SNCA triplication disrupts proteostasis and extracellular architecture prior to neurodegeneration in human midbrain organoids

ABSTRACT: Synucleinopathies, including Parkinson’s disease, are characterized by α-synuclein aggregation and progressive neurodegeneration, yet the early molecular events linking SNCA gene dosage to disrupted proteostasis remain poorly understood. Here, we used human midbrain organoids carrying an SNCA triplication (SNCA Trip) and the isogenic corrected line (SNCA Isog) to dissect early pathogenic mechanisms in a 3D human model of synucleinopathy. We combined immunohistochemistry, immunoblotting, tandem mass tag proteomics, bulk RNA sequencing, and ribosome profiling to systematically characterize molecular alterations in SNCA Trip organoids at day 50 (D50) and day 100 (D100) of maturation. SNCA Trip organoids exhibited increased α-synuclein accumulation, neuromelanin deposition, and activation of mTORC1 (p-rpS6), ERK1/2, and p-eIF2α signalling pathways by D100. Proteomic and transcriptomic analyses revealed upregulation of cytoskeletal, synaptic, and axonal development pathways, alongside significant downregulation of extracellular matrix (ECM) components. Ribosome profiling showed minimal global translational changes but uncovered selective translational buffering of neuronal and ECM-associated transcripts. Confocal imaging confirmed progressive disorganization of pericellular and interstitial ECM structures around neurons in SNCA Trip organoids. Our findings demonstrate that SNCA triplication induces early proteostatic disruption and extracellular matrix remodelling prior to neurodegeneration, suggesting that altered translation and ECM homeostasis may contribute to disease initiation and progression. Targeting these early aberrant mechanisms may offer new therapeutic opportunities for synucleinopathies, such as Parkinson’s Disease.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Pluripotent Stem Cell, Cell Culture

DISEASE(S): Parkinson's Disease 1

SUBMITTER: Frank Stein  

LAB HEAD: Christos G. Gkogkas

PROVIDER: PXD063729 | Pride | 2026-04-06

REPOSITORIES: Pride