Patient-derived three-dimensional cortical neurospheres to model Parkinson's disease

There are currently no preventive or disease-modifying therapies for Parkinson's Disease (PD). Failures in clinical trials necessitate a re-evaluation of existing pre-clinical models in order to adopt systems that better recapitulate underlying disease mechanisms and better predict clinical outcomes. In recent years, models utilizing patient-derived induced pluripotent stem cells (iPSC) have emerged as attractive models to recapitulate disease-relevant neuropathology in vitro without exogenous overexpression of disease-related pathologic proteins. Here, we utilized iPSC derived from patients with early-onset PD and dementia phenotypes that harbored either a point mutation (A53T) or multiplication at the alpha-synuclein/SNCA gene locus. We generated a three-dimensional (3D) cortical neurosphere culture model to better mimic the tissue microenvironment of the brain. We extensively characterized the differentiation process using quantitative PCR, Western immunoblotting and immunofluorescence staining. Differentiated and aged neurospheres revealed alterations in fatty acid profiles and elevated total and pathogenic phospho-alpha-synuclein levels in both A53T and the triplication lines compared to their isogenic control lines. Furthermore, treatment of the neurospheres with a small molecule inhibitor of stearoyl CoA desaturase (SCD) attenuated the protein accumulation and aberrant fatty acid profile phenotypes. Our findings suggest that the 3D cortical neurosphere model is a useful tool to interrogate targets for PD and amenable to test small molecule therapeutics.

Automated summary

Currently, there is no preventive or disease-modifying therapy available for Parkinson's Disease (PD). The failure of clinical trials calls for a re-evaluation of pre-clinical models that better replicate disease mechanisms and predict clinical outcomes. Patient-derived induced pluripotent stem cell (iPSC) models have recently emerged as attractive options to mimic disease-relevant neuropathology in vitro without artificially overexpressing disease-related proteins. In this study, iPSCs derived from early-onset PD patients with specific mutations were utilized to generate a three-dimensional cortical neurosphere model. The model showed alterations in fatty acid profiles and increased levels of pathogenic proteins, which could be attenuated by a small molecule inhibitor. These findings suggest that the 3D cortical neurosphere model is a useful tool for investigating PD and testing potential therapeutics.