von Willebrand Factor fibers formed at pathological high shear provide a scaffold for α-synuclein binding and aggregation.

α-Synuclein (αSyn) is an intrinsically disordered protein whose misfolding and aggregation promotes various synucleinopathies. Potentially relevant to the biophysics of αSyn-dependent pathology as well as seed amplification assays, we tested fibrous von Willebrand factor (vWF-fibers) generated at high shear for its ability to capture αSyn and induce αSyn misfolding. EDTA-plasma was perfused through a post-impingement microfluidic device at a peak shear rate of ~ 20,000 s−1 to generate vWF-fibers. Monomeric αSyn was then perfused over the vWF-fibers. In other experiments, pre-formed αSyn aggregates were perfused over vWF-fibers. X-34, a β-sheet-specific fluorescent dye, was used to label β-sheet structures, including vWF. Alexafluor-488-conjugated MJFR-14-6-4-2, an alpha-synuclein aggregate antibody, was used to label aggregated αSyn. The microposts effectively generated vWF-fibers. When monomeric α-Syn was perfused over vWF fibers, MJFR-14-6-4-2 revealed strong fluorescence staining relative to buffer control. Pre-formed aggregates also bound vWF-fibers. Annexin V and CD63 staining indicated the presence of plasma-derived phosphatidylserine-positive puncta on vWF-fibers. FITC-conjugated α-Syn monomer localized significantly on the vWF-fibers. Pathological vWF-fibers and bound PS-positive vesicles act as a scaffold on which αSyn can bind, misfold and aggregate. Additionally, vWF-fibers can bind/entrap preformed aggregates of αSyn. This study suggests potential crosstalk between vWF hemorheology and synuclein localization.