RNA interference (RNAi) is a widespread gene-silencing phenomenon initiated by a double-stranded RNA that is converted into small interfering RNAs (siRNAs). Although the detailed mechanism whereby siRNA silences its target gene expression is not understood, it has been well established that siRNA associates with an RNAinduced silencing complex (RiSe) to form an RNA-protein complex that can recognize and cleave an mRNA target that complements the siRNA sequence. We would like to understand the rules for chemical modifications of siRNA to enhance the stability and delivery of these molecules for efficient gene silencing in vivo. One of the great potential applications of RNAi-based therapy is to control disease states caused by dominant, gain of function mutations in people bearing one wild-type and one mutant copy of the gene. Some of the best known examples of such diseases are neurodegenerative diseases including Huntingtqn's, a subset of amyotrophic lateral sclerosis (ALS), Alzheimer's and Parkinson's diseases. Although the exact functional pathways delineating how the mutant proteins cause cell degeneration are not entirely clear, the origin of the cellular toxicity is known to be the mutant proteins in these neurodegenerative diseases. We reason that RNAi could be employed to reduce the mutant protein concentrations and thereby slow or block the progression of neurodegenerative diseases. The effectiveness of RNAi in slowing down the ALS progression has been demonstrated in vivo using transgene delivered RNAi. However, the transgene-based delivery has problems in clinical application. In this proposal, we focus on developing siRNA as small molecule drugs. We propose to develop and test chemically modified, stabilized, cell-permeable and silencing competent siRNA in treatment of ALS animal models that express mutant Cu, Zn superoxide dismutase (SOD1). Findings of proposed research will also offer a new perspective important in developing RNAi-based therapies for other neurodegenerative diseases.

Public Health Relevance

RNA interference (RNAi) is a widespread gene-silencing phenomenon with a great potential to therapeutically control disease states caused by dominant, gain of function mutations in people bearing one wild-type and one mutant copy of the gene. Some of the best known examples of such diseases are neurodegenerative diseases including Huntington's, a subset of amyotrophic lateral sclerosis (ALS), Alzheimer's and Parkinson's diseases. The proposed research will determine if RNAi can be used as a new therapeutic approach for ALS.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS060856-02
Application #
7906808
Study Section
Cell Death in Neurodegeneration Study Section (CDIN)
Program Officer
Gubitz, Amelie
Project Start
2009-08-05
Project End
2012-07-31
Budget Start
2010-08-01
Budget End
2012-07-31
Support Year
2
Fiscal Year
2010
Total Cost
$507,034
Indirect Cost
Name
Sanford-Burnham Medical Research Institute
Department
Type
DUNS #
020520466
City
La Jolla
State
CA
Country
United States
Zip Code
92037
Baigude, Huricha; Ahsanullah; Li, Zhonghan et al. (2012) miR-TRAP: a benchtop chemical biology strategy to identify microRNA targets. Angew Chem Int Ed Engl 51:5880-3
Baigude, Huricha; Rana, Tariq M (2012) Interfering nanoparticles for silencing microRNAs. Methods Enzymol 509:339-53
Yang, Chao-Shun; Lopez, Claudia G; Rana, Tariq M (2011) Discovery of nonsteroidal anti-inflammatory drug and anticancer drug enhancing reprogramming and induced pluripotent stem cell generation. Stem Cells 29:1528-36
Su, Jie; Baigude, Huricha; McCarroll, Joshua et al. (2011) Silencing microRNA by interfering nanoparticles in mice. Nucleic Acids Res 39:e38
Ghosh, Animesh; Mukherjee, Koushik; Jiang, Xinpeng et al. (2010) Design and assembly of new nonviral RNAi delivery agents by microwave-assisted quaternization (MAQ) of tertiary amines. Bioconjug Chem 21:1581-7
Baigude, Huricha; Rana, Tariq M (2009) Delivery of therapeutic RNAi by nanovehicles. Chembiochem 10:2449-54