title: Silencing Status Epilepticus-Induced BDNF Expression with Herpes Simplex Virus Type-1 Based Amplicon Vectors.
abstract: Brain-derived neurotrophic factor (BDNF) has been found to produce pro- but also anti-epileptic effects. Thus, its validity as a therapeutic target must be verified using advanced tools designed to block or to enhance its signal. The aim of this study was to develop tools to silence the BDNF signal. We generated Herpes simplex virus type 1 (HSV-1) derived amplicon vectors, i.e. viral particles containing a genome of 152 kb constituted of concatameric repetitions of an expression cassette, enabling the expression of the gene of interest in multiple copies. HSV-1 based amplicon vectors are non-pathogenic and have been successfully employed in the past for gene delivery into the brain of living animals. Therefore, amplicon vectors should represent a logical choice for expressing a silencing cassette, which, in multiple copies, is expected to lead to an efficient knock-down of the target gene expression. Here, we employed two amplicon-based BDNF silencing strategies. The first, antisense, has been chosen to target and degrade the cytoplasmic mRNA pool of BDNF, whereas the second, based on the convergent transcription technology, has been chosen to repress transcription at the BDNF gene. Both these amplicon vectors proved to be effective in down-regulating BDNF expression in vitro, in BDNF-expressing mesoangioblast cells. However, only the antisense strategy was effective in vivo, after inoculation in the hippocampus in a model of status epilepticus in which BDNF mRNA levels are strongly increased. Interestingly, the knocking down of BDNF levels induced with BDNF-antisense was sufficient to produce significant behavioral effects, in spite of the fact that it was produced only in a part of a single hippocampus. In conclusion, this study demonstrates a reliable effect of amplicon vectors in knocking down gene expression in vitro and in vivo. Therefore, this approach may find broad applications in neurobiological studies.
authors.affiliation: Department of Medical Science, Section of Pharmacology, Neuroscience Center, University of Ferrara and National Institute of Neuroscience, Ferrara, Italy.|Bioviron, Université Claude Bernard Lyon 1, Villeurbanne, France.
authors.forename: Chiara
authors.initials: C
authors.lastname: Falcicchia
authors.affiliation: Department of Medical Science, Section of Pharmacology, Neuroscience Center, University of Ferrara and National Institute of Neuroscience, Ferrara, Italy.|Bioviron, Université Claude Bernard Lyon 1, Villeurbanne, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Trempat
authors.affiliation: Department of Medical Science, Section of Pharmacology, Neuroscience Center, University of Ferrara and National Institute of Neuroscience, Ferrara, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Binaschi
authors.affiliation: Bioviron, Université Claude Bernard Lyon 1, Villeurbanne, France.
authors.forename: Coline
authors.initials: C
authors.lastname: Perrier-Biollay
authors.affiliation: Department of Medical Science, Section of Pharmacology, Neuroscience Center, University of Ferrara and National Institute of Neuroscience, Ferrara, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Roncon
authors.affiliation: Department of Medical Science, Section of Pharmacology, Neuroscience Center, University of Ferrara and National Institute of Neuroscience, Ferrara, Italy.
authors.forename: Marie
authors.initials: M
authors.lastname: Soukupova
authors.affiliation: Bioviron, Université Claude Bernard Lyon 1, Villeurbanne, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Berthommé
authors.affiliation: Department of Medical Science, Section of Pharmacology, Neuroscience Center, University of Ferrara and National Institute of Neuroscience, Ferrara, Italy.|Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, Ferrara, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Simonato
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D016373:DNA, Antisense / Q000235:genetics; D004195:Disease Models, Animal; D015870:Gene Expression; D023061:Gene Order; D020868:Gene Silencing; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000008:administration & dosage / Q000235:genetics*; D018259:Herpesvirus 1, Human / Q000235:genetics*; D006624:Hippocampus / Q000378:metabolism; D006801:Humans; D008297:Male; D010957:Plasmids / Q000235:genetics; D051381:Rats; D013226:Status Epilepticus / Q000188:drug therapy / Q000235:genetics*; D019076:Transgenes; D014709:Vero Cells
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D016373:DNA, Antisense