Understanding the Role of VPS35 in the Intracellular Movement of Alpha-Synuclein in Neuronal Cells (360G-Wellcome-211584_Z_18_Z)

Parkinson’s disease (PD) is the second most common neurodegenerative disease after Alzheimer’s disease affecting 10 million people worldwide. A key protein linked to the aetiology of the disorder is alpha-synuclein for which misfolding is linked to the pathogenesis. Importantly alpha-synuclein misfolding can be passed from cell-to-cell by mechanisms which are poorly understood. One proposed mode of transfer is via exosomes, small extracellular vesicles that are released from cells when multi-vesicular endosomes fuse with the plasma membrane. Trafficking in the endosome system therefore has potential to modulate exosome production and affect the transfer of misfolded alpha-synuclein. One gene implicated in late-onset familial PD is vacuolar protein sorting-35 (VPS35). VPS35 is a component of the retromer complex which is a coat protein involved in retrograde trafficking from endosome to the Golgi apparatus. It has the potential to modulate multi-vesicular body (MVB) formation/biogenesis and thereby influence the quantity of exosome-associated alpha-synuclein released from neuronal cells. Our hypothesis is that knockdown of VPS35 will modulate MVB/exosome biogenesis, augmenting the release of exosome-associated alpha-synuclein from cells. We suggest exosomes from VPS35 knockdown cells will be more potent in transfer of alpha-synuclein between cells. This will be observed by using immunoelectron microscopy, Nanocount technology, and immunofluorescence.