Investigating the role of RNA interference in retinal development and as an agent of degeneration (360G-Wellcome-109053_Z_15_A)

Genetic diseases affecting the retina, are the leading cause of blindness in the developed world. Despite the wide knowledge of the genetic factors which result in retinal dystrophies, (more than 200 genes have been identified as playing a role) such conditions remain untreatable. In monogenic retinal dystrophies the age of onset of photoreceptor cell death and rate of sight loss varies, yet the pathogenic gene mutation is present throughout life. Why some cells die at a given point in time and others do not, is unknown. This project aims to investigate the role of endogenous micro RNAs (miRNA) in retinal development and the relationship between miRNA dysregulation and retinal dystrophy. Specific miRNAs will be inactivated using the CRISPR/Cas9 system and the effects on photoreceptor differentiation and optic cup lamination determined. Furthermore, retinal organoid cultures derived from Type I Usher (a syndromic retinopathy) patient induced-pluripotent stem cells (iPSC; derived by reprogramming skin fibroblasts), will be used to establish whether miRNA dysregulation is indicative of an early disease state and whether CRISPR/Cas9-based gene correction can return dysregulated miRNA levels to normal. Finally, the effects of delivering certain miRNAs to a mouse model of retinal dystrophy on early disease phenotype will be established.