The overarching goal of this work is to utilize models of Parkinson’s disease (PD) that originate from cells of PD affected patients harboring mutations within the LRRK2 gene so that we may discern the role of mutated LRRK2 in disease. Mutations in LRRK2 are the most common cause of familial PD. The disease presentation of patients with LRRK2 mutation is typically clinically indistinguishable from sporadic PD cases, making the onset of disease due to LRRK2 dysfunction clinically relevant. We have employed stem cells derived from these patients to generate neuronal cells in which we can determine the roles of LRRK2 in the PD mutated and the unmutated state. We have focused on a cellular process called autophagy that regulates the cell response to nutrient deprivation and plays a role in the selective degradation of proteins within the cell.
In the first year of funding we have analyzed the expression of the protein LRRK2 in induced pluripotent stem cells, neuronal precursor cells and have begun to differentiate the neuronal precursors to dopaminergic cells of the type lost in PD (a difficult task in itself). We have applied a novel method for detection of LRRK2 in situ by marrying the protein detection of antibodies and the sensitivity of nucleic acid amplification. We will continue to develop this methodology for maximum sensitivity to LRRK2. We have established assays to assess the effects of the LRRK2 mutant on autophagy that are relevant to PD and neurological diseases in general. We have met or made great progress on most of our anticipated milestones and are eager to proceed to the next phase of the project.