title: Convection-enhanced delivery of AAV2-PrPshRNA in prion-infected mice.
abstract: Prion disease is caused by a single pathogenic protein (PrPSc), an abnormal conformer of the normal cellular prion protein PrPC. Depletion of PrPC in prion knockout mice makes them resistant to prion disease. Thus, gene silencing of the Prnp gene is a promising effective therapeutic approach. Here, we examined adeno-associated virus vector type 2 encoding a short hairpin RNA targeting Prnp mRNA (AAV2-PrP-shRNA) to suppress PrPC expression both in vitro and in vivo. AAV2-PrP-shRNA treatment suppressed PrP levels and prevented dendritic degeneration in RML-infected brain aggregate cultures. Infusion of AAV2-PrP-shRNA-eGFP into the thalamus of CD-1 mice showed that eGFP was transported to the cerebral cortex via anterograde transport and the overall PrPC levels were reduced by ∼ 70% within 4 weeks. For therapeutic purposes, we treated RML-infected CD-1 mice with AAV2-PrP-shRNA beginning at 50 days post inoculation. Although AAV2-PrP-shRNA focally suppressed PrPSc formation in the thalamic infusion site by ∼ 75%, it did not suppress PrPSc formation efficiently in other regions of the brain. Survival of mice was not extended compared to the untreated controls. Global suppression of PrPC in the brain is required for successful therapy of prion diseases.
authors.affiliation: Department of Pathology, University of California San Francisco, San Francisco, California, United States of America; Department of Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Misol
authors.initials: M
authors.lastname: Ahn
authors.affiliation: Department of Pathology, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Krystyna
authors.initials: K
authors.lastname: Bajsarowicz
authors.affiliation: Department of Pathology, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Abby
authors.initials: A
authors.lastname: Oehler
authors.affiliation: Department of Pathology, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Azucena
authors.initials: A
authors.lastname: Lemus
authors.affiliation: Department of Neurosurgery and Neurology, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Krystof
authors.initials: K
authors.lastname: Bankiewicz
authors.affiliation: Department of Pathology, University of California San Francisco, San Francisco, California, United States of America; Department of Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: DeArmond
mesh_terms: D000818:Animals; D000229:Dependovirus / Q000235:genetics*; D005260:Female; D055786:Gene Knockout Techniques; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000008:administration & dosage; D051379:Mice; D018621:PrPC Proteins / Q000378:metabolism; D017096:Prion Diseases / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D000072002:Prion Proteins; D011328:Prions / Q000037:antagonists & inhibitors*; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism*; D013788:Thalamus / Q000378:metabolism* / Q000473:pathology
chemical_list: D018621:PrPC Proteins; D000072002:Prion Proteins; D011328:Prions; C512657:Prnp protein, mouse; D034741:RNA, Small Interfering