Start codon disruption with CRISPR/Cas9 prevents murine Fuchs’ endothelial corneal dystrophy

Abstract

A missense mutation of collagen type VIII alpha 2 chain (<i>COL8A2</i>) gene leads to early-onset Fuchs' endothelial corneal dystrophy (FECD), which progressively impairs vision through the loss of corneal endothelial cells. We demonstrate that CRISPR/Cas9-based postnatal gene editing achieves structural and functional rescue in a mouse model of FECD. A single intraocular injection of an adenovirus encoding both the Cas9 gene and guide RNA (Ad-Cas9-Col8a2gRNA) efficiently knocked down mutant <i>COL8A2</i> expression in corneal endothelial cells, prevented endothelial cell loss, and rescued corneal endothelium pumping function in adult <i>Col8a2</i> mutant mice. There were no adverse sequelae on histology or electroretinography. <i>Col8a2</i> start codon disruption represents a non-surgical strategy to prevent vision loss in early-onset FECD. As this demonstrates the ability of Ad-Cas9-gRNA to restore the phenotype in adult post-mitotic cells, this method may be widely applicable to adult-onset diseases, even in tissues affected with disorders of non-reproducing cells.