title: Behavioral and cellular protection of rat dopaminergic neurons by an adenoviral vector encoding glial cell line-derived neurotrophic factor.
abstract: Previously, we observed that an adenoviral (Ad) vector encoding human glial cell line-derived neurotrophic factor (GDNF), injected near the rat substantia nigra (SN), protects SN dopaminergic (DA) neuronal soma from 6-hydroxydopamine (6-OHDA)-induced degeneration. In the present study, the effects of Ad GDNF injected into the striatum, the site of DA nerve terminals, were assessed in the same lesion model. So that effects on cell survival could be assessed without relying on DA phenotypic markers, fluorogold (FG) was infused bilaterally into striatae to retrogradely label DA neurons. Ad GDNF or control treatment (Ad mGDNF, encoding a deletion mutant GDNF, Ad lacZ, vehicle, or no injection) was injected unilaterally into the striatum near one FG site. Progressive degeneration of DA neurons was initiated 7 days later by unilateral injection of 6-OHDA at this FG site. At 42 days after 6-OHDA, Ad GDNF prevented the death of 40% of susceptible DA neurons that projected to the lesion site. Ad GDNF prevented the development of behavioral asymmetries which depend on striatal dopamine, including limb use asymmetries during spontaneous movements along vertical surfaces and amphetamine-induced rotation. Both behavioral asymmetries were exhibited by control-treated, lesioned rats. Interestingly, these behavioral protections occurred in the absence of an increase in the density of DA nerve fibers in the striatum of Ad GDNF-treated rats. ELISA measurements of transgene proteins showed that nanogram quantities of GDNF and lacZ transgene were present in the striatum for 7 weeks, and picogram quantities of GDNF in the SN due to retrograde transport of vector and/or transgene protein. These studies demonstrate that Ad GDNF can sustain increased levels of biosynthesized GDNF in the terminal region of DA neurons for at least 7 weeks and that this GDNF slows the degeneration of DA neurons and prevents the appearance of dopamine dependent motor asymmetries in a rat model of Parkinson's disease (PD). GDNF gene therapy targeted to the striatum, a more surgically accessible site than the SN, may be clinically applicable to humans with PD.
authors.affiliation: Department of Neurobiology and Anatomy, University of Rochester, School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, New York, 14642, USA. dlcl@gene.com
authors.forename: D L
authors.initials: DL
authors.lastname: Choi-Lundberg
authors.forename: Q
authors.initials: Q
authors.lastname: Lin
authors.forename: T
authors.initials: T
authors.lastname: Schallert
authors.forename: D
authors.initials: D
authors.lastname: Crippens
authors.forename: B L
authors.initials: BL
authors.lastname: Davidson
authors.forename: Y N
authors.initials: YN
authors.lastname: Chang
authors.forename: Y L
authors.initials: YL
authors.lastname: Chiang
authors.forename: J
authors.initials: J
authors.lastname: Qian
authors.forename: L
authors.initials: L
authors.lastname: Bardwaj
authors.forename: M C
authors.initials: MC
authors.lastname: Bohn
mesh_terms: D000256:Adenoviridae; D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001835:Body Weight; D002470:Cell Survival / Q000502:physiology; D003342:Corpus Striatum / Q000502:physiology; D004279:DNA, Viral / Q000032:analysis; D004298:Dopamine / Q000502:physiology*; D015259:Dopamine Agents / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D015316:Genetic Therapy; D051100:Glial Cell Line-Derived Neurotrophic Factor; D006801:Humans; D007763:Lac Operon; D008297:Male; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins / Q000235:genetics*; D009474:Neurons / Q000166:cytology* / Q000821:virology; D018696:Neuroprotective Agents / Q000378:metabolism*; D016627:Oxidopamine; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D011916:Rats, Inbred F344; D011994:Recombinant Proteins / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013378:Substantia Nigra / Q000502:physiology; D013565:Sympatholytics; D019076:Transgenes / Q000502:physiology
chemical_list: D004279:DNA, Viral; D015259:Dopamine Agents; C495039:GDNF protein, human; C495041:Gdnf protein, rat; D051100:Glial Cell Line-Derived Neurotrophic Factor; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D018696:Neuroprotective Agents; D012333:RNA, Messenger; D011994:Recombinant Proteins; D013565:Sympatholytics; D016627:Oxidopamine; D000661:Amphetamine; D004298:Dopamine