We hypothesized that alpha-synuclein increased level and accumulation within the target neurons in the affected model acts as a trigger mechanism for activation of additional factors incriminated in Parkinson’s disease (PD) pathogenesis. The specific objectives for this study will be to: (1) Determine by real-time PCR alpha-synuclein mRNA levels in affected and control BD IV pre-clinical model; (2) Identify genetic mutations/or alterations in the alpha-synuclein gene; (3) Determine if alpha-synuclein is secreted and neurotoxic.
Our proposed investigation of alpha-synuclein in the pathogenesis of PD in a pre-clinical model is predicated upon the observation of an unambiguous phenotype, with experimental evidence based on investigative pathology that supports alpha-synuclein as a priority candidate gene. First, we will perform a genome-wide study of genomic rearrangements of autosomal genes in the affected and control rats through array comparative genomic hybridization (aCGH). Second, we will perform microarray sequence capture of candidate genes to identify classical, loss of function mutations. We will investigate if alpha-synuclein is secreted by using the ortotypic brain slice culture. Next we will investigate the possible neurotoxic effect of alpha-synuclein on neurons and glial cells by using primary neural culture. The experiments will clarify if alpha-synuclein accumulates in time in the neurons and glial cells.
Relevance to Diagnosis/Treatment of Parkinson’s Disease:
The development of therapy for PD might evolve from a better understanding of pathogenesis of disease. Our inherited ore-clinical model provides a holistic approach to this disease, which is multifactorial in nature and unique in recapitulating the pathogenesis of human PD. Future in vitro and in vivo studies are needed to identify the factors that control cell-to-cell transfer of alpha-synuclein, and also the impact of genetic alterative changes in the pathogenesis of PD.
Preliminary data require us to engage in a prioritized investigation of de novo mutations in alpha-synuclein within our pre-clinical model. We feel this is a solid first step towards unraveling the causal mutation(s) for our model of PD. Our proposed study is a highly focused investigation that will yield tangible results that either resolve the cause of our PD model in the model, or provide a natural and systematic segue to additional molecular genetic and/or whole-genome approaches.