Effects of AAV-mediated knockdown of nNOS and GPx-1 gene expression in rat hippocampus after traumatic brain injury

Deborah R. Boone, Jeanna M. Leek, Michael T. Falduto, Karen E.O. Torres, Stacy Sell, Margaret A. Parsley, Jeremy C. Cowart, Tatsuo Uchida, Maria Micci, Douglas Dewitt, Donald Prough, Helen Hellmich

Research output: Contribution to journalArticle

3 Scopus citations

Abstract

Virally mediated RNA interference (RNAi) to knock down injury-induced genes could improve functional outcome after traumatic brain injury (TBI); however, little is known about the consequences of gene knockdown on downstream cell signaling pathways and how RNAi influences neurodegeneration and behavior. Here, we assessed the effects of adeno-associated virus (AAV) siRNA vectors that target two genes with opposing roles in TBI pathogenesis: the allegedly detrimental neuronal nitric oxide synthase (nNOS) and the potentially protective glutathione peroxidase 1 (GPx-1). In rat hippocampal progenitor cells, three siRNAs that target different regions of each gene (nNOS, GPx-1) effectively knocked down gene expression. However, in vivo, in our rat model of fluid percussion brain injury, the consequences of AAV-siRNA were variable. One nNOS siRNA vector significantly reduced the number of degenerating hippocampal neurons and showed a tendency to improve working memory. GPx-1 siRNA treatment did not alter TBI-induced neurodegeneration or working memory deficits. Nevertheless, microarray analysis of laser captured, virus-infected neurons showed that knockdown of nNOS or GPx-1 was specific and had broad effects on downstream genes. Since nNOS knockdown only modestly ameliorated TBI-induced working memory deficits, despite widespread genomic changes, manipulating expression levels of single genes may not be sufficient to alter functional outcome after TBI.

Original languageEnglish (US)
Article numbere0185943
JournalPLoS One
Volume12
Issue number10
DOIs
StatePublished - Oct 1 2017

    Fingerprint

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

Cite this