Duplex RNAs and ss-siRNAs Block RNA Foci Associated with Fuchs’ Corneal Endothelial Dystrophy

Abstract

Purpose : Fuchs’ Endothelial Corneal Dystrophy (FECD) leads to vision loss and is one of the most common inherited ocular diseases. Corneal transplants are the only curative treatment available and there is a major unmet need for treatments that are less invasive and independent of donor tissue. Most cases of FECD are associated with an expanded CUG repeat within the intronic region of TCF4 and the mutant RNA has been implicated as the cause of the disease. We previously reported preliminary data suggesting that single-stranded antisense oligonucleotides (ASOs) can inhibit CUG RNA foci in patient derived cells and tissue. In this project, we test the hypotheses that duplex RNAs, ss-siRNAs, and chemically modified ASOs can block CUG RNA foci in patient-derived cells.

Methods : Duplex RNAs were purchased from IDT (Newark, NJ). ss-siRNAs and ASOs were synthesized at Ionis Pharmaceutics (Carlsbad, CA) and reconstituted in nuclease-free water. Duplex RNAs or ss-siRNAs were transfected into patient-derived cells with lipid RNAiMAX (Life Technologies) as previously described. Cells were plated at a density of 300K per well of a 6-well plate and transfection was performed at the same time. Cells were typically harvested 4 days after transfection for RNA FISH assay.

Results : We now demonstrate that the RNAi mechanism can also be exploited to design active compounds. Both duplex RNAs and single-stranded silencing RNAs (ss-siRNAs) reduce the number of cells with foci and the number of foci per cells. Potencies are similar those that achieved with chemically modified antisense oligonucleotides designed to block foci.

Conclusions : These data widen the potential for synthetic nucleic acids to be used to treat a widely prevalent and debilitating disease of FECD.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.