npj Parkinson's Disease (Nov 2023)

USP19 deubiquitinase inactivation regulates α-synuclein ubiquitination and inhibits accumulation of Lewy body-like aggregates in mice

  • Lenka Schorova,
  • Nathalie Bedard,
  • Anouar Khayachi,
  • Hung-Hsiang Ho,
  • Joao Bolivar-Pedroso,
  • Julie Huynh,
  • Mikaela Piccirelli,
  • Yifei Wang,
  • Marie Plourde,
  • Wen Luo,
  • Esther del Cid-Pellitero,
  • Irina Shlaifer,
  • María José Castellanos-Montiel,
  • Ziqi Yu,
  • Dulce Valeria Carrillo Valenzuela,
  • María Lacalle-Aurioles,
  • Anita Kriz,
  • Yihong Ye,
  • Thomas M. Durcan,
  • Simon S. Wing

DOI
https://doi.org/10.1038/s41531-023-00601-1
Journal volume & issue
Vol. 9, no. 1
pp. 1 – 16

Abstract

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Abstract The USP19 deubiquitinase is found in a locus associated with Parkinson’s Disease (PD), interacts with chaperonins, and promotes secretion of α-synuclein (α-syn) through the misfolding-associated protein secretion (MAPS) pathway. Since these processes might modulate the processing of α-syn aggregates in PD, we inactivated USP19 (KO) in mice expressing the A53T mutation of α-syn and in whom α-syn preformed fibrils (PFF) had been injected in the striatum. Compared to WT, KO brains showed decreased accumulation of phospho-synuclein (pSyn) positive aggregates. This improvement was associated with less activation of microglia and improved performance in a tail-suspension test. Exposure of primary neurons from WT and KO mice to PFF in vitro also led to decreased accumulation of pSyn aggregates. KO did not affect uptake of PFF nor propagation of aggregates in the cultured neurons. We conclude that USP19 instead modulates intracellular dynamics of aggregates. At an early time following PFF injection when the number of pSyn-positive neurons were similar in WT and KO brains, the KO neurons contained less aggregates. KO brain aggregates stained more intensely with anti-ubiquitin antibodies. Immunoprecipitation of soluble proteins from WT and KO brains with antibodies to pSyn showed higher levels of ubiquitinated oligomeric species in the KO samples. We propose that the improved pathology in USP19 KO brains may arise from decreased formation or enhanced clearance of the more ubiquitinated aggregates and/or enhanced disassembly towards more soluble oligomeric species. USP19 inhibition may represent a novel therapeutic approach that targets the intracellular dynamics of α-syn complexes.