Journal article
Artificial miRNAs mitigate shRNA-mediated toxicity in the brain: Implications for the therapeutic development of RNAi
Proceedings of the National Academy of Sciences - PNAS, Vol.105(15), pp.5868-5873
04/15/2008
DOI: 10.1073/pnas.0801775105
PMCID: PMC2311380
PMID: 18398004
Abstract
Huntington's disease (HD) is a fatal, dominant neurodegenerative disease caused by a polyglutamine repeat expansion in exon 1 of the HD gene, which encodes the huntingtin protein. We and others have shown that RNAi is a candidate therapy for HD because expression of inhibitory RNAs targeting mutant human HD transgenes improved neuropathology and behavioral deficits in HD mouse models. Here, we developed shRNAs targeting conserved sequences in human HD and mouse HD homolog (HDh) mRNAs to initiate preclinical testing in a knockin mouse model of HD. We screened 35 shRNAs
in vitro
and subsequently narrowed our focus to three candidates for
in vivo
testing. Unexpectedly, two active shRNAs induced significant neurotoxicity in mouse striatum, although HDh mRNA expression was reduced to similar levels by all three. Additionally, a control shRNA containing mismatches also induced toxicity, although it did not reduce HDh mRNA expression. Interestingly, the toxic shRNAs generated higher antisense RNA levels, compared with the nontoxic shRNA. These results demonstrate that the robust levels of antisense RNAs emerging from shRNA expression systems can be problematic in the mouse brain. Importantly, when sequences that were toxic in the context of shRNAs were placed into artificial microRNA (miRNA) expression systems, molecular and neuropathological readouts of neurotoxicity were significantly attenuated without compromising mouse HDh silencing efficacy. Thus, miRNA-based approaches may provide more appropriate biological tools for expressing inhibitory RNAs in the brain, the implications of which are crucial to the development of RNAi for both basic biological and therapeutic applications.
Details
- Title: Subtitle
- Artificial miRNAs mitigate shRNA-mediated toxicity in the brain: Implications for the therapeutic development of RNAi
- Creators
- Jodi L McBride - Departments of Internal MedicineRyan L Boudreau - Departments of Internal MedicineScott Q Harper - Departments of Internal MedicinePatrick D Staber - Departments of Internal MedicineAlex Mas Monteys - Departments of Internal MedicineInês Martins - Departments of Internal MedicineBrian L Gilmore - Departments of Internal MedicineHaim Burstein - Targeted Genetics, 1100 Olive Way, Suite 100, Seattle, WA 98101; andRichard W Peluso - Targeted Genetics, 1100 Olive Way, Suite 100, Seattle, WA 98101; andBarry Polisky - Sirna Therapeutics, 1700 Owens Street, San Francisco, CA 94158Barrie J Carter - Targeted Genetics, 1100 Olive Way, Suite 100, Seattle, WA 98101; andBeverly L Davidson - Departments of Internal Medicine
- Resource Type
- Journal article
- Publication Details
- Proceedings of the National Academy of Sciences - PNAS, Vol.105(15), pp.5868-5873
- DOI
- 10.1073/pnas.0801775105
- PMID
- 18398004
- PMCID
- PMC2311380
- NLM abbreviation
- Proc Natl Acad Sci U S A
- ISSN
- 0027-8424
- eISSN
- 1091-6490
- Publisher
- National Academy of Sciences
- Language
- English
- Date published
- 04/15/2008
- Academic Unit
- Iowa Neuroscience Institute; Cardiovascular Medicine; Fraternal Order of Eagles Diabetes Research Center; Internal Medicine
- Record Identifier
- 9984065385902771
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