title: Botulinum toxin induces muscle paralysis and inhibits bone regeneration in zebrafish.
abstract: Intramuscular administration of Botulinum toxin (BTx) has been associated with impaired osteogenesis in diverse conditions of bone formation (eg, development, growth, and healing), yet the mechanisms of neuromuscular-bone crosstalk underlying these deficits have yet to be identified. Motivated by the emerging utility of zebrafish (Danio rerio) as a rapid, genetically tractable, and optically transparent model for human pathologies (as well as the potential to interrogate neuromuscular-mediated bone disorders in a simple model that bridges in vitro and more complex in vivo model systems), in this study, we developed a model of BTx-induced muscle paralysis in adult zebrafish, and we examined its effects on intramembranous ossification during tail fin regeneration. BTx administration induced rapid muscle paralysis in adult zebrafish in a manner that was dose-dependent, transient, and focal, mirroring the paralytic phenotype observed in animal and human studies. During fin regeneration, BTx impaired continued bone ray outgrowth, morphology, and patterning, indicating defects in early osteogenesis. Further, BTx significantly decreased mineralizing activity and crystalline mineral accumulation, suggesting delayed late-stage osteoblast differentiation and/or altered secondary bone apposition. Bone ray transection proximal to the amputation site focally inhibited bone outgrowth in the affected ray, implicating intra- and/or inter-ray nerves in this process. Taken together, these studies demonstrate the potential to interrogate pathological features of BTx-induced osteoanabolic dysfunction in the regenerating zebrafish fin, define the technological toolbox for detecting bone growth and mineralization deficits in this process, and suggest that pathways mediating neuromuscular regulation of osteogenesis may be conserved beyond established mammalian models of bone anabolic disorders.
authors.affiliation: Department of Orthopaedics and Sports Medicine, University of Washington, Seattle, WA, USA.
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Recidoro
authors.forename: Amanda C
authors.initials: AC
authors.lastname: Roof
authors.forename: Michael
authors.initials: M
authors.lastname: Schmitt
authors.forename: Leah E
authors.initials: LE
authors.lastname: Worton
authors.forename: Timothy
authors.initials: T
authors.lastname: Petrie
authors.forename: Nicholas
authors.initials: N
authors.lastname: Strand
authors.forename: Brandon J
authors.initials: BJ
authors.lastname: Ausk
authors.forename: Sundar
authors.initials: S
authors.lastname: Srinivasan
authors.forename: Randall T
authors.initials: RT
authors.lastname: Moon
authors.forename: Edith M
authors.initials: EM
authors.lastname: Gardiner
authors.forename: Werner
authors.initials: W
authors.lastname: Kaminsky
authors.forename: Steven D
authors.initials: SD
authors.lastname: Bain
authors.forename: Christopher H
authors.initials: CH
authors.lastname: Allan
authors.forename: Ted S
authors.initials: TS
authors.lastname: Gross
authors.forename: Ronald Y
authors.initials: RY
authors.lastname: Kwon
mesh_terms: D000328:Adult; D000818:Animals; D001861:Bone Regeneration / Q000187:drug effects*; D001905:Botulinum Toxins / Q000633:toxicity*; D002113:Calcification, Physiologic / Q000187:drug effects*; D002454:Cell Differentiation / Q000187:drug effects; D004195:Disease Models, Animal; D006801:Humans; D010006:Osteoblasts / Q000378:metabolism / Q000473:pathology; D010012:Osteogenesis / Q000187:drug effects*; D010243:Paralysis / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D015027:Zebrafish / Q000378:metabolism*
chemical_list: D001905:Botulinum Toxins
keywords: Animal Models; Bone Modeling and Remodeling; Bone-Brain-Nervous System Interactions; Osteoblasts; Skeletal Muscle