Splicing Modulation via Antisense Oligonucleotides in Recessive Dystrophic Epidermolysis Bullosa

oleh: Stefan Hainzl, Lisa Trattner, Bernadette Liemberger, Johannes Bischof, Thomas Kocher, Michael Ablinger, Alexander Nyström, Astrid Obermayer, Alfred Klausegger, Christina Guttmann-Gruber, Verena Wally, Johann W. Bauer, Josefina Piñón Hofbauer, Ulrich Koller

Format: Article
Diterbitkan: MDPI AG 2024-01-01

Deskripsi

Antisense oligonucleotides (ASOs) represent an emerging therapeutic platform for targeting genetic diseases by influencing various aspects of (pre-)mRNA biology, such as splicing, stability, and translation. In this study, we investigated the potential of modulating the splicing pattern in recessive dystrophic epidermolysis bullosa (RDEB) patient cells carrying a frequent genomic variant (c.425A > G) that disrupts splicing in the <i>COL7A1</i> gene by using short 2′-O-(2-Methoxyethyl) oligoribo-nucleotides (2′-MOE ASOs). <i>COL7A1</i>-encoded type VII collagen (C7) forms the anchoring fibrils within the skin that are essential for the attachment of the epidermis to the underlying dermis. As such, gene variants of <i>COL7A1</i> leading to functionally impaired or absent C7 manifest in the form of extensive blistering and wounding. The severity of the disease pattern warrants the development of novel therapies for patients. The c.425A > G variant at the <i>COL7A1</i> exon 3/intron 3 junction lowers the efficiency of splicing at this junction, resulting in non-functional C7 transcripts. However, we found that correct splicing still occurs, albeit at a very low level, highlighting an opportunity for intervention by modulating the splicing reaction. We therefore screened 2′-MOE ASOs that bind along the <i>COL7A1</i> target region ranging from exon 3 to the intron 3/exon 4 junction for their ability to modulate splicing. We identified ASOs capable of increasing the relative levels of correctly spliced <i>COL7A1</i> transcripts by RT-PCR, sqRT-PCR, and ddPCR. Furthermore, RDEB-derived skin equivalents treated with one of the most promising ASOs exhibited an increase in full-length C7 expression and its accurate deposition along the basement membrane zone (BMZ).