Adenoviral brain-derived neurotrophic factor induces both neostriatal and olfactory neuronal recruitment from endogenous progenitor cells in the adult forebrain.
Neural progenitor cells persist throughout the adult forebrain subependyma, and neurons generated from them respond to brain-derived neurotrophic factor (BDNF) with enhanced maturation and survival. To induce neurogenesis from endogenous progenitors, we overexpressed BDNF in the adult ventricular zone by transducing the forebrain ependyma to constitutively express BDNF. We constructed a bicistronic adenovirus bearing BDNF under cytomegalovirus (CMV) control, and humanized green fluorescent protein (hGFP) under internal ribosomal entry site (IRES) control. This AdCMV:BDNF:IRES:hGFP (AdBDNF) was injected into the lateral ventricles of adult rats, who were treated for 18 d thereafter with the mitotic marker bromodeoxyuridine (BrdU). Three weeks after injection, BDNF averaged 1 microg/gm in the CSF of AdBDNF-injected animals but was undetectable in control CSF. In situ hybridization demonstrated BDNF and GFP mRNA expression restricted to the ventricular wall. In AdBDNF-injected rats, the olfactory bulb exhibited a >2.4-fold increase in the number of BrdU(+)-betaIII-tubulin(+) neurons, confirmed by confocal imaging, relative to AdNull (AdCMV:hGFP) controls. Importantly, AdBDNF-associated neuronal recruitment to the neostriatum was also noted, with the treatment-induced addition of BrdU(+)-NeuN(+)-betaIII-tubulin(+) neurons to the caudate putamen. Many of these cells also expressed glutamic acid decarboxylase, cabindin-D28, and DARPP-32 (dopamine and cAMP-regulated phosphoprotein of 32 kDa), markers of medium spiny neurons of the neostriatum. These newly generated neurons survived at least 5-8 weeks after viral induction. Thus, a single injection of adenoviral BDNF substantially augmented the recruitment of new neurons into both neurogenic and non-neurogenic sites in the adult rat brain. The intraventricular delivery of, and ependymal infection by, viral vectors encoding neurotrophic agents may be a feasible strategy for inducing neurogenesis from resident progenitor cells in the adult brain.
Benraiss
A
A
Department of Neurology and Neuroscience, Cornell University Medical College, New York, New York 10021, USA.
Chmielnicki
E
E
Lerner
K
K
Roh
D
D
Goldman
S A
SA
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000008:administration & dosage* / Q000096:biosynthesis / Q000235:genetics; D001973:Bromodeoxyuridine; D002452:Cell Count; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D002555:Cerebrospinal Fluid / Q000378:metabolism; D017930:Genes, Reporter; D005822:Genetic Vectors / Q000008:administration & dosage / Q000235:genetics / Q000378:metabolism; D049452:Green Fluorescent Proteins; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007276:Injections, Intraventricular; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000235:genetics; D017072:Neostriatum / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D009830:Olfactory Bulb / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D016548:Prosencephalon / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D014018:Tissue Distribution
D019208:Brain-Derived Neurotrophic Factor; D008164:Luminescent Proteins; D012333:RNA, Messenger; D049452:Green Fluorescent Proteins; D001973:Bromodeoxyuridine