title: Rapid transgene expression in multiple precursor cell types of adult rat subventricular zone mediated by adeno-associated type 1 vectors.
abstract: The adult rat brain subventricular zone (SVZ) contains proliferative precursors that migrate to the olfactory bulb (OB) and differentiate into mature neurons. Recruitment of precursors constitutes a potential avenue for brain repair. We have investigated the kinetics and cellular specificity of transgene expression mediated by AAV2/1 vectors (i.e., adeno-associated virus type 2 pseudotyped with AAV1 capsid) in the SVZ. Self-complementary (sc) and single-stranded (ss) AAV2/1 vectors mediated efficient GFP expression, respectively, at 17 and 24 hr postinjection. Transgene expression was efficient in all the rapidly proliferating cells types, that is, Mash1(+) precursors (30% of the GFP(+) cells), Dlx2(+) neuronal progenitors (55%), Olig2(+) oligodendrocyte progenitors (35%), and doublecortin-positive (Dcx(+)) migrating cells (40%), but not in the slowly proliferating glial fibrillary acidic protein-positive (GFAP(+)) neural stem cell pool (5%). Because cell cycle arrest by wild-type and recombinant AAV has been described in primary cultures, we examined SVZ proliferative activity after vector injection. Indeed, cell proliferation was reduced immediately after vector injection but was normal after 1 month. In contrast, migration and differentiation of GFP(+) precursors were unaltered. Indeed, the proportion of Dcx(+) cells was similar in the injected and contralateral hemispheres. Furthermore, 1 month after vector injection into the SVZ, GFP(+) cells, found, as expected, in the OB granular cell layer, were mature GABAergic neurons. In conclusion, the rapid and efficient transgene expression in SVZ neural precursors mediated by scAAV2/1 vectors underlines their potential usefulness for brain repair via recruitment of immature cells. The observed transient precursor proliferation inhibition, not affecting their migration and differentiation, will likely not compromise this strategy.
authors.affiliation: Laboratory of Experimental Neurosurgery, Université Libre de Bruxelles, BE-1070 Brussels, Belgium. olivier.bockstael@ulb.ac.be
authors.forename: Olivier
authors.initials: O
authors.lastname: Bockstael
authors.forename: Catherine
authors.initials: C
authors.lastname: Melas
authors.forename: Catherine
authors.initials: C
authors.lastname: Pythoud
authors.forename: Marc
authors.initials: M
authors.lastname: Levivier
authors.forename: Douglas
authors.initials: D
authors.lastname: McCarty
authors.forename: R Jude
authors.initials: RJ
authors.lastname: Samulski
authors.forename: Olivier
authors.initials: O
authors.lastname: De Witte
authors.forename: Liliane
authors.initials: L
authors.lastname: Tenenbaum
mesh_terms: D000818:Animals; D017209:Apoptosis; D001921:Brain; D002454:Cell Differentiation; D002465:Cell Movement; D049109:Cell Proliferation; D002552:Cerebral Ventricles / Q000166:cytology / Q000378:metabolism*; D000229:Dependovirus / Q000235:genetics*; D000089662:Doublecortin Protein; D005260:Female; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics; D057809:HEK293 Cells; D018398:Homeodomain Proteins / Q000378:metabolism; D006801:Humans; D058953:Neural Stem Cells / Q000378:metabolism* / Q000502:physiology; D009830:Olfactory Bulb / Q000166:cytology; D051381:Rats; D017208:Rats, Wistar; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism; D014161:Transduction, Genetic; D019076:Transgenes
chemical_list: C000714848:Dcx protein, rat; C088334:Distal-less homeobox proteins; D000089662:Doublecortin Protein; D018398:Homeodomain Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; D049452:Green Fluorescent Proteins