title: Adenosine kinase, glutamine synthetase and EAAT2 as gene therapy targets for temporal lobe epilepsy.
abstract: Astrocytes are an attractive cell target for gene therapy, but the validation of new therapeutic candidates is needed. We determined whether adeno-associated viral (AAV) vector-mediated overexpression of glutamine synthetase (GS) or excitatory amino-acid transporter 2 (EAAT2), or expression of microRNA targeting adenosine kinase (miR-ADK) in hippocampal astrocytes in the rat brain could modulate susceptibility to kainate-induced seizures and neuronal cell loss. Transgene expression was found predominantly in astrocytes following direct injection of glial-targeting AAV9 vectors by 3 weeks postinjection. ADK expression in miR-ADK vector-injected rats was reduced by 94-96% and was associated with an ~50% reduction in the duration of kainate-induced seizures and greater protection of dentate hilar neurons but not CA3 neurons compared with miR-control vector-injected rats. In contrast, infusion of AAV-GS and EAAT2 vectors did not afford any protection against seizures or neuronal damage as the level of transcriptional activity of the glial fibrillary acidic promoter was too low to drive any significant increase in transgenic GS or EAAT2 relative to the high endogenous levels of these proteins. Our findings support ADK as a prime therapeutic target for gene therapy of temporal lobe epilepsy and suggest that alternative approaches including the use of stronger glial promoters are needed to increase transgenic GS and EAAT2 expression to levels that may be required to affect seizure induction and propagation.
authors.affiliation: 1] Departments of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand [2] Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand [3] Centre for Brain Research, University of Auckland, Auckland, New Zealand.
authors.forename: D
authors.initials: D
authors.lastname: Young
authors.affiliation: 1] Departments of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand [2] Centre for Brain Research, University of Auckland, Auckland, New Zealand.
authors.forename: D M
authors.initials: DM
authors.lastname: Fong
authors.affiliation: 1] Departments of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand [2] Centre for Brain Research, University of Auckland, Auckland, New Zealand.
authors.forename: P A
authors.initials: PA
authors.lastname: Lawlor
authors.affiliation: 1] Departments of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand [2] Centre for Brain Research, University of Auckland, Auckland, New Zealand.
authors.forename: A
authors.initials: A
authors.lastname: Wu
authors.affiliation: 1] Departments of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand [2] Centre for Brain Research, University of Auckland, Auckland, New Zealand.
authors.forename: A
authors.initials: A
authors.lastname: Mouravlev
authors.affiliation: 1] Departments of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand [2] Centre for Brain Research, University of Auckland, Auckland, New Zealand.
authors.forename: M
authors.initials: M
authors.lastname: McRae
authors.affiliation: 1] Departments of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand [2] Centre for Brain Research, University of Auckland, Auckland, New Zealand.
authors.forename: M
authors.initials: M
authors.lastname: Glass
authors.affiliation: 1] Departments of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand [2] Centre for Brain Research, University of Auckland, Auckland, New Zealand.
authors.forename: M
authors.initials: M
authors.lastname: Dragunow
authors.affiliation: 1] Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand [2] Centre for Brain Research, University of Auckland, Auckland, New Zealand [3] Department of Molecular Virology, Immunology and Medical Genetics, Neuroscience and Neurological Surgery, Ohio State University, Columbus, OH, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: During
mesh_terms: D000248:Adenosine Kinase / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D004833:Epilepsy, Temporal Lobe / Q000628:therapy*; D027342:Excitatory Amino Acid Transporter 2 / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D018390:Gene Targeting; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D005974:Glutamate-Ammonia Ligase / Q000235:genetics* / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism; D007608:Kainic Acid / Q000009:adverse effects; D008297:Male; D009457:Neuroglia / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012640:Seizures / Q000139:chemically induced; D019076:Transgenes / Q000235:genetics
chemical_list: D027342:Excitatory Amino Acid Transporter 2; D000248:Adenosine Kinase; D005974:Glutamate-Ammonia Ligase; D007608:Kainic Acid