Developing microfluidic devices for cellular modelling of inherited eye diseases

Inherited retinal dystrophies are a leading cause of blindness and visual loss. Over 20,000 individuals in the UK are registered blind or partially sighted because of these conditions, caused by mutations in over 260 genes. However, many genetic variants do not have an ascribed functional significance. Our current inability to interpret the functional consequences of "variants of uncertain significance" limits the value of genetic information for many patients. Understanding the impact of "variants of uncertain significance" allows accurate counselling of patients, improves our knowledge of disease pathogenesis and catalyses the development of novel treatments. Cellular modelling of variants by using microfluidic devices has the potential to hugely increase throughput and capacity of functional assays, but it is an approach that is currently under-studied and under-developed for retinal cells.
Well-established protocols will be used to differentiate induced pluripotent stem cells (iPSCs) into retinal cell types. Variants identified from patients will be genome-edited into iPSCs by using standard CRISPR-Cas9 knock-in methods. Selected knock out retinal iPSCs will be turned into physiological tissue systems on novel "organ-on-a-chip" microfluidic devices, to address the current limitations of genetic variant interpretation. The overall aim of the project is to develop novel and improved methods of in vitro cellular modelling. "Organ-on-a-chip" devices are a clear opportunity to improve throughput and reproducibility through minimizing culture volumes and reducing cell manipulation. This will enable matched sets of functional assays, with a particular focus on using these devices for pre-clinical testing of new therapeutic strategies such as allele-specific knockdown and antisense oligonucleotide therapy.