Allele-specific silencing as treatment for gene duplication disorders: Proof-of-principle in autosomal dominant leukodystrophy

Elisa Giorgio, Martina Lorenzati, Pia Rivetti Di Val Cervo, Alessandro Brussino, Manuel Cernigoj, Edoardo Della Sala, Anna Bartoletti Stella, Marta Ferrero, Massimiliano Caiazzo, Sabina Capellari, Pietro Cortelli, Luciano Conti, Elena Cattaneo, Annalisa Buffo, Alfredo Brusco

Research output: Contribution to journalArticlepeer-review

Abstract

Allele-specific silencing by RNA interference (ASP-siRNA) holds promise as a therapeutic strategy for downregulating a single mutant allele with minimal suppression of the corresponding wild-type allele. This approach has been effectively used to target autosomal dominant mutations and single nucleotide polymorphisms linked with aberrantly expanded trinucleotide repeats. Here, we propose ASP-siRNA as a preferable choice to target duplicated disease genes, avoiding potentially harmful excessive downregulation. As a proof-of-concept, we studied autosomal dominant adult-onset demyelinating leukodystrophy (ADLD) due to lamin B1 (LMNB1) duplication, a hereditary, progressive and fatal disorder affecting myelin in the CNS. Using a reporter system, we screened the most efficient ASP-siRNAs preferentially targeting one of the alleles at rs1051644 (average minor allele frequency: 0.45) located in the 30 untranslated region of the gene. We identified four siRNAs with a high efficacy and allele-specificity, which were tested in ADLD patient-derived fibroblasts. Three of the small interfering RNAs were highly selective for the target allele and restored both LMNB1 mRNA and protein levels close to control levels. Furthermore, small interfering RNA treatment abrogates the ADLD-specific phenotypes in fibroblasts and in two disease-relevant cellular models: Murine oligodendrocytes overexpressing human LMNB1, and neurons directly reprogrammed from patients' fibroblasts. In conclusion, we demonstrated that ASP-silencing by RNA interference is a suitable and promising therapeutic option for ADLD. Moreover, our results have a broad translational value extending to several pathological conditions linked to gene-gain in copy number variations.

Original languageEnglish
Pages (from-to)1905-1920
Number of pages16
JournalBrain
Volume142
Issue number7
DOIs
Publication statusPublished - Jul 2019

Keywords

  • ADLD
  • leukodystrophy
  • LMNB1
  • RNA therapeutics
  • siRNA

ASJC Scopus subject areas

  • Clinical Neurology

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