title: The dynein inhibitor Ciliobrevin D inhibits the bidirectional transport of organelles along sensory axons and impairs NGF-mediated regulation of growth cones and axon branches.
abstract: The axonal transport of organelles is critical for the development, maintenance, and survival of neurons, and its dysfunction has been implicated in several neurodegenerative diseases. Retrograde axon transport is mediated by the motor protein dynein. In this study, using embryonic chicken dorsal root ganglion neurons, we investigate the effects of Ciliobrevin D, a pharmacological dynein inhibitor, on the transport of axonal organelles, axon extension, nerve growth factor (NGF)-induced branching and growth cone expansion, and axon thinning in response to actin filament depolymerization. Live imaging of mitochondria, lysosomes, and Golgi-derived vesicles in axons revealed that both the retrograde and anterograde transport of these organelles was inhibited by treatment with Ciliobrevin D. Treatment with Ciliobrevin D reversibly inhibits axon extension and transport, with effects detectable within the first 20 min of treatment. NGF induces growth cone expansion, axonal filopodia formation and branching. Ciliobrevin D prevented NGF-induced formation of axonal filopodia and branching but not growth cone expansion. Finally, we report that the retrograde reorganization of the axonal cytoplasm which occurs on actin filament depolymerization is inhibited by treatment with Ciliobrevin D, indicating a role for microtubule based transport in this process, as well as Ciliobrevin D accelerating Wallerian degeneration. This study identifies Ciliobrevin D as an inhibitor of the bidirectional transport of multiple axonal organelles, indicating this drug may be a valuable tool for both the study of dynein function and a first pass analysis of the role of axonal transport.
authors.affiliation: Department of Anatomy and Cell Biology, Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, 3500 N Broad St, Philadelphia, Pennsylvania, 19140.
authors.forename: Rajiv
authors.initials: R
authors.lastname: Sainath
authors.affiliation: Department of Anatomy and Cell Biology, Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, 3500 N Broad St, Philadelphia, Pennsylvania, 19140.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Gallo
mesh_terms: D008841:Actin Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001369:Axons / Q000187:drug effects* / Q000502:physiology; D001692:Biological Transport / Q000187:drug effects; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D002478:Cells, Cultured; D002642:Chick Embryo; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism; D004398:Dyneins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D005727:Ganglia, Spinal / Q000187:drug effects / Q000502:physiology; D020439:Growth Cones / Q000187:drug effects* / Q000502:physiology; D020932:Nerve Growth Factor / Q000378:metabolism; D015388:Organelles / Q000187:drug effects* / Q000378:metabolism; D052999:Quinazolinones / Q000494:pharmacology*; D011984:Sensory Receptor Cells / Q000187:drug effects* / Q000502:physiology; D053778:Thiazolidines / Q000494:pharmacology; D046509:Tissue Culture Techniques; D014855:Wallerian Degeneration / Q000378:metabolism
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D052999:Quinazolinones; D053778:Thiazolidines; C000595851:ciliobrevin D; D020932:Nerve Growth Factor; D004398:Dyneins; C037067:latrunculin A
keywords: Ciliobrevin D; Golgi derived vesicles; Wallerian degeneration; axon branching; axon growth; axon transport; dynein; kinesin; latrunculin; lysosome; mitochondria; p150glued dynactin; tubulin acetylation; tubulin tyrosination