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Lamotte JDD, Roqueviere S, Gautier H, Raban E, Bouré C, Fonfria E, Krupp J, Nicoleau C. hiPSC-Derived Neurons Provide a Robust and Physiologically Relevant In Vitro Platform to Test Botulinum Neurotoxins. Front Pharmacol 2021; 11:617867. [PMID: 33519485 PMCID: PMC7840483 DOI: 10.3389/fphar.2020.617867] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 11/26/2020] [Indexed: 12/16/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) are zinc metalloproteases that block neurotransmitter release at the neuromuscular junction (NMJ). Their high affinity for motor neurons combined with a high potency have made them extremely effective drugs for the treatment of a variety of neurological diseases as well as for aesthetic applications. Current in vitro assays used for testing and developing BoNT therapeutics include primary rodent cells and immortalized cell lines. Both models have limitations concerning accuracy and physiological relevance. In order to improve the translational value of preclinical data there is a clear need to use more accurate models such as human induced Pluripotent Stem Cells (hiPSC)-derived neuronal models. In this study we have assessed the potential of four different human iPSC-derived neuronal models including Motor Neurons for BoNT testing. We have characterized these models in detail and found that all models express all proteins needed for BoNT intoxication and showed that all four hiPSC-derived neuronal models are sensitive to both serotype A and E BoNT with Motor Neurons being the most sensitive. We showed that hiPSC-derived Motor Neurons expressed authentic markers after only 7 days of culture, are functional and able to form active synapses. When cultivated with myotubes, we demonstrated that they can innervate myotubes and induce contraction, generating an in vitro model of NMJ showing dose-responsive sensitivity BoNT intoxication. Together, these data demonstrate the promise of hiPSC-derived neurons, especially Motor Neurons, for pharmaceutical BoNT testing and development.
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2
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Yeo J, Loss O, Ziomkiewicz I, Krupp J, Tay F, Foster K, Beard M, Bard F. BoNT intoxication: Functional genomics reveals an unexpected trafficking route. Toxicon 2021. [DOI: 10.1016/j.toxicon.2020.11.502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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3
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Bonello F, Hassoun SM, Mouton-Liger F, Shin YS, Muscat A, Tesson C, Lesage S, Beart PM, Brice A, Krupp J, Corvol JC, Corti O. LRRK2 impairs PINK1/Parkin-dependent mitophagy via its kinase activity: pathologic insights into Parkinson's disease. Hum Mol Genet 2020; 28:1645-1660. [PMID: 30629163 DOI: 10.1093/hmg/ddz004] [Citation(s) in RCA: 104] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 12/05/2018] [Accepted: 01/01/2019] [Indexed: 11/12/2022] Open
Abstract
Mutations of LRRK2, encoding leucine-rich repeat kinase 2 (LRRK2), are the leading cause of autosomal dominant Parkinson's disease (PD). The most frequent of these mutations, G2019S substitution, increases kinase activity, but it remains unclear how it causes PD. Recent studies suggest that LRRK2 modulates mitochondrial homeostasis. Mitochondrial dysfunction plays a key role in the pathogenesis of autosomal recessive PD forms linked to PARK2 and PINK1, encoding the cytosolic E3 ubiquitin-protein ligase Parkin and the mitochondrial kinase PINK1, which jointly regulate mitophagy. We explored the role of LRRK2 and its kinase activity in PINK1/Parkin-dependent mitophagy. LRRK2 increased mitochondrial aggregation and attenuated mitochondrial clearance in cells coexpressing Parkin and exposed to the protonophore carbonylcyanide m-chlorophenylhydrazone. Förster resonance energy transfer imaging microscopy showed that LRRK2 impaired the interactions between Parkin and Drp1 and their mitochondrial targets early in mitophagy. The inhibition of LRRK2 kinase activity by a 'kinase-dead' LRRK2 mutation or with a pharmacological inhibitor (LRRK2-IN-1) restored these interactions. The monitoring of mitophagy in human primary fibroblasts with the novel dual-fluorescence mtRosella reporter and a new hypothermic shock paradigm revealed similar defects in PD patients with the G2019S LRRK2 substitution or PARK2 mutations relative to healthy subjects. This defect was restored by LRRK2-IN-1 treatment in LRRK2 patients only. Our results suggest that PD forms due to LRRK2 and PARK2 mutations involve pathogenic mechanisms converging on PINK1/Parkin-dependent mitophagy.
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Affiliation(s)
- Fiona Bonello
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, France.,Inserm, Paris, France.,CNRS, UMR, Paris, France.,Sorbonne Universités, Paris, France
| | - Sidi-Mohamed Hassoun
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, France.,Inserm, Paris, France.,CNRS, UMR, Paris, France.,Sorbonne Universités, Paris, France
| | - François Mouton-Liger
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, France.,Inserm, Paris, France.,CNRS, UMR, Paris, France.,Sorbonne Universités, Paris, France
| | - Yea Seul Shin
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Adeline Muscat
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, France.,Inserm, Paris, France.,CNRS, UMR, Paris, France.,Sorbonne Universités, Paris, France
| | - Christelle Tesson
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, France.,Inserm, Paris, France.,CNRS, UMR, Paris, France.,Sorbonne Universités, Paris, France
| | - Suzanne Lesage
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, France.,Inserm, Paris, France.,CNRS, UMR, Paris, France.,Sorbonne Universités, Paris, France
| | - Philip M Beart
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Alexis Brice
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, France.,Inserm, Paris, France.,CNRS, UMR, Paris, France.,Sorbonne Universités, Paris, France.,AP-HP, Hôpital de la Pitié-Salpêtrière, Department of Genetics, Paris, France
| | | | - Jean-Christophe Corvol
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, France.,Inserm, Paris, France.,CNRS, UMR, Paris, France.,Sorbonne Universités, Paris, France.,AP-HP, Hôpital de la Pitié-Salpêtrière, Clinical Investigation Center for Neurology (CIC), Department of Neurology, Hôpital Pitié-Salpêtrière, Paris, France
| | - Olga Corti
- Institut du Cerveau et de la Moelle épinière, ICM, Paris, France.,Inserm, Paris, France.,CNRS, UMR, Paris, France.,Sorbonne Universités, Paris, France
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4
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Elliott M, Favre-Guilmard C, Liu SM, Maignel J, Masuyer G, Beard M, Boone C, Carré D, Kalinichev M, Lezmi S, Mir I, Nicoleau C, Palan S, Perier C, Raban E, Zhang S, Dong M, Stenmark P, Krupp J. Engineered botulinum neurotoxin B with improved binding to human receptors has enhanced efficacy in preclinical models. Sci Adv 2019; 5:eaau7196. [PMID: 30746458 PMCID: PMC6357751 DOI: 10.1126/sciadv.aau7196] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 12/06/2018] [Indexed: 05/10/2023]
Abstract
Although botulinum neurotoxin serotype A (BoNT/A) products are common treatments for various disorders, there is only one commercial BoNT/B product, whose low potency, likely stemming from low affinity toward its human receptor synaptotagmin 2 (hSyt2), has limited its therapeutic usefulness. We express and characterize two full-length recombinant BoNT/B1 proteins containing designed mutations E1191M/S1199Y (rBoNT/B1MY) and E1191Q/S1199W (rBoNT/B1QW) that enhance binding to hSyt2. In preclinical models including human-induced pluripotent stem cell neurons and a humanized transgenic mouse, this increased hSyt2 affinity results in high potency, comparable to that of BoNT/A. Last, we solve the cocrystal structure of rBoNT/B1MY in complex with peptides of hSyt2 and its homolog hSyt1. We demonstrate that neuronal surface receptor binding limits the clinical efficacy of unmodified BoNT/B and that modified BoNT/B proteins have promising clinical potential.
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MESH Headings
- Animals
- Botulinum Toxins, Type A/chemistry
- Botulinum Toxins, Type A/genetics
- Botulinum Toxins, Type A/metabolism
- Botulinum Toxins, Type A/pharmacology
- Crystallography, X-Ray
- Female
- Glycine/metabolism
- Humans
- Induced Pluripotent Stem Cells/drug effects
- Male
- Mice, Inbred C57BL
- Mice, Transgenic
- Muscle, Skeletal/drug effects
- Muscle, Smooth/drug effects
- Mutation
- Neurons/drug effects
- Neurons/metabolism
- Protein Engineering
- Rabbits
- Rats, Sprague-Dawley
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Recombinant Proteins/pharmacology
- Static Electricity
- Synaptotagmin II/chemistry
- Synaptotagmin II/genetics
- Synaptotagmin II/metabolism
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Affiliation(s)
- Mark Elliott
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK
| | | | - Sai Man Liu
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK
| | - Jacquie Maignel
- Ipsen Innovation, 5 Avenue du Canada, 91940 Les Ulis, France
| | - Geoffrey Masuyer
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm SE-106 91, Sweden
| | - Matthew Beard
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK
| | - Christopher Boone
- Department of Urology, Boston Children’s Hospital, Department of Microbiology and Immunobiology and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Denis Carré
- Ipsen Innovation, 5 Avenue du Canada, 91940 Les Ulis, France
| | | | - Stephane Lezmi
- Ipsen Innovation, 5 Avenue du Canada, 91940 Les Ulis, France
| | - Imran Mir
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK
| | | | - Shilpa Palan
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK
| | - Cindy Perier
- Ipsen Innovation, 5 Avenue du Canada, 91940 Les Ulis, France
| | - Elsa Raban
- Ipsen Innovation, 5 Avenue du Canada, 91940 Les Ulis, France
| | - 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
| | - 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, Stockholm SE-106 91, Sweden
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Johannes Krupp
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK
- Ipsen Innovation, 5 Avenue du Canada, 91940 Les Ulis, France
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5
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Donald S, Elliott M, Gray B, Hornby F, Lewandowska A, Marlin S, Favre-Guilmard C, Périer C, Cornet S, Kalinichev M, Krupp J, Fonfria E. A comparison of biological activity of commercially available purified native botulinum neurotoxin serotypes A1 to F1 in vitro, ex vivo, and in vivo. Pharmacol Res Perspect 2018; 6:e00446. [PMID: 30519475 PMCID: PMC6261930 DOI: 10.1002/prp2.446] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 10/24/2018] [Accepted: 10/25/2018] [Indexed: 01/12/2023] Open
Abstract
Botulinum neurotoxin (BoNT) is a major therapeutic agent. Of seven native BoNT serotypes (A to G), only A and B are currently used in the clinic. Here we compared the potency of commercially available purified native serotypes A1 to F1 across in vitro, ex vivo, and in vivo assays. BoNT potency in vitro was assessed in rat primary cells (target protein cleavage and neurotransmitter release assays) in supraspinal, spinal, and sensory systems. BoNT potency ex vivo was measured in the mouse phrenic nerve hemidiaphragm (PNHD) assay, measuring muscle contractility. In vivo, BoNT-induced muscle relaxation in mice and rats was assessed in the Digit Abduction Score (DAS) test, while effects on body weight (BW) gain were used to assess tolerability. In all assays, all BoNT serotypes were potent toxins, except serotype D1 in vivo which failed to produce significant muscle flaccidity in mice and rats. In rats, all serotypes were well-tolerated, whereas in mice, reductions in BW were detected at high doses. Serotype A1 was the most potent serotype across in vitro, ex vivo, and in vivo assays. The rank order of potency of the serotypes revealed differences among assays. For example, species-specificity was seen for serotype B1, and to a lesser extent for serotype C1. Serotypes F1 and C1, not currently in the clinic, showed preference for sensory over motor models and therefore could be considered for development in conditions involving the somatosensory system.
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6
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Nicoleau C, De Lamotte JD, Raban E, Boude E, Noirmain F, Krupp J. Assessment of multiple hiPSC-derived models for botulinum neurotoxin testing. Toxicon 2018. [DOI: 10.1016/j.toxicon.2018.11.206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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7
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Elliott M, Favre-Guilmard C, Liu SM, Maignel J, Masuyer G, Beard M, Boone C, Carré D, Kalinichev M, Lezmi S, Mir I, Nicoleau C, Palan S, Perier C, Raban E, Zhang S, Dong M, Stenmark P, Krupp J. Botulinum neurotoxin B engineered for increased receptor affinity has improved clinical potential. Toxicon 2018. [DOI: 10.1016/j.toxicon.2018.11.070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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8
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Nicoleau C, Buttigieg D, Henriques S, Krupp J, Maignel J, Raban E, Marlin S, Steinschneider R, Foster K. Development of an in vitro human neuromuscular junction. Toxicon 2018. [DOI: 10.1016/j.toxicon.2018.11.204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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9
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Beard M, Burgin D, Hornby F, Donald S, Krupp J, Dong M, Stenmark P, Foster K. Recombinant expression and characterization of a botulinum neurotoxin serotype X chimera. Toxicon 2018. [DOI: 10.1016/j.toxicon.2018.11.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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10
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Loss O, Elliott M, Krupp J. Engineering fluorescent-labeled botulinum neurotoxins and derivatives to image their trafficking in neuronal and non-neuronal cells. Toxicon 2018. [DOI: 10.1016/j.toxicon.2018.11.167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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11
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Maignel J, Gorny D, Joly AL, Kouidri Y, Martin V, Lezmi S, Assaly R, Behr-Roussel D, Lebret T, Radulescu C, Beard M, Krupp J. Exploring the effect of various BoNT serotypes in a model of autonomic nervous system hyperactivity from rodents and humans: Paving the way to better targeting therapeutics in autonomic disorders? Toxicon 2018. [DOI: 10.1016/j.toxicon.2018.11.173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Nicoleau C, Donald S, Pons L, De Lamotte JD, Raban E, Fonfria E, Krupp J. Translational value of hiPSC-derived models for botulinum neurotoxin research. Toxicon 2018. [DOI: 10.1016/j.toxicon.2018.11.205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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13
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Fonfria E, Elliott M, Beard M, Chaddock JA, Krupp J. Engineering Botulinum Toxins to Improve and Expand Targeting and SNARE Cleavage Activity. Toxins (Basel) 2018; 10:toxins10070278. [PMID: 29973505 PMCID: PMC6071219 DOI: 10.3390/toxins10070278] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 06/29/2018] [Accepted: 07/01/2018] [Indexed: 12/14/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) are highly successful protein therapeutics. Over 40 naturally occurring BoNTs have been described thus far and, of those, only 2 are commercially available for clinical use. Different members of the BoNT family present different biological properties but share a similar multi-domain structure at the molecular level. In nature, BoNTs are encoded by DNA in producing clostridial bacteria and, as such, are amenable to recombinant production through insertion of the coding DNA into other bacterial species. This, in turn, creates possibilities for protein engineering. Here, we review the production of BoNTs by the natural host and also recombinant production approaches utilised in the field. Applications of recombinant BoNT-production include the generation of BoNT-derived domain fragments, the creation of novel BoNTs with improved performance and enhanced therapeutic potential, as well as the advancement of BoNT vaccines. In this article, we discuss site directed mutagenesis, used to affect the biological properties of BoNTs, including approaches to alter their binding to neurons and to alter the specificity and kinetics of substrate cleavage. We also discuss the target secretion inhibitor (TSI) platform, in which the neuronal binding domain of BoNTs is substituted with an alternative cellular ligand to re-target the toxins to non-neuronal systems. Understanding and harnessing the potential of the biological diversity of natural BoNTs, together with the ability to engineer novel mutations and further changes to the protein structure, will provide the basis for increasing the scope of future BoNT-based therapeutics.
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Affiliation(s)
- Elena Fonfria
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
| | - Mark Elliott
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
| | - Matthew Beard
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
| | - John A Chaddock
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
| | - Johannes Krupp
- Ipsen Innovation, 5 Avenue du Canada, 91940 Les Ulis, France.
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14
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Fonfria E, Maignel J, Lezmi S, Martin V, Splevins A, Shubber S, Kalinichev M, Foster K, Picaut P, Krupp J. The Expanding Therapeutic Utility of Botulinum Neurotoxins. Toxins (Basel) 2018; 10:E208. [PMID: 29783676 PMCID: PMC5983264 DOI: 10.3390/toxins10050208] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 05/15/2018] [Accepted: 05/16/2018] [Indexed: 12/11/2022] Open
Abstract
Botulinum neurotoxin (BoNT) is a major therapeutic agent that is licensed in neurological indications, such as dystonia and spasticity. The BoNT family, which is produced in nature by clostridial bacteria, comprises several pharmacologically distinct proteins with distinct properties. In this review, we present an overview of the current therapeutic landscape and explore the diversity of BoNT proteins as future therapeutics. In recent years, novel indications have emerged in the fields of pain, migraine, overactive bladder, osteoarthritis, and wound healing. The study of biological effects distal to the injection site could provide future opportunities for disease-tailored BoNT therapies. However, there are some challenges in the pharmaceutical development of BoNTs, such as liquid and slow-release BoNT formulations; and, transdermal, transurothelial, and transepithelial delivery. Innovative approaches in the areas of formulation and delivery, together with highly sensitive analytical tools, will be key for the success of next generation BoNT clinical products.
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Affiliation(s)
- Elena Fonfria
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY, UK.
| | - Jacquie Maignel
- Ipsen Innovation, 5 Avenue du Canada, 91940 Les Ulis, France.
| | - Stephane Lezmi
- Ipsen Innovation, 5 Avenue du Canada, 91940 Les Ulis, France.
| | - Vincent Martin
- Ipsen Innovation, 5 Avenue du Canada, 91940 Les Ulis, France.
| | - Andrew Splevins
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY, UK.
| | - Saif Shubber
- Ipsen Biopharm Ltd., Wrexham Industrial Estate, 9 Ash Road, Wrexham LL13 9UF, UK.
| | | | - Keith Foster
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY, UK.
| | - Philippe Picaut
- Ipsen Bioscience, 650 Kendall Street, Cambridge, MA 02142, USA.
| | - Johannes Krupp
- Ipsen Innovation, 5 Avenue du Canada, 91940 Les Ulis, France.
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15
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Elliott M, Maignel J, Liu SM, Favre-Guilmard C, Mir I, Farrow P, Hornby F, Marlin S, Palan S, Beard M, Krupp J. Augmentation of VAMP-catalytic activity of botulinum neurotoxin serotype B does not result in increased potency in physiological systems. PLoS One 2017; 12:e0185628. [PMID: 28982136 PMCID: PMC5628846 DOI: 10.1371/journal.pone.0185628] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 09/15/2017] [Indexed: 11/19/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) are used extensively as therapeutic agents. Serotypes A and B are available as marketed products. Higher doses of BoNT/B are required to reach an efficacy similar to that of products containing BoNT/A. Advances in our understanding of BoNT/B mechanism of action have afforded the opportunity to make rational modifications to the toxin aimed at increasing its activity. Recently, a mutation in the light chain of BoNT/B (S201P) was described that increases the catalytic activity of the isolated BoNT/B light chain in biochemical assays. In this study, we have produced two full-length recombinant BoNT/B toxins in E.coli-one wild type (rBoNT/B1) and one incorporating the S201P mutation (rBoNT/B1(S201P)). We have compared the activity of these two molecules along with a native BoNT/B1 in biochemical cell-free assays and in several biological systems. In the cell-free assay, which measured light-chain activity alone, rBoNT/B1(S201P) cleaved VAMP-2 and VAMP-1 substrate with an activity 3-4-fold higher than rBoNT/B1. However, despite the enhanced catalytic activity of rBoNT/B1(S201P), there was no significant difference in potency between the two molecules in any of the in vitro cell-based assays, using either rodent spinal cord neurons or cortical neurons. Similarly in ex vivo tissue preparations rBoNT/B1(S201P) was not significantly more potent than rBoNT/B1 at inhibiting either diaphragm or detrusor (bladder) muscle activity in C57BL/6N and CD1 mice. Finally, no differences between rBoNT/B1 and rBoNT/B1(S201P) were observed in an in vivo digit abduction score (DAS) assay in C57BL/6N mice, either in efficacy or safety parameters. The lack of translation from the enhanced BoNT/B1(S201P) catalytic activity to potency in complex biological systems suggests that the catalytic step is not the rate-limiting factor for BoNT/B to reach maximum efficacy. In order to augment the efficacy of BoNT/B in humans, strategies other than enhancing light chain activity may need to be considered.
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Affiliation(s)
- Mark Elliott
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon, United Kingdom
- * E-mail:
| | | | - Sai Man Liu
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon, United Kingdom
| | | | - Imran Mir
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon, United Kingdom
| | - Paul Farrow
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon, United Kingdom
| | - Fraser Hornby
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon, United Kingdom
| | - Sandra Marlin
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon, United Kingdom
| | - Shilpa Palan
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon, United Kingdom
| | - Matthew Beard
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon, United Kingdom
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16
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Wirth S, Krupp J, Bolzer M, Reiser M, Fischer M. Thoraxradiografie: Güte von Befundung, Beurteilung und Selbsteinschätzung in Abhängigkeit von Fallschwierigkeit, realem Vorgehen während der Bildbefundung (eye-tracking) und des Weiterbildungsstands. ROFO-FORTSCHR RONTG 2017. [DOI: 10.1055/s-0037-1600455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- S Wirth
- Ludwigs-Maximilians-Universität München, Institut für Klinische Radiologie, München
| | - J Krupp
- Ludwigs-Maximilians-Universität München, Institut für Klinische Radiologie, München
| | - M Bolzer
- Ludwigs-Maximilians-Universität München, Institut für medizinische Didaktiv und Ausbildungsforschung, München
| | - M Reiser
- Ludwigs-Maximilians-Universität München, Institut für Klinische Radiologie, München
| | - M Fischer
- Ludwigs-Maximilians-Universität München, Institut für medizinische Didaktiv und Ausbildungsforschung, München
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Maignel-Ludop J, Huchet M, Krupp J. Botulinum Neurotoxins Serotypes A and B induce paralysis of mouse striated and smooth muscles with different potencies. Pharmacol Res Perspect 2017; 5:e00289. [PMID: 28596838 PMCID: PMC5461647 DOI: 10.1002/prp2.289] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 11/10/2016] [Accepted: 11/16/2016] [Indexed: 01/23/2023] Open
Abstract
To address the scarcity of direct comparison of botulinum neurotoxin serotypes activity on smooth versus striatal muscle, we have studied the action of BoNT/A1 and BoNT/B1 on ex vivo preparations of both muscle types. We have set up and characterized a model of neurogenic contractions in the isolated mouse bladder, and used this model to explore the effects of the two serotypes on contractions evoked by electrical field stimulation. Both toxins were also tested in the mouse phrenic nerve hemidiaphragm assay, to compare their potency in smooth versus striated muscle. The characterization of the model of neurogenic contractions in the isolated mouse bladder indicates that about half of the activity is driven by purinergic signaling, and about half by cholinergic signaling. Furthermore, we find that BoNT/B1 is more potent than BoNT/A1 in inhibiting activity in the mouse detrusor smooth muscle preparation, but that both toxins have comparable potency on the striated muscle activity of the phrenic nerve hemidiaphragm model. We also show that these findings are mouse strain independent. In conclusion, the established mouse bladder detrusor smooth muscle model is able to discriminate between different botulinum neurotoxin serotypes and could be a useful preclinical tool to explore the pathophysiology of bladder overactivity, as well as the effects of new therapeutic candidates. It is interesting to note that the high proportion of purinergic transmission driving detrusor contractions in this model is similar to that seen in neurodetrusor overactivity disease, making this model relevant with regard to pathophysiological interest.
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Affiliation(s)
| | - Marion Huchet
- Neurology ResearchIpsen Innovation 5 Avenue du Canada 91940 Les Ulis France
| | - Johannes Krupp
- Neurology ResearchIpsen Innovation 5 Avenue du Canada 91940 Les Ulis France
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Maignel-Ludop J, Pignol B, Gorny D, Assaly R, Behr-Roussel D, Krupp J. Human and mouse isolated bladder preparations are not equally affected by botulinum neurotoxin serotypes A and B. Toxicon 2016. [DOI: 10.1016/j.toxicon.2016.11.166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Elliott M, Farrow P, Favre-Guilmard C, Hornby F, Liu SM, Maignel-Ludop J, Marlin S, Mir I, Palan S, Kalinichev M, Beard M, Krupp J. Augmentation of the catalytic activity of Botulinum neurotoxin type B does not result in increased potency in physiologic systems. Toxicon 2016. [DOI: 10.1016/j.toxicon.2016.11.075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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21
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Kist AM, Sagafos D, Rush AM, Neacsu C, Eberhardt E, Schmidt R, Lunden LK, Ørstavik K, Kaluza L, Meents J, Zhang Z, Carr TH, Salter H, Malinowsky D, Wollberg P, Krupp J, Kleggetveit IP, Schmelz M, Jørum E, Lampert A, Namer B. SCN10A Mutation in a Patient with Erythromelalgia Enhances C-Fiber Activity Dependent Slowing. PLoS One 2016; 11:e0161789. [PMID: 27598514 PMCID: PMC5012686 DOI: 10.1371/journal.pone.0161789] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 08/11/2016] [Indexed: 11/18/2022] Open
Abstract
Gain-of-function mutations in the tetrodotoxin (TTX) sensitive voltage-gated sodium channel (Nav) Nav1.7 have been identified as a key mechanism underlying chronic pain in inherited erythromelalgia. Mutations in TTX resistant channels, such as Nav1.8 or Nav1.9, were recently connected with inherited chronic pain syndromes. Here, we investigated the effects of the p.M650K mutation in Nav1.8 in a 53 year old patient with erythromelalgia by microneurography and patch-clamp techniques. Recordings of the patient’s peripheral nerve fibers showed increased activity dependent slowing (ADS) in CMi and less spontaneous firing compared to a control group of erythromelalgia patients without Nav mutations. To evaluate the impact of the p.M650K mutation on neuronal firing and channel gating, we performed current and voltage-clamp recordings on transfected sensory neurons (DRGs) and neuroblastoma cells. The p.M650K mutation shifted steady-state fast inactivation of Nav1.8 to more hyperpolarized potentials and did not significantly alter any other tested gating behaviors. The AP half-width was significantly broader and the stimulated action potential firing rate was reduced for M650K transfected DRGs compared to WT. We discuss the potential link between enhanced steady state fast inactivation, broader action potential width and the potential physiological consequences.
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Affiliation(s)
- Andreas M. Kist
- Institute of Physiology and Pathophysiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Dagrun Sagafos
- Section of Clinical Neurophysiology, Department of Neurology, Oslo University Hospital -Rikshospitalet, Oslo, Norway
| | | | - Cristian Neacsu
- Institute of Physiology and Pathophysiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Esther Eberhardt
- Institute of Physiology and Pathophysiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
- Department of Anesthesiology, Friedrich-Alexander-Universität Erlangen-Nuremberg, Erlangen, Germany
| | - Roland Schmidt
- Department of Neuroscience, Clinical Neurophysiology, Uppsala University, Uppsala, Sweden
| | - Lars Kristian Lunden
- Section of Clinical Neurophysiology, Department of Neurology, Oslo University Hospital -Rikshospitalet, Oslo, Norway
| | - Kristin Ørstavik
- Section of Clinical Neurophysiology, Department of Neurology, Oslo University Hospital -Rikshospitalet, Oslo, Norway
| | - Luisa Kaluza
- Institute of Physiology, RWTH Aachen University Hospital, Aachen, Germany
| | - Jannis Meents
- Institute of Physiology, RWTH Aachen University Hospital, Aachen, Germany
| | | | | | | | | | | | | | - Inge Petter Kleggetveit
- Section of Clinical Neurophysiology, Department of Neurology, Oslo University Hospital -Rikshospitalet, Oslo, Norway
| | - Martin Schmelz
- Department of Anesthesiology Mannheim, Heidelberg University, Mannheim, Germany
| | - Ellen Jørum
- Section of Clinical Neurophysiology, Department of Neurology, Oslo University Hospital -Rikshospitalet, Oslo, Norway
- * E-mail: (EJ); (AL); (BN)
| | - Angelika Lampert
- Institute of Physiology and Pathophysiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
- Institute of Physiology, RWTH Aachen University Hospital, Aachen, Germany
- * E-mail: (EJ); (AL); (BN)
| | - Barbara Namer
- Institute of Physiology and Pathophysiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
- Department of Anesthesiology Mannheim, Heidelberg University, Mannheim, Germany
- * E-mail: (EJ); (AL); (BN)
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Hornby F, Hedley D, Fonfria E, Krupp J. 105. Effect of botulinum neurotoxin type A subtypes on guinea pig isolated ileum smooth muscle. Toxicon 2015. [DOI: 10.1016/j.toxicon.2014.11.108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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23
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Delaflotte S, Carré D, Krupp J, Huchet M. 60. Development of an enriched and highly BoNT/A1-sensitive motor neuron culture. Toxicon 2015. [DOI: 10.1016/j.toxicon.2014.11.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Jonsson Fagerlund M, Sjödin J, Dabrowski MA, Krupp J. Reduced efficacy of the intravenous anesthetic agent AZD3043 at GABAA receptors with β2 (N289M) and β3 (N290M) point-mutations. Eur J Pharmacol 2012; 694:13-9. [DOI: 10.1016/j.ejphar.2012.07.040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 07/16/2012] [Accepted: 07/28/2012] [Indexed: 11/30/2022]
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Levitsky J, Baker T, Ahya SN, Levin ML, Friedewald J, Gallon L, Ho B, Skaro A, Krupp J, Wang E, Spies SM, Salomon DR, Abecassis MM. Outcomes and native renal recovery following simultaneous liver-kidney transplantation. Am J Transplant 2012; 12:2949-57. [PMID: 22759344 DOI: 10.1111/j.1600-6143.2012.04182.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
With the increase in patients having impaired renal function at liver transplant due to MELD, accurate predictors of posttransplant native renal recovery are needed to select candidates for simultaneous liver-kidney transplantation (SLK). Current UNOS guidelines rely on specific clinical criteria for SLK allocation. To examine these guidelines and other variables predicting nonrecovery, we analyzed 155 SLK recipients, focusing on a subset (n = 78) that had post-SLK native GFR (nGFR) determined by radionuclide renal scans. The 77 patients not having renal scans received a higher number of extended criteria donor organs and had worse posttransplant survival. Of the 78 renal scan patients, 31 met and 47 did not meet pre-SLK UNOS criteria. The UNOS criteria were more predictive than our institutional criteria for all nGFR recovery thresholds (20-40 mL/min), although at the most conservative cut-off (nGFR ≤ 20) it had low sensitivity (55.3%), specificity (75%), PPV (67.6%) and NPV (63.8%) for predicting post-SLK nonrecovery. On multivariate analysis, the only predictor of native renal nonrecovery (nGFR ≤ 20) was abnormal pre-SLK renal imaging (OR 3.85, CI 1.22-12.5). Our data support the need to refine SLK selection utilizing more definitive biomarkers and predictors of native renal recovery than current clinical criteria.
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Affiliation(s)
- J Levitsky
- Comprehensive Transplant Center, Northwestern University, Chicago, IL, USA.
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Jonsson Fagerlund M, Sjödin J, Krupp J, Dabrowski M. Reduced effect of propofol at human α1β2(N289M)γ2 and α2β3(N290M)γ2 mutant GABA A receptors †. Br J Anaesth 2010; 104:472-81. [DOI: 10.1093/bja/aeq023] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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27
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Trivedi S, Dekermendjian K, Julien R, Huang J, Lund PE, Krupp J, Kronqvist R, Larsson O, Bostwick R. Cellular HTS assays for pharmacological characterization of Na(V)1.7 modulators. Assay Drug Dev Technol 2008; 6:167-79. [PMID: 18078380 DOI: 10.1089/adt.2007.090] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Ion channels are challenging targets in the early phases of the drug discovery process, especially because of the lack of technologies available to screen large numbers of compounds in functionally relevant assays. The electrophysiological patch-clamp technique, which is the gold standard for studying ion channels, has low throughput and is not amenable to screening large numbers of compounds. However, for random high-throughput screening (HTS) of compounds against ion channel targets, a number of functional cellular assays have become available during the last few years. Here we use the sodium channel NaV1.7 stably expressed in human embryonic kidney 293 cells and compare three HTS assays-a Li flux atomic absorption spectroscopy (AAS) assay, a fluorescent imaging plate reader (FLIP, Molecular Devices, Sunnyvale, CA) membrane potential assay, and a fluorescence resonance energy transfer (FRET)-based membrane potential assay-to an automated electrophysiological assay (the Ionworks HT [Molecular Devices] platform) and characterize 11 known NaV inhibitors. Our results show that all three HTS assays are suitable for identification of NaV1.7 inhibitors, but as an HTS assay the Li-AAS assay is more robust with higher Z' values than the FLIPR and FRET-based membrane potential assays. Furthermore, there was a better correlation between the Ionworks assay and the Li-AAS assay regarding the potency of the NaV inhibitors investigated. This paper describes the first comparison between all the HTS assays available today to study voltage-gated NaVs, and the results suggest that the Li-AAS assay is more suited as a first HTS assay when starting an NaV drug discovery campaign.
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Affiliation(s)
- Shephali Trivedi
- HTS Center and Global Support Department, AstraZeneca Pharmaceuticals, Wilmington, DE 19850, USA.
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Chatelier A, Dahllund L, Eriksson A, Krupp J, Chahine M. Biophysical properties of human Na v1.7 splice variants and their regulation by protein kinase A. J Neurophysiol 2008; 99:2241-50. [PMID: 18337362 DOI: 10.1152/jn.01350.2007] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The sodium channel Na(v)1.7 is preferentially expressed in nociceptive neurons and is believed to play a crucial role in pain sensation. Four alternative splice variants are expressed in human dorsal root ganglion neurons, two of which differ in exon 5 by two amino acids in the S3 segment of domain I (exons 5A and 5N). Two others differ in exon 11 by the presence (11L) or absence (11S) of an 11 amino acid sequence in the loop between domains I and II, an important region for PKA regulation. In the present study, we used the whole cell configuration of the patch-clamp technique to investigate the biophysical properties and 8-bromo-cyclic adenosine monophosphate (8Br-cAMP) modulation of these splice variants expressed in tsA201 cells in the presence of the beta(1)-subunit. The alternative splicing of Na(v)1.7 had no effect on most of the biophysical properties of this channel, including activation, inactivation, and recovery from inactivation. However, development of inactivation experiments revealed that the isoform containing exon 5A had slower kinetics of inactivation for negative potentials than that of the variant containing exon 5N. This difference was associated with higher ramp current amplitudes for isoforms containing exon 5A. Moreover, 8Br-cAMP-mediated phosphorylation induced a negative shift of the activation curve of variants containing exon 11S, whereas inactivation properties were unchanged. Isoforms with exon 11L were not modulated by 8Br-cAMP-induced phosphorylation. We conclude that alternative splicing of human Na(v)1.7 can specifically modulate the biophysical properties and cAMP-mediated regulation of this channel. Changing the proportions of these variants may thus influence neuronal excitability and pain sensation.
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Affiliation(s)
- Aurélien Chatelier
- Centre de Recherche, Université Laval Robert-Giffard, 2601 chemin de la Canardière, Quebec City, QC, Canada
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Morinville A, Fundin B, Meury L, Juréus A, Sandberg K, Krupp J, Ahmad S, O'Donnell D. Distribution of the voltage-gated sodium channel Na(v)1.7 in the rat: expression in the autonomic and endocrine systems. J Comp Neurol 2008; 504:680-9. [PMID: 17722032 DOI: 10.1002/cne.21484] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
It is generally accepted that the voltage-gated, tetrodotoxin-sensitive sodium channel, Na(V)1.7, is selectively expressed in peripheral ganglia. However, global deletion in mice of Na(V)1.7 leads to death shortly after birth (Nassar et al. [2004] Proc. Natl. Acad. Sci. U. S. A. 101:12706-12711), suggesting that this ion channel might be more widely expressed. To understand better the potential physiological function of this ion channel, we examined Na(V)1.7 expression in the rat by in situ hybridization and immunohistochemistry. As expected, highest mRNA expression levels are found in peripheral ganglia, and the protein is expressed within these ganglion cells and on the projections of these neurons in the central nervous system. Importantly, we found that Na(V)1.7 is present in discrete rat brain regions, and the unique distribution pattern implies a central involvement in endocrine and autonomic systems as well as analgesia. In addition, Na(V)1.7 expression was detected in the pituitary and adrenal glands. These results indicate that Na(V)1.7 is not only involved in the processing of sensory information but also participates in the regulation of autonomic and endocrine systems; more specifically, it could be implicated in such vital functions as fluid homeostasis and cardiovascular control.
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Affiliation(s)
- Anne Morinville
- Department of Molecular Sciences, AstraZeneca R&D Montreal, Ville-St-Laurent, Quebec, H4S 1Z9, Canada
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Abstract
The time pattern of glycinergic inhibitory postsynaptic currents (IPSCs) in sympathetic preganglionic neurons was studied in thin transverse spinal cord slices of neonatal (1-10 days postnatal) rats by means of the patchclamp technique. Three time patterns could be distinguished: (i) large events [mostly > 400 pA (30-36 degrees C)] occurring at regular intervals, (ii) small events occurring at irregular intervals, and (iii) small events occurring in transient (1.5-10 s), high-frequency (> 15 Hz) bursts of synaptic activity. The large regular events had uniform kinetics which was consistent with the idea of a proximal site of origin for all of these events. They were reversibly inhibited in amplitude and frequency by extracellular application of a high concentration of acetylcholine (200 microM) or the specific nicotinic acetylcholine receptor agonist dimethylphenylpiperazinium iodide (DMPP; 1 mM), but unaffected by glutamate (100 microM). IPSCs occurring in bursts had slower and less uniform kinetics, suggesting a more diverse site of origin. The frequency of events decreased during a burst. Similar bursts could be induced by extracellular application of glutamate receptor agonists. These results indicate that sympathetic pregnanglionic neurons in a thin, transverse spinal cord slice receive at least two different glycinergic inputs.
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Affiliation(s)
- J Krupp
- Institut de Physiologie Générale, Centre National de la Recherche Scientifique, Université Louis Pasteur, Strasbourg, France
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Abstract
1. We obtained whole cell patch-clamp recordings from visually identified sympathetic preganglionic neurons (SPNs) in thin (200-300 microns) transverse spinal cord slices of neonatal rats (1-14 days postnatal). Exogenous application of glutamate (100 microM), N-methyl-D-aspartate (NMDA; 100 microM), kainate (100 microM), quisqualate (1 microM), and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA; 50 microM) induced inward currents at a holding potential of -30 mV. 2. Excitatory postsynaptic currents (EPSCs) were evoked by electrical stimulation either in the dorsal horn or the lateral funiculus. They reversed at 1.2 +/- 4.6 (SD) mV and could in most cases (49 of 51) be separated into two components. 3. In the presence of DL-2-amino-5-phosphonovalerate (10-40 microM) the current-voltage (I-V) relationship of the remaining EPSC was linear. When stimulated in the lateral funiculus, its rise time (10-90%) and the time constant of the monoexponential decay were 1.6 +/- 1.0 and 5.5 +/- 2.7 ms, respectively. By contrast, when stimulated in the dorsal horn, this component had a rise time (10-90%) of 3.0 +/- 0.8 ms and a decay time constant of 13.7 +/- 7.6 ms. 4. We studied the NMDA receptor-mediated component of the EPSCs after superfusion of 6-cyano-7-nitroquinoxaline-2,3-dione (5 microM). The I-V relationship of this component had a region of negative slope conductance between -30 and -80 mV, which was abolished in Mg(2+)-free saline. The rise time (10-90%) ranged from 3.3 to 9.5 ms and the decay was biexponential. Both decay time constants increased with depolarization. Mg(2+)-free saline reduced this voltage sensitivity. 5. At a membrane potential of -80 mV and in 1 mM extracellular Mg2+, the NMDA receptor-mediated component represented 74.8 +/- 11.2% of the total charge carried by the EPSCs evoked by stimulation in the dorsal horn. In contrast, when stimulated from the lateral funiculus, 28.9 +/- 18.9% of the total charge carried during the EPSC was mediated by the NMDA receptor-mediated component. The contribution of the NMDA receptor-mediated component increased in both cases with depolarization. In addition, in 2 of 18 SPNs the EPSC evoked in the dorsal horn was exclusively carried by NMDA receptors. 6. We conclude that L-glutamate or a related substance mediates the fast excitatory input onto SPNs. Viscerosomatic and supraspinal inputs form synapses with different topographical locations on the SPN.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- J Krupp
- Institut de Physiologie Générale, Université Louis Pasteur, Strasbourg, France
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Abstract
The characteristics of glycinergic inhibitory postsynaptic currents (IPSCs) in sympathetic preganglionic neurons (SPNs) of neonatal rats were studied by whole-cell recordings in transverse spinal cord slices. In relation to postnatal age, the decay time constants of these currents decreased without a comparable effect on their rise time. This may result from alpha-subunit switching of the glycine receptor and/or increased glycine uptake during this period of postnatal life. The kinetics of glycinergic IPSCs were also temperature- and voltage-dependent. Whereas, compared with room temperature, rise and decay of the events were faster at more physiological temperature, only the decay increased upon depolarization. Visual identification of SPNs was confirmed by intracellular staining and comparison with retrogradely labeled SPNs.
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Affiliation(s)
- J Krupp
- Institut de Physiologie Générale, URA 1446 CNRS, Universitè Louis Pasteur, Strasbourg, France
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Abstract
1. By using the whole-cell recording configuration of the patch-clamp technique in a spinal cord slice preparation, we have made recordings from visually identified neurones in the lateral horn of the thoracic and lumbar spinal cord of neonatal rats (newborn to 14 days postnatal). 2. Some of the recorded neurones were labelled with the fluorescent dye Lucifer Yellow (n = 27). Their morphology was typical for sympathetic preganglionic neurones (SPNs). Based on the size of the cell soma and the electrophysiological properties, unlabelled neurones were also regarded as SPNs. 3. Spontaneous synaptic activity of different patterns could be observed in 73% of the recorded neurones (n = 106). It reversed at the chloride equilibrium potential (ECl) and could be reversibly blocked by strychnine (1-10 microM), but not by bicuculline (10 microM) or SR95531 (5-10 microM). 4. Synaptic activity could be elicited by focal electrical stimulation in the vicinity of the recorded neurone. These evoked synaptic events exhibited features similar to the spontaneous synaptic activity. 5. Application of glycine (100 microM-1 mM) by a fast microperfusion system induced a chloride current in twenty-seven out of thirty cells tested. The currents were reversibly blocked by strychnine (1-10 microM), but were only weakly sensitive to bicuculline (10 microM). Stability of current responses to glycine was increased by inclusion of ATP (4 mM) in the intracellular medium. 6. Application of gamma-aminobutyric acid (GABA; 100 microM-1 mM) by the fast microperfusion system induced a chloride current in all twenty neurones tested. These currents were reversibly blocked by bicuculline (10 microM). Strychnine (1-10 microM) blocked this current only weakly. Run-down of GABA-induced currents was prevented to a great extent by inclusion of ATP (4 mM) in the pipette. 7. These results suggest that the inhibitory synaptic activity recorded from SPNs in thin, transverse slices of neonatal rat spinal cord is mediated by glycine receptor-gated Cl- channels. GABAA receptor-gated Cl- channels might be activated by inputs from other spinal segments and/or descending pathways from higher brain regions.
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Affiliation(s)
- J Krupp
- Institut de Physiologie (URA 1446 CNRS), Université Louis Pasteur, Strasbourg, France
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35
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Abstract
Varicella-zoster virus (VZV) DNA was detected in mononuclear cells (MNC) of 7 humans with acute zoster 1-23 days after the onset of skin lesions. To further study the interaction of VZV with human MNC, cells obtained from seropositive normal donors were infected with VZV and analyzed for the presence of viral DNA and proteins. VZV-DNA was detected in T, B, and OKM 1 (monocyte-macrophage) positive cells, and virus-specific proteins were demonstrated by indirect immunofluorescence and immunoprecipitation. Hybridization studies revealed that VZV-DNA did not replicate in human MNC.
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Hocker L, Krupp J, Benedek GB, Vournakis J. Observations of self-aggregation and dissociation of E. coli ribosomes by optical mixing spectroscopy. Biopolymers 1973; 12:1677-87. [PMID: 4582232 DOI: 10.1002/bip.1973.360120718] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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