PKM2-driven glycolysis mediates rotenone neurotoxicity via MG-Hs in Parkinson’s disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder lacking disease-modifying therapies. Rotenone (Rot) is widely used to model PD, but its neurotoxicity is not fully understood beyond mitochondrial complex I inhibition. Here, we identify a glycolytic mechanism that contributes to Rot-induced neuronal damage downstream of complex I inhibition. Our in vitro data demonstrate that Rot enhances glycolytic flux, leading to accumulation of methylglyoxal-derived hydroimidazolones (MG-Hs), which drive irreversible cellular damage. Shikonin effectively attenuates Rot-induced apoptosis by inhibiting PKM2, thereby suppressing glycolysis and reducing MG-Hs formation. In a rat model, shikonin robustly improves motor function and preserves nigrostriatal dopaminergic neurons. Collectively, our findings reveal a previously unrecognized glycolytic-mediated pathway involving PKM2-driven glycolysis and MG-Hs accumulation that contributes to rotenone neurotoxicity alongside mitochondrial dysfunction, and highlight shikonin as a promising neuroprotective agent for Parkinson's disease intervention.