?-synuclein impairs autophagosome maturation through abnormal actin stabilization.

ABSTRACT: Vesicular trafficking defects, particularly those in the autophagolysosomal system, have been strongly implicated in the pathogenesis of Parkinson's disease and related ?-synucleinopathies. However, mechanisms mediating dysfunction of membrane trafficking remain incompletely understood. Using a Drosophila model of ?-synuclein neurotoxicity with widespread and robust pathology, we find that human ?-synuclein expression impairs autophagic flux in aging adult neurons. Genetic destabilization of the actin cytoskeleton rescues F-actin accumulation, promotes autophagosome clearance, normalizes the autophagolysosomal system, and rescues neurotoxicity in ?-synuclein transgenic animals through an Arp2/3 dependent mechanism. Similarly, mitophagosomes accumulate in human ?-synuclein-expressing neurons, and reversal of excessive actin stabilization promotes both clearance of these abnormal mitochondria-containing organelles and rescue of mitochondrial dysfunction. These results suggest that Arp2/3 dependent actin cytoskeleton stabilization mediates autophagic and mitophagic dysfunction and implicate failure of autophagosome maturation as a pathological mechanism in Parkinson's disease and related ?-synucleinopathies.

SUBMITTER: Sarkar S 

PROVIDER: S-EPMC7895402 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature