Formation of seeding-competent α-synuclein aggregates in parkin-deficient iPSC-derived human neurons

Abstract Loss-of-function mutations in PARK2 (parkin) cause early-onset familial Parkinson’s disease (PD) and may also contribute to sporadic PD. While Lewy bodies, enriched in aggregated phosphorylated α-synuclein (α-Syn), are typical in PD, their presence in PARK2-mediated PD remains debated. Usin...

Full description

Saved in:
Bibliographic Details
Main Authors: Sissel Ida Schmidt, Justyna Okarmus, Daniel Aghaie Madsen, Julie Schmidt Hansen, Emil Gregersen, Hjalte Gram, Lucas S. Winkelmann, Anderson Souza Oliveira, Rachel Heon-Roberts, Brent J. Ryan, Kristine Freude, Morten Blaabjerg, Poul Henning Jensen, Morten Meyer
Format: Article
Language:English
Published: Nature Portfolio 2025-06-01
Series:npj Parkinson's Disease
Online Access:https://doi.org/10.1038/s41531-025-01038-4
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract Loss-of-function mutations in PARK2 (parkin) cause early-onset familial Parkinson’s disease (PD) and may also contribute to sporadic PD. While Lewy bodies, enriched in aggregated phosphorylated α-synuclein (α-Syn), are typical in PD, their presence in PARK2-mediated PD remains debated. Using human isogenic PARK2 −/− induced pluripotent stem cell-derived neurons, we investigated α-Syn pathology under parkin deficiency. PARK2 −/− neurons showed elevated intracellular aggregated and total α-Syn levels, increased α-Syn release, and higher levels of aggregation-inducing α-Syn seeds. These neurons also displayed more pSer129 α-Syn+ inclusions, which were further enhanced by α-Syn preformed fibril (PFF) exposure. Moreover, we identified synaptic loss in the PARK2 −/− neurons, exacerbated by PFF treatment, and dysregulated Ca2+ homeostasis consistent with enhanced activity of the smooth endoplasmic reticulum Ca2+-ATPase (SERCA). Our data provide an important contribution to the debate on the role of α-Syn in the pathology of PARK2-related PD and challenge the view of PARK2-related PD as a non-synucleinopathy.
ISSN:2373-8057