title: Phosphatase Inhibitors Function as Novel, Broad Spectrum Botulinum Neurotoxin Antagonists in Mouse and Human Embryonic Stem Cell-Derived Motor Neuron-Based Assays.
abstract: There is an urgent need to develop novel treatments to counter Botulinum neurotoxin (BoNT) poisoning. Currently, the majority of BoNT drug development efforts focus on directly inhibiting the proteolytic components of BoNT, i.e. light chains (LC). Although this is a rational approach, previous research has shown that LCs are extremely difficult drug targets and that inhibiting multi-serotype BoNTs with a single LC inhibitor may not be feasible. An alternative approach would target neuronal pathways involved in intoxication/recovery, rather than the LC itself. Phosphorylation-related mechanisms have been implicated in the intoxication pathway(s) of BoNTs. However, the effects of phosphatase inhibitors upon BoNT activity in the physiological target of BoNTs, i.e. motor neurons, have not been investigated. In this study, a small library of phosphatase inhibitors was screened for BoNT antagonism in the context of mouse embryonic stem cell-derived motor neurons (ES-MNs). Four inhibitors were found to function as BoNT/A antagonists. Subsequently, we confirmed that these inhibitors protect against BoNT/A in a dose-dependent manner in human ES-MNs. Additionally, these compounds provide protection when administered in post-intoxication scenario. Importantly, the inhibitors were also effective against BoNT serotypes B and E. To the best of our knowledge, this is the first study showing phosphatase inhibitors as broad-spectrum BoNT antagonists.
authors.affiliation: Geneva Foundation, Tacoma, WA, United States of America; Department of Molecular and Translational Sciences, US Army Medical Research Institute of Infectious Diseases, Frederick, MD, United States of America; Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute (NCI), Frederick, MD, United States of America.
authors.forename: Erkan
authors.initials: E
authors.lastname: Kiris
authors.affiliation: Department of Molecular and Translational Sciences, US Army Medical Research Institute of Infectious Diseases, Frederick, MD, United States of America.
authors.forename: Jonathan E
authors.initials: JE
authors.lastname: Nuss
authors.affiliation: Division of Cellular Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA, United States of America.
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: Stanford
authors.affiliation: Department of Molecular and Translational Sciences, US Army Medical Research Institute of Infectious Diseases, Frederick, MD, United States of America.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Wanner
authors.affiliation: Department of Molecular and Translational Sciences, US Army Medical Research Institute of Infectious Diseases, Frederick, MD, United States of America.
authors.forename: Lisa
authors.initials: L
authors.lastname: Cazares
authors.affiliation: Division of Cellular Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA, United States of America.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Maestre
authors.affiliation: Department of Molecular and Translational Sciences, US Army Medical Research Institute of Infectious Diseases, Frederick, MD, United States of America.
authors.forename: Hao T
authors.initials: HT
authors.lastname: Du
authors.affiliation: Department of Molecular and Translational Sciences, US Army Medical Research Institute of Infectious Diseases, Frederick, MD, United States of America.
authors.forename: Glenn Y
authors.initials: GY
authors.lastname: Gomba
authors.affiliation: Leidos Biomedical Research, Inc., Computational Drug Development Group (CDDG), NCI, Frederick, MD, United States of America; CDDG, Developmental Therapeutics Program, NCI, Frederick, MD, United States of America.
authors.forename: James C
authors.initials: JC
authors.lastname: Burnett
authors.affiliation: CDDG, Developmental Therapeutics Program, NCI, Frederick, MD, United States of America.
authors.forename: Rick
authors.initials: R
authors.lastname: Gussio
authors.affiliation: Division of Cellular Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA, United States of America.
authors.forename: Nunzio
authors.initials: N
authors.lastname: Bottini
authors.affiliation: Department of Molecular and Translational Sciences, US Army Medical Research Institute of Infectious Diseases, Frederick, MD, United States of America.
authors.forename: Rekha G
authors.initials: RG
authors.lastname: Panchal
authors.affiliation: Department of Molecular and Translational Sciences, US Army Medical Research Institute of Infectious Diseases, Frederick, MD, United States of America; Henry M. Jackson Foundation, Bethesda, MD, United States of America; DoD Biotechnology High Performance Computing Software Applications Institute (BHSAI), Telemedicine and Advanced Technology Research Center (TATRC), US Army Medical Research and Materiel Command (USAMRMC), Frederick, MD, United States of America.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Kane
authors.affiliation: Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute (NCI), Frederick, MD, United States of America.
authors.forename: Lino
authors.initials: L
authors.lastname: Tessarollo
authors.affiliation: Department of Molecular and Translational Sciences, US Army Medical Research Institute of Infectious Diseases, Frederick, MD, United States of America.
authors.forename: Sina
authors.initials: S
authors.lastname: Bavari
mesh_terms: D000818:Animals; D001905:Botulinum Toxins / Q000037:antagonists & inhibitors / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D053595:Embryonic Stem Cells / Q000187:drug effects* / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D051379:Mice; D009046:Motor Neurons / Q000187:drug effects* / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000037:antagonists & inhibitors; D050600:SNARE Proteins / Q000378:metabolism; D054852:Small Molecule Libraries / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; D050600:SNARE Proteins; D054852:Small Molecule Libraries; D010744:Phosphoric Monoester Hydrolases; D001905:Botulinum Toxins