Synthetic Nucleic Acids and Treatment of Neurological Diseases

David R. Corey, PhD; JAMA Neurol. 2016;73(10):1238-1242. doi:10.1001/jamaneurol.2016.2089

Emerging Target: Frataxin/Friedreich’s Ataxia: We reasoned that oligonucleotides that blocked the expanded repeat could prevent R-loop formation and release the break on transcription We designed duplex RNAs or ASOs to be complementary to the AAG repeat. Both approaches led to increased expression of RNA and protein. Levels of FXN protein were similar to those observed in wild-type cells. Our data suggest that the mechanism of action of either the ASOs or the duplex RNAs involves binding to the expanded repeat and physically preventing it from associating chromosomal DNA to form the critical R-loop structure. Antisense oligonucleotides efficiently inhibit gene expression in liver and the central nervous system.Using them to treat the broad range of tissues necessary to fully treat Friedreich’s ataxia will require more potent compounds and more effective strategies for delivering oligonucleotides in to all tissues that are affected.