title: C3 transferase gene therapy for continuous conditional RhoA inhibition.
abstract: Regrowth inhibitory molecules prevent axon regeneration in the adult mammalian central nervous system (CNS). RhoA, a small GTPase in the Rho family, is a key intracellular switch that mediates the effects of these extracellular regrowth inhibitors. The bacterial enzyme C3-ADP ribosyltransferase (C3) selectively and irreversibly inhibits the activation of RhoA and stimulates axon outgrowth and regeneration. However, effective intracellular delivery of the C3 protein in vivo is limited by poor cell permeability and a short duration of action. To address this, we have developed a gene therapy approach using viral vectors to introduce the C3 gene into neurons or neuronal progenitors. Our vectors deliver C3 in a cell-autonomous (endogenous) or a cell-nonautonomous (secretable/permeable) fashion and promote in vitro process outgrowth on inhibitory chondroitin sulfate proteoglycan substrate. Further conditional control of our vectors was achieved via the addition of a Tet-On system, which allows for transcriptional control with doxycycline administration. These vectors will be crucial tools for promoting continued axonal regeneration after CNS injuries or neurodegenerative diseases.
authors.affiliation: Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, United States. Electronic address: cguteku@emory.edu.
authors.forename: Claire-Anne
authors.initials: CA
authors.lastname: Gutekunst
authors.affiliation: Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, United States; Wallace H. Coulter Department of Biomedical Engineering, Emory University School of Medicine and Georgia Institute of Technology College of Engineering, Atlanta, GA, United States. Electronic address: jtung@emory.edu.
authors.forename: Jack K
authors.initials: JK
authors.lastname: Tung
authors.affiliation: Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, United States. Electronic address: mmcdoug@emory.edu.
authors.forename: Margaret E
authors.initials: ME
authors.lastname: McDougal
authors.affiliation: Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, United States; Department of Neurology, Emory University School of Medicine, Atlanta, GA, United States; Wallace H. Coulter Department of Biomedical Engineering, Emory University School of Medicine and Georgia Institute of Technology College of Engineering, Atlanta, GA, United States. Electronic address: rgross@emory.edu.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Gross
mesh_terms: D036002:ADP Ribose Transferases / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D001369:Axons / Q000502:physiology*; D001905:Botulinum Toxins / Q000235:genetics* / Q000378:metabolism; D002540:Cerebral Cortex / Q000166:cytology / Q000201:enzymology; D011508:Chondroitin Sulfate Proteoglycans; D003342:Corpus Striatum / Q000166:cytology / Q000201:enzymology; D000229:Dependovirus / Q000235:genetics; D004318:Doxycycline; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors; D057809:HEK293 Cells; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D008297:Male; D051379:Mice; D041681:NIH 3T3 Cells; D009416:Nerve Regeneration; D000071446:Neuronal Outgrowth; D009474:Neurons / Q000166:cytology / Q000201:enzymology; D011897:Random Allocation; D017207:Rats, Sprague-Dawley; D014158:Transcription, Genetic; D020742:rhoA GTP-Binding Protein / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D011508:Chondroitin Sulfate Proteoglycans; D036002:ADP Ribose Transferases; C063007:exoenzyme C3, Clostridium botulinum; D001905:Botulinum Toxins; D020742:rhoA GTP-Binding Protein; D004318:Doxycycline
keywords: C3 transferase; RhoA inhibition; axonal regeneration; central nervous system; gene therapy