When copper turns killer: Decoding copper dyshomeostasis and cuproptosis in neurodegenerative pathogenesis and precision metal interventions

Copper is an essential cofactor for neuronal metabolism, enzymatic functions, and neurotransmission. However, copper dyshomeostasis-induced redox activity makes the brain vulnerable to oxidative and proteostatic stress. Cuproptosis, a recently characterized form of programmed cell death, is triggered by copper binding to lipoylated enzymes of the tricarboxylic acid cycle, resulting in proteotoxic stress, mitochondrial dysfunction, and cell death. Given that mitochondria are central to copper handling and the primary site of cuproptosis, we examine mitochondrial pathways and key cuproptosis-related genes. We also assess disease-specific signatures of copper imbalance. In Alzheimer's disease, excess copper binds to amyloid-β, promoting aggregation and neurotoxicity. In Parkinson's disease, copper-bound α-synuclein fosters aggregation, while copper-driven redox cycling elevates reactive oxygen species. Cuproptosis worsens mitochondrial vulnerability in Parkinson's disease and impairs cellular stress responses in Huntington's disease. In amyotrophic lateral sclerosis, superoxide dismutase 1-related defects compromise antioxidant defenses alongside copper-dependent mitochondrial dysfunction. In prion diseases, copper facilitates prion protein misfolding and toxicity. Across these disorders, common features include mitochondrial dysfunction and cuproptosis hallmarks-such as enhanced protein lipoylation, elevated reactive oxygen species, impaired electron transport chain activity, fragile Fe-S clusters, and increased reliance on the tricarboxylic acid cycle-which collectively increase neuronal susceptibility to copper dyshomeostasis. Clarifying and understanding the critical roles of copper metabolism not only elucidates the pathogenesis of neurodegenerative diseases but also offers alternative therapeutic strategies. This review uniquely integrates the mitochondria-centered cuproptosis axis with copper dyshomeostasis across Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, and prion diseases, mapping convergent vulnerabilities to mechanism-grounded interventions and outlining testable translational routes.