/A (0) protein inhibited afferent responses significantly more than the active rLC/A protein. Immunohistochemistry for cleaved SNAP-25 was negative, and purinergic and nitrergic antagonists partially and totally reversed the sensory inhibition, respectively. These data suggest that the BoNT/A inhibition of sensory nerve activity in this assay is not due to the classical well-characterised ‘double-receptor’ mechanism of BoNT/A, is independent of SNAP25 cleavage and involves nitrergic and purinergic signalling mechanisms. |
| first_indexed | 2024-03-08T10:33:21Z |
| format | Article |
| id | doaj.art-539d303bc0134f4480d60c956db88901 |
| institution | Directory Open Access Journal |
| issn | 2072-6651 |
| language | English |
| last_indexed | 2024-03-08T10:33:21Z |
| publishDate | 2024-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Toxins |
| spelling | doaj.art-539d303bc0134f4480d60c956db889012024-01-26T18:42:26ZengMDPI AGToxins2072-66512024-01-011613010.3390/toxins16010030A Novel Catalytically Inactive Construct of Botulinum Neurotoxin A (BoNT/A) Directly Inhibits Visceral Sensory SignallingHodan Ibrahim0Kevin Retailleau1Fraser Hornby2Jacquie Maignel3Matthew Beard4Donna Marie Daly5School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston Campus, Preston PR1 2HE, UKIpsen, 5 av Canada, 91940 Les Ulis, FranceIpsen, Abingdon OX14 4RY, UKIpsen, 5 av Canada, 91940 Les Ulis, FranceIpsen, Abingdon OX14 4RY, UKSchool of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston Campus, Preston PR1 2HE, UKBotulinum neurotoxin A (BoNT/A) is a potent neurotoxin that silences cholinergic neurotransmission through the cleavage of the synaptic protein SNAP-25. Previous studies have shown that, in addition to its paralytic effects, BoNT/A can inhibit sensory nerve activity. The aim of this study was to identify how BoNT/A inhibits afferent signalling from the bladder. To investigate the role of SNAP-25 cleavage in the previously reported BoNT/A-dependent inhibition of sensory signalling, we developed a recombinant form of BoNT/A with an inactive light chain, rBoNT/A (0), unable to paralyse muscle. We also developed recombinant light chain (LC)-domain-only proteins to better understand the entry mechanisms, as the heavy chain (HC) of the protein is responsible for the internalisation of the light chain. We found that, despite a lack of catalytic activity, rBoNT/A (0) potently inhibited the afferent responses to bladder distension to a greater degree than catalytically active rBoNT/A. This was also clear from the testing of the LC-only proteins, as the inactive rLC/A (0) protein inhibited afferent responses significantly more than the active rLC/A protein. Immunohistochemistry for cleaved SNAP-25 was negative, and purinergic and nitrergic antagonists partially and totally reversed the sensory inhibition, respectively. These data suggest that the BoNT/A inhibition of sensory nerve activity in this assay is not due to the classical well-characterised ‘double-receptor’ mechanism of BoNT/A, is independent of SNAP25 cleavage and involves nitrergic and purinergic signalling mechanisms.https://www.mdpi.com/2072-6651/16/1/30botulinum toxinsensorybladdernervemechanosensitivity |
| spellingShingle | Hodan Ibrahim Kevin Retailleau Fraser Hornby Jacquie Maignel Matthew Beard Donna Marie Daly A Novel Catalytically Inactive Construct of Botulinum Neurotoxin A (BoNT/A) Directly Inhibits Visceral Sensory Signalling Toxins botulinum toxin sensory bladder nerve mechanosensitivity |
| title | A Novel Catalytically Inactive Construct of Botulinum Neurotoxin A (BoNT/A) Directly Inhibits Visceral Sensory Signalling |
| title_full | A Novel Catalytically Inactive Construct of Botulinum Neurotoxin A (BoNT/A) Directly Inhibits Visceral Sensory Signalling |
| title_fullStr | A Novel Catalytically Inactive Construct of Botulinum Neurotoxin A (BoNT/A) Directly Inhibits Visceral Sensory Signalling |
| title_full_unstemmed | A Novel Catalytically Inactive Construct of Botulinum Neurotoxin A (BoNT/A) Directly Inhibits Visceral Sensory Signalling |
| title_short | A Novel Catalytically Inactive Construct of Botulinum Neurotoxin A (BoNT/A) Directly Inhibits Visceral Sensory Signalling |
| title_sort | novel catalytically inactive construct of botulinum neurotoxin a bont a directly inhibits visceral sensory signalling |
| topic | botulinum toxin sensory bladder nerve mechanosensitivity |
| url | https://www.mdpi.com/2072-6651/16/1/30 |
| work_keys_str_mv | AT hodanibrahim anovelcatalyticallyinactiveconstructofbotulinumneurotoxinabontadirectlyinhibitsvisceralsensorysignalling AT kevinretailleau anovelcatalyticallyinactiveconstructofbotulinumneurotoxinabontadirectlyinhibitsvisceralsensorysignalling AT fraserhornby anovelcatalyticallyinactiveconstructofbotulinumneurotoxinabontadirectlyinhibitsvisceralsensorysignalling AT jacquiemaignel anovelcatalyticallyinactiveconstructofbotulinumneurotoxinabontadirectlyinhibitsvisceralsensorysignalling AT matthewbeard anovelcatalyticallyinactiveconstructofbotulinumneurotoxinabontadirectlyinhibitsvisceralsensorysignalling AT donnamariedaly anovelcatalyticallyinactiveconstructofbotulinumneurotoxinabontadirectlyinhibitsvisceralsensorysignalling AT hodanibrahim novelcatalyticallyinactiveconstructofbotulinumneurotoxinabontadirectlyinhibitsvisceralsensorysignalling AT kevinretailleau novelcatalyticallyinactiveconstructofbotulinumneurotoxinabontadirectlyinhibitsvisceralsensorysignalling AT fraserhornby novelcatalyticallyinactiveconstructofbotulinumneurotoxinabontadirectlyinhibitsvisceralsensorysignalling AT jacquiemaignel novelcatalyticallyinactiveconstructofbotulinumneurotoxinabontadirectlyinhibitsvisceralsensorysignalling AT matthewbeard novelcatalyticallyinactiveconstructofbotulinumneurotoxinabontadirectlyinhibitsvisceralsensorysignalling AT donnamariedaly novelcatalyticallyinactiveconstructofbotulinumneurotoxinabontadirectlyinhibitsvisceralsensorysignalling |