Rational design of antisense oligonucleotides targeting single nucleotide polymorphisms for potent and allele selective suppression of mutant Huntingtin in the CNS

Abstract

Autosomal dominant diseases such as Huntington’s disease (HD) are caused by a gain of function mutant protein and/or RNA. An ideal treatment for these diseases is to selectively suppress expression of the mutant allele while preserving expression of the wild-type variant. RNase H active antisense oligonucleotides (ASOs) or small interfering RNAs can achieve allele selective suppression of gene expression by targeting single nucleotide polymorphisms (SNPs) associated with the repeat expansion. ASOs have been previously shown to discriminate single nucleotide changes in targeted RNAs with ∼5-fold selectivity. Based on RNase H enzymology, we enhanced single nucleotide discrimination by positional incorporation of chemical modifications within the oligonucleotide to limit RNase H cleavage of the non-targeted transcript. The resulting oligonucleotides demonstrate >100-fold discrimination for a single nucleotide change at an SNP site in the disease causing huntingtin mRNA, in patient cells and in a completely humanized mouse model of HD. The modified ASOs were also well tolerated after injection into the central nervous system of wild-type animals, suggesting that their tolerability profile is suitable for advancement as potential allele-selective HD therapeutics. Our findings lay the foundation for efficient allele-selective downregulation of gene expression using ASOs—an outcome with broad application to HD and other dominant genetic disorders.

Antisense oligonucleotides in therapy for neurodegenerative disorders

“…Chimeric MOE-PS DNA and cEt antisense oligonucleotides were shown to selectively reduce mutant huntingtin expression in patient-derived cells [158,159]. A single ICV injection of chimeric cEt antisense oligonucleotides in a humanized HD mouse model resulted in reduction in mutant huntingtin expression up to 36 weeks post treatment [87].…”

Synthesis and Properties of 6′-Fluoro-tricyclo-DNA

“…Copies of 1 H-, 13 C-, 19 F-, and 31 P-NMR spectra of compounds 2−18 and X-ray structural data (CIF) of compound 16. This information is available free of charge via the Internet at http://pubs.acs.org…”

Approches degene silencingpour le traitement de la maladie de Huntington

“…De plus, ces molécules sont potentiellement capables de reconnaître les ARNm d'autres gènes contenant des expansions CAG (comme les transcrits de l'ataxine 1 ou de l'atrophine 1), ce qui pourrait induire des effets secondaires. [9,11,32]. L'application de cette même stratégie avec un lentivirus exprimant un shARN ciblant sélectivement la mHTT humaine permet de réduire l'expression de la protéine mutée in vivo de près de 40-70 % dans un modèle animal de la maladie [33].…”