title: AAV-mediated overexpression of neuroserpin in the hippocampus decreases PSD-95 expression but does not affect hippocampal-dependent learning and memory.
abstract: Neuroserpin is a serine protease inhibitor, or serpin, that is expressed in the nervous system and inhibits the protease tissue plasminogen activator (tPA). Neuroserpin has been suggested to play a role in learning and memory but direct evidence for such a role is lacking. Here we have used an adeno-associated virus (AAV) vector expression system to investigate the effect of neuroserpin on hippocampal-dependent learning and memory in the young adult rat. A FLAG-tagged neuroserpin construct was initially characterized by in vitro transcription/translation and transfection into HEK293 cells and shown to interact with tPA and be targeted to the secretory pathway. Targeted injection of a chimeric AAV1/2 vector expressing FLAG-neuroserpin resulted in localized overexpression in the dorsal hippocampus. Neuroserpin overexpression led to the appearance of an unstable neuroserpin:tPA complex in zymographic assays consistent with interaction with endogenous tPA in vivo. Rats overexpressing neuroserpin also showed a significant decrease in the levels of postsynaptic density protein 95, a major postsynaptic scaffolding protein. Three weeks after injection, a range of behavioural tests was performed to measure spatial and associative learning and memory, as well as innate and acquired fear. These tests provided no evidence of a role for neuroserpin in hippocampal-dependent learning and memory. In summary this study does not support a role for neuroserpin in hippocampal-dependent learning and memory in young adult rats but does suggest an involvement of neuroserpin in hippocampal synaptic plasticity.
authors.affiliation: School of Biological Sciences, University of Auckland, Auckland, New Zealand; Centre for Brain Research, University of Auckland, Auckland, New Zealand.
authors.forename: Vicky W K
authors.initials: VW
authors.lastname: Tsang
authors.affiliation: Department of Molecular Medicine & Pathology, University of Auckland, Auckland, New Zealand; Department of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand; Centre for Brain Research, University of Auckland, Auckland, New Zealand.
authors.forename: Deborah
authors.initials: D
authors.lastname: Young
authors.affiliation: Department of Molecular Medicine & Pathology, University of Auckland, Auckland, New Zealand; Centre for Brain Research, University of Auckland, Auckland, New Zealand; Department of Molecular Virology, Immunology and Medical Genetics, Ohio State University, Columbus, Ohio, United States of America.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: During
authors.affiliation: School of Biological Sciences, University of Auckland, Auckland, New Zealand; Centre for Brain Research, University of Auckland, Auckland, New Zealand.
authors.forename: Nigel P
authors.initials: NP
authors.lastname: Birch
mesh_terms: D000818:Animals; D001007:Anxiety / Q000378:metabolism; D000229:Dependovirus / Q000378:metabolism*; D000076122:Disks Large Homolog 4 Protein; D005239:Fear; D015870:Gene Expression; D005822:Genetic Vectors / Q000378:metabolism; D057809:HEK293 Cells; D006624:Hippocampus / Q000378:metabolism*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D008568:Memory; D009473:Neuronal Plasticity; D009479:Neuropeptides / Q000378:metabolism*; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism; D017208:Rats, Wistar; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D055571:Secretory Pathway; D015843:Serpins / Q000378:metabolism*; D010959:Tissue Plasminogen Activator / Q000378:metabolism; D014161:Transduction, Genetic; D019076:Transgenes; D000097522:Neuroserpin
chemical_list: D000076122:Disks Large Homolog 4 Protein; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009479:Neuropeptides; D017395:Plasminogen Activator Inhibitor 1; D011993:Recombinant Fusion Proteins; D015843:Serpins; D010959:Tissue Plasminogen Activator; D000097522:Neuroserpin; C501449:Dlg4 protein, rat