Clicked Modified Antisense Oligonucleotides Targeting Hutchinson–Gilford Progeria Syndrome (HGPS)

Hutchinson-Gilford Progeria Syndrome (progeria) is a rare progressive genetic disease which occurs due to a heterozygous single-point mutation in the LAMNA gene. The mutation activates an alternative splice site and consequently, a truncated version of lamin A (progerin) is formed, which produces wobbly lobulated nuclei and rapid cell apoptosis and swollen nuclei.
Earlier, we reported two treating pathways using well-designed ASOs to stop the translation of the progerin via blocking the mRNA, or sterically hindering the spliceosome to bind to the pre-mRNA of the progerin and form the mRNA. Also, it was reported that phenyl-triazole-2´-OMe uridine showed promising results in inducing exon skipping in vitro due to increasing the affinity of the RNA.
Herein we carried out repetitive treatments of progeroid cell cultures with phenyl-triazole uridine modified ASOs which are engineered to prevent the ribosome from translating the progerin's mRNA. Whereas four chemically synthesized monomers were incorporated into ASOs, aiming for higher stability and better binding to the mRNA of the progerin. Phenyl-triazole analogues were attached via click chemistry to the 5-position either of uridine or 2´-OMe-uridine. Six modified ASOs were transfected every other day for ten days in triplicates. Confocal microscopy was used to image the DAPI-stained fixed cells. The change in the nuclear morphology was analysed using Nikon NIS-Elements; 400 to 500 nuclei were analysed per condition. Phenyl triazole-2´-OMe uridine-modified ASO provides an enhancement in the nuclear morphology of the progeroid cells. Where the treated cells show regular cell growth with a similar nuclear area to healthy fibroblasts with the same passage number of cells.
Further biological assays i.e., western blots, PCR, proliferation, and toxicity are still running to analyse the gene expression at protein and RNA levels.