There is a growing unmet need for a better treatment of Parkinson's disease (PD). Our goal is to improve the understanding of molecular pathways involved in the pathogenesis of this neurodegenerative process, to ultimately find new pharmacological targets for a disease-modifying therapeutic intervention. Identification of Vacuolar protein sorting 35 (VPS35) as the latest autosomal dominant causative gene of PD highlighted the role of retromer and retromer-dependent trafficking in PD. However how exactly VPS35 contributes to PD pathogenesis is entirely unknown, and at present there is no animal model of VPS35 parkinsonism. Therefore the goal of this grant application is to develop the first animal model of VPS35 parkinsonism. Specifically, we are planning to generate a new transgenic Drosophila line that will allow expressing the D647N mutant of Drosophila Vps35 (equivalent to the pathogenic D620N mutation identified in PD patients). We anticipate that expressing Vps35(D647N) in dopaminergic neurons will lead to neuronal death, locomotor deficits, increased sensitivity to rotenone, and impaired autophagy - a cellular process recently implicated in the pathogenesis of several neurodegenerative disorders, including PD. Specifically, we postulate that Vps35 is required for efficient autophagy, and that expressing Vps35(D647N) will impair the autophagic response. In addition, we hypothesize that Vps35(D647N) mutant flies will present with an eye phenotype, similar to many other models of neurodegenerative disorders, including our LRRK2 transgenic fly. Characterization of an eye phenotype would make this animal model valuable in future genetic screens or drug screens. This proposal will provide a new valuable tool to study PD pathogenesis in vivo, one that will help elucidate the mechanisms by which this newly discovered retromer-dependent pathway contributes to PD pathology. This may significantly advance the field of PD and other neurodegenerative disorders, and may uncover new pharmacological targets for a better treatment.
The goal of this proposal is to use a common fruit fly to generate and characterize the first animal model of parkinsonism caused by a specific mutation in a newly discovered Parkinson's disease gene called VPS35. This small but powerful animal model may help us uncover how VPS35 causes Parkinson's disease; what other genes and cellular processes are involved; and what can be done to stop the progression of the disease.