Juvenile neuronal ceroid lipofuscinosis (JNCL or CLN3 disease) is the most common form of NCL disorders, with a global incidence of between 1 and 8 per 100,000 live births. Current approved therapies for CLN3 are limited to symptomatic relief, with no disease-modifying or curative options available. There is a clear need for chronic treatments that can improve both quality and length of life for JNCL patients.
This project aimed to identify compounds with potential disease-modifying effects, which may also hold therapeutic relevance for other lysosomal, neurodegenerative or epileptic disorders.
The broad project aims were to document and characterise CLN3 disease cell phenotypes across multiple cell lines via fluorescent microscopy techniques to enhance our understanding of the intracellular mechanisms of disease. The later aims were to develop a phenotypic assay for high-content screening.
Disease characterisation and optimisation of the phenotypic drug screen have been completed with measurements from the major cell components such as the endolysosomal system, mitochondrial networks, and intracellular storage of macromolecules. This in-depth characterisation enabled the development and optimisation of a phenotypic assay suitable for high-content drug screening.
By utilising lysosomal swelling as a measurable and disease relevant phenotype, a high-content phenotypic drug screen of over 4000 small molecules was conducted at a specialist facility at Simon Fraser University, Canada. Owing to the broad nature of the phenotype, the assay may also be applicable to other forms of NCL and lysosomal storage disorders.
The screen identified phenotype enhancers and suppressors, with 24 phenotype suppressing compounds selected for further secondary testing. One notable finding raises important questions about the potential impact of certain anti-epileptic drugs in the context of CLN3 disease
Overall, this work establishes a robust platform for phenotypic drug discovery in CLN3 disease and contributes to broader efforts in therapeutic repurposing for lysosomal disorders.