Huntington’s disease (HD) is a devastating neurodegenerative disease caused by a single mutation, a CAG expansion, in the huntingtin (HTT) gene. The resultant mutant HTT protein has been shown to... Show moreHuntington’s disease (HD) is a devastating neurodegenerative disease caused by a single mutation, a CAG expansion, in the huntingtin (HTT) gene. The resultant mutant HTT protein has been shown to be the predominant toxic entity in the HD pathogenesis and therapeutic strategies that aim to lower the mutant HTT show a great promise. The main objective of this work is to demonstrate a preclinical efficacy of an adeno-associated virus (AAV)-delivery of micro (mi)RNA-based gene therapy for the treatment of HD. We have tested various therapeutic miRNAs to achieve overall HTT protein lowering in HD rodent models and induced pluripotent stem cell (iPSC)-derived HD patient neuronal cultures. Excitingly, we have demonstrated HTT lowering by the AAV5-miHTT in all HD models tested so far with no undesired events, which strongly supported the continuation of preclinical testing in large animals. Furthermore, we provided an evidence suggesting that therapeutic miRNAs can be also active in the nucleus, extending their range of applicability. The possibility to use exosome-enriched vesicles as carriers of pharmacokinetic/pharmacodynamic (PK/PD) measures for the AAV5-miHTT gene therapy, that would signal the presence of the active therapeutic miRNAs in the brain, was further explored in preparation for a first clinical trial in humans. Show less
