Inhibition of alpha synuclein aggregation by multifunctional dopamine agonists assessed by a novel in vitro assay and an in vivo Drosophila synucleinopathy model
Aggregation of alpha synuclein (a syn) leading to dopaminergic neuronal death has been recognized as one of the main pathogenic factors in the initiation and progression of Parkinson's disease (PD) Consequently, a syn has been targeted for the development of therapeutics for PD. We have developed a novel assay to screen compounds with a syn modulating properties by mimicking recent findings from in vivo animal studies involving intrastriatal administration of pre formed fibrils in mice, resulting in increased a syn pathology accompanying the formation of Lewy body (LB) type inclusions. We found that in vitro generated a syn pre formed fibrils induce seeding of a syn monomers to produce aggregates in a dose and time dependent manner under static conditions in vitro. These aggregates were toxic towards rat pheochromocytoma cells (PC12) Our novel multifunctional dopamine agonists D 519 and D 520 exhibited significant neuroprotection in this assay, while their parent molecules did not. The neuroprotective properties of our compounds were further evaluated in a Drosophila model of synucleinopathy. Both of our compounds showed protective properties in fly eyes against the toxicity caused by a syn. Thus, our in vitro results on modulation of aggregation and toxicity of a syn by our novel assay were further validated with the in vivo experiments.
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