In Vitro Models for the Evaluation of Antisense Oligonucleotides in Skin.

The genodermatosis dystrophic epidermolysis bullosa (DEB) is caused by mutations in the COL7A1 gene which encodes type VII collagen (C7). In the cutaneous basement membrane zone, C7 secures attachment of the epidermal basal keratinocyte to the papillary dermis by means of anchoring fibril formation. The complete absence of these anchoring fibrils leads to severe blistering of skin and mucosa upon the slightest friction and early mortality. To date, although preclinical advances toward therapy are promising, treatment for the disease is merely symptomatic. Therefore, research into novel therapeutics is warranted.Antisense oligonucleotide (ASO)-mediated exon skipping is such a therapy . Clinical examination of naturally occurring exon skipping suggested that this mechanism could most likely benefit the most severely affected patients. The severe form of DEB is caused by biallelic null mutations. Exon skipping aims to bind an ASO to the mutated exon of the pre-mRNA in the cell nucleus. Thereby, the ASO inhibits the recognition of the mutated exon by the splicing machinery, and as a result, the mutated exon is spliced out from the mRNA with its surrounding introns, i.e., it is skipped. Here, we describe in vitro methods to evaluate ASO-mediated exon skipping in a preclinical setting.