Parkinson’s Disease (PD) is a progressive neurodegenerative disorder that affects 1-2% of the population over age 65. Pathologically, PD is marked by a loss of dopaminergic neurons in the substantia nigra pars compacta region of the brain. Because of lack of access to such tissue, or availability of good animal models of PD, iPSC-generated neurons hold promise in the development of model systems to study PD.
We have generated iPSCs from patients harboring mutations in the PARKIN and LRRK2 genes, as well as a rare case with mutations in both the LRRK2 and GBA genes, and a patient with Multiple Systems Atrophy (MSA)--a “Parkinson’s Plus Syndrome” disease with no known genetic determinants. To eliminate line-to-line variations due to genetic background, we also generated a set of isogenic iPSC lines that differ at a single point in the genome using the Transcription Activator-Like (TAL) effector nuclease technology. For instance, we have deleted the a-synuclein gene from the MSA line in order to understand the impact of Lewy bodies, and reverted the LRRK2 and GBA mutations back to wild type in order to better understand any synergies between these mutations. These iPSC lines have been differentiated to neural stem cells (NSCs), and further into dopaminergic neurons and glial cells. Using the NSCs, fluorescence-based, high-throughput compatible assays have been developed to monitor phenotypes that are associated with PD, such as oxidative stress, metabolic activity, apoptosis, mitochondrial function, and autophagy. The hope is that these optimized assays will provide a platform allowing for the facile interrogation of small molecule compounds in “relieving” phenotypes associated with PD.