Objective/Rationale:
Mutations in the LRRK2 gene are a common cause of familial Parkinson’s disease. Familial LRRK2 mutations induce neuronal toxicity in vitro. Reliable pre-clinical models of LRRK2-induced neurodegeneration do not currently exist. However, we have successfully developed a model of G2019S LRRK2-induced dopaminergic neurodegeneration by adenoviral-mediated gene transfer. This project aims to characterize and optimize new helper-dependent human adenoviral serotype 5 (Hd-Ad5) vectors for expressing human LRRK2 in vivo in the nigrostriatal pathway.
Project Description:
The MJFF have recently developed Hd-Ad5 vectors for expressing full-length human LRRK2 variants or GFP in the nigrostriatal pathway of pre-clinical models by viral-mediated gene transfer. Here, we will characterize these new Hd-Ad5 vectors for use in vivo by demonstrating high-level and equivalent expression of LRRK2 variants following intrastriatal delivery. We will establish the optimal dose of virus for efficient transduction of the striatum and retrograde transport to substantia nigra dopaminergic neurons. Hd-Ad5 vectors will then be used to confirm the pathogenic effects of the familial G2019S LRRK2 by inducing progressive dopaminergic degeneration relative to wild-type LRRK2 and GFP expression. Furthermore, the contribution of kinase activity to this process will be determined by using a kinase-dead version of G2019S LRRK2. Our studies aim to establish Hd-Ad5-mediated LRRK2 delivery as a robust pre-clinical model of Parkinson’s disease, and the contribution of kinase activity to LRRK2-dependent neurdegeneration.
Relevance to Diagnosis/Treatment of Parkinson’s Disease:
These studies will develop a pre-clinical model of Parkinson’s disease (PD) with dopaminergic neurodegeneration based upon the expression of the most common disease-associated LRRK2 mutation, G2019S. This model will help to understand the underlying mechanism of neurodegeneration induced by LRRK2 familial mutations and may provide a valuable pre-clinical model for evaluation of LRRK2-based therapeutics for treating PD.
Anticipated Outcome:
This project will evaluate the progressive dopaminergic neurodegeneration induced by the Hd-Ad5-mediated expression of G2019S LRRK2 in a pre-clinical brain and the contribution of kinase activity to the pathological effects of mutant LRRK2. These studies will guide the development of future therapies based upon modulating LRRK2 activity.