title: A regulatable AAV vector mediating GDNF biological effects at clinically-approved sub-antimicrobial doxycycline doses.
abstract: Preclinical and clinical data stress the importance of pharmacologically-controlling glial cell line-derived neurotrophic factor (GDNF) intracerebral administration to treat PD. The main challenge is finding a combination of a genetic switch and a drug which, when administered at a clinically-approved dose, reaches the brain in sufficient amounts to induce a therapeutic effect. We describe a highly-sensitive doxycycline-inducible adeno-associated virus (AAV) vector. This vector allowed for the first time a longitudinal analysis of inducible transgene expression in the brain using bioluminescence imaging. To evaluate the dose range of GDNF biological activity, the inducible AAV vector (8.0 × 10(9) viral genomes) was injected in the rat striatum at four delivery sites and increasing doxycycline doses administered orally. ERK/Akt signaling activation as well as tyrosine hydroxylase downregulation, a consequence of long-term GDNF treatment, were induced at plasmatic doxycycline concentrations of 140 and 320 ng/ml respectively, which are known not to increase antibiotic-resistant microorganisms in patients. In these conditions, GDNF covered the majority of the striatum. No behavioral abnormalities or weight loss were observed. Motor asymmetry resulting from unilateral GDNF treatment only appeared with a 2.5-fold higher vector and a 13-fold higher inducer doses. Our data suggest that using the herein-described inducible AAV vector, biological effects of GDNF can be obtained in response to sub-antimicrobial doxycycline doses.
authors.affiliation: Laboratory of Experimental Neurosurgery and Multidisciplinary Research Institute (I.R.I.B.H.M.), Université Libre de Bruxelles (ULB) , Brussel, Belgium.
authors.forename: Abdelwahed
authors.initials: A
authors.lastname: Chtarto
authors.affiliation: Laboratory of Cellular and Molecular Neurotherapies, Center for Neuroscience Research, Dept of Clinical Neuroscience, Lausanne University Hospital , Lausanne, Switzerland.
authors.forename: Marie
authors.initials: M
authors.lastname: Humbert-Claude
authors.affiliation: Laboratory of Experimental Neurosurgery and Multidisciplinary Research Institute (I.R.I.B.H.M.), Université Libre de Bruxelles (ULB) , Brussel, Belgium.
authors.forename: Olivier
authors.initials: O
authors.lastname: Bockstael
authors.affiliation: Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam , Amsterdam, The Netherlands.
authors.forename: Atze T
authors.initials: AT
authors.lastname: Das
authors.affiliation: Center for Microscopy and Molecular Imaging (CMMI) , Charleroi, Belgium.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Boutry
authors.affiliation: CNS Gene Therapy Unit, Department of Experimental Medical Sciences, Wallenberg Neuroscience Center, Lund University , Lund, Sweden.
authors.forename: Ludivine S
authors.initials: LS
authors.lastname: Breger
authors.affiliation: Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam , Amsterdam, The Netherlands.
authors.forename: Bep
authors.initials: B
authors.lastname: Klaver
authors.affiliation: Laboratory of Experimental Neurosurgery and Multidisciplinary Research Institute (I.R.I.B.H.M.), Université Libre de Bruxelles (ULB) , Brussel, Belgium.
authors.forename: Catherine
authors.initials: C
authors.lastname: Melas
authors.affiliation: Departamento de Ciencias Médicas Básicas (Anatomía), Facultad de Ciencias de la Salud (Medicina), Instituto de Tecnologías Biomédicas (ITB, CIBICAN), Universidad de La Laguna , Tenerife, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Barroso-Chinea
authors.affiliation: Departamento de Ciencias Médicas Básicas (Anatomía), Facultad de Ciencias de la Salud (Medicina), Instituto de Tecnologías Biomédicas (ITB, CIBICAN), Universidad de La Laguna , Tenerife, Spain.
authors.forename: Tomas
authors.initials: T
authors.lastname: Gonzalez-Hernandez
authors.affiliation: Department of General, Organic and Biomedical Chemistry, NMR and Molecular Imaging Laboratory, University of Mons , Mons, Belgium.
authors.forename: Robert N
authors.initials: RN
authors.lastname: Muller
authors.affiliation: Neurosurgery, Hôpital Erasme , Brussels, Belgium.
authors.forename: Olivier
authors.initials: O
authors.lastname: DeWitte
authors.affiliation: Neurosurgery unit, Department of Clinical Neuroscience, Lausanne University Hospital , Lausanne, Switzerland.
authors.forename: Marc
authors.initials: M
authors.lastname: Levivier
authors.affiliation: CNS Gene Therapy Unit, Department of Experimental Medical Sciences, Wallenberg Neuroscience Center, Lund University , Lund, Sweden.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Lundberg
authors.affiliation: Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam , Amsterdam, The Netherlands.
authors.forename: Ben
authors.initials: B
authors.lastname: Berkhout
authors.affiliation: Laboratory of Cellular and Molecular Neurotherapies, Center for Neuroscience Research, Dept of Clinical Neuroscience, Lausanne University Hospital , Lausanne, Switzerland.
authors.forename: Liliane
authors.initials: L
authors.lastname: Tenenbaum