Clearance Pathways for α-Synuclein in Parkinson's Disease

Protein aggregation and accumulation are hallmark features of neurodegenerative diseases. In Parkinson's disease, the progressive formation and propagation of α-synuclein aggregates-found in Lewy bodies and Lewy neurites-are closely linked to widespread neuronal dysfunction, dopaminergic neuron loss, and the emergence of both motor and nonmotor symptoms, including anosmia, cognitive decline, and depression. Despite their pathological significance, the mechanisms underlying the formation, spread, and clearance of these aggregates remain incompletely understood. In this review, we examine the cellular and molecular pathways responsible for the elimination of protein aggregates in the diseased brain. We first summarize various experimental models of α-synuclein pathology, followed by a discussion of the degradation mechanisms in neurons and glial cells under pathological conditions. These findings offer new insights into cell type-specific clearance pathways and highlight potential therapeutic targets for mitigating α-synuclein-associated toxicity in Parkinson's disease.