MiR-298 Counteracts Mutant Androgen Receptor Toxicity in Spinal and Bulbar Muscular Atrophy

Authors

• N Pourshafie
• P Lee
• K Chen
• G Harmison
• L Bott
• M Katsuno
• G Sobue
• B Burnett
• K Fischbeck
• C Rinaldi

Abstract

Spinal and bulbar muscular atrophy (SBMA) is a currently untreatable adult-onset neuromuscular disease caused by expansion of a polyglutamine repeat in the androgen receptor (AR). In SBMA, as in other polyglutamine diseases, a toxic gain of function in the mutant protein is an important factor in the disease mechanism; therefore, reducing the mutant protein holds promise as an effective treatment strategy. In this work we evaluated a microRNA (miRNA) to reduce AR expression. From a list of predicted miRNAs that target human AR, we selected microRNA-298 (miR-298) for its ability to down-regulate AR mRNA and protein levels when transfected in cells overexpressing wild-type and mutant AR and in SBMA patient-derived fibroblasts. We showed that miR-298 directly binds to the 3'-untranslated region (UTR) of the human AR transcript, and counteracts AR toxicity in vitro. Intravenous delivery of miR- 298 with adeno-associated virus serotype 9 vector resulted in efficient transduction of muscle and spinal cord and amelioration of the disease phenotype in SBMA mice. Our findings support the development of miRNAs as a therapeutic strategy for SBMA and other neurodegenerative disorders caused by toxic proteins.

Scientific Focus Area: Neuroscience

This page was last updated on Friday, March 26, 2021