Developing Midbrain-like Organoid of Gaucher Disease as A Platform for Drug Assessment

Gaucher disease (GD) is a lysosomal storage disorder caused by GBA1 mutations, leading to defective acid β-glucosidase (GCase) and accumulation of glucosylsphingolipids, causing inflammation and neurodegeneration. We developed midbrain-like organoids (MLOs) from induced pluripotent stem cells (iPSCs) of nGD patients with GBA1L444P/P415R and GBA1L444P/RecNcil mutations to model nGD brain pathogenesis. These nGD MLOs exhibited GCase deficiencies, reduced enzyme activities, lipids accumulation, transcriptomic alterations, and impaired dopaminergic neuron differentiation, mirroring nGD pathology. GBA1 correction mediated by CRISPR/Cas9 restored GCase activity, normalized lipids levels, and rescued dopaminergic neuron function, confirming the causal role of GBA1 mutations during early brain development. Using this novel platform, we further evaluated therapeutic strategies, including SapC-DOPS nanovesicles delivering GCase, AAV9-GBA1 gene therapy, and substrate reduction therapy (SRT) with GZ452, a glucosylceramide synthase (GCS) inhibitor currently under clinical investigation. These treatments either restored GCase activity, and/or reduced lipid accumulation, improved lysosomal function, and partially corrected dysregulated neural development and lysosomal pathways identified by transcriptomic analysis. These findings highlight MLOs as a physiologically relevant platform for studying nGD mechanisms and testing novel therapies, offering insights into potential treatments for this devastating disorder.