PKM2 alleviates mitochondrial oxidative stress and neuronal apoptosis through metabolic and non-metabolic pathways to protect SOD1G93A mice.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by selective motor neuron death. Dysregulated energy metabolism is implicated in ALS pathogenesis, yet the role of pyruvate kinase M2 (PKM2), a key glycolytic enzyme, remains elusive. Here, we demonstrated that PKM2 expression was upregulated in the spinal neurons of SOD1G93A mice during early stages of disease. Pharmacological inhibition of PKM2 with compound 3k (C3k) shortened survival times, exacerbated motor deficits, and amplified mitochondrial oxidative stress and neuronal apoptosis in mice with ALS. Mechanistically, PKM2 mitigated mitochondrial dysfunction via its enzymatic activity, promoting lactate metabolism to reduce reactive oxygen species (ROS) accumulation. Concurrently, nuclear PKM2 directly bound to the Nrf2 promoter, enhancing Nrf2 transcription to strengthen antioxidant defenses. Our findings unveil PKM2 as a multifunctional neuroprotectant in ALS, offering novel therapeutic directions through metabolic and transcriptional modulation.