Lihan Xu

Focused Biomedical Scientist demonstrating a specialty in iPSC-derived cell model. Always curious, seeking new challenges and collaborations to create a better place for patients through science.

High throughput screening assay for dominant BEST1 mutations to identify therapeutic compounds in an iPSC-RPE platform

Evotec is a biotech company with extensive expertise in cell therapy, drug screening and therapy development. In this program, the PhD student (DC3) will differentiate patient or CRISPR-Cas9 derived iPSCs, carrying an autosomal dominant BEST1 mutation, into RPE cells using our unique in-house protocol. BEST1 mutant iPSC-RPE will be characterized for mislocalized BEST1, accumulation of lipofuscin and reduced calcium flux, and compared to wild type control iPSC-RPE. In addition, BEST1 mutant and control iPSC-RPE will be analyzed on transcriptome level with and without photoreceptor outer segment addition, to elucidate disease-relevant cellular pathways. Next, DC3 will establish a high-throughput compatible screening assay, which enables a proof of concept (POC) screening campaign with small, bio-annotated molecules to revert the observed cellular phenotypes. Evotec has access to a large screening library of over 450,000 compounds and a subset of this library of approximately 1,000-2,000 compounds will be used. The development of high-throughput screening assay in an industry setting is essential to develop meaningful therapies for patients, since the quality requirements for such an assay are very high and require, at least partially, automation steps. Depending on the mechanisms, DC3 will evaluate other treatment modalities such as antisense oligonucleotides (AONs), in collaboration with DC7 and DC8. We anticipate that correcting mutant BEST1 phenotypes, such as protein mislocalization, will restore cellular RPE function. Potential therapeutic compounds, identified through the POC screen, will be confirmed in the primary and secondary screening assays, as well as in complex 3D models, such as a co-culture of retinal organoid (ROs) and RPE cells. Any compounds identified in the POC screen will also be tested in this complex model and will therefore enhance the translatability of in vitro findings into the clinic.