ADP-ribose triggers neuronal ferroptosis by rewiring purine and pyrimidine metabolism

Abstract

Hyperactivation of NAD+-consuming pathways frequently occurs in neurological diseases, however therapies replenishing NAD+ levels show limited therapeutic efficacy, indicating more complex underlying pathophysiology. Here, we delineate a pathogenic link between ADP-ribose --a product of NAD+ consumption--and a metabolic rewiring-dependent form of neuronal ferroptosis. We demonstrate that oxidative stress induces neurons to produce ADP-ribose through the PARP1-PARG axis. ADP-ribose directly binds and inhibits the equilibrative nucleoside transporter ENT2, remodeling de novo purine and pyrimidine synthesis by hyperactivating the inosine-hypoxanthine-xanthine oxidase and glutamine-dihydroorotate-dihydroorotate dehydrogenase axes. This overproduces superoxide radicals and drives lipid peroxidation and neuronal ferroptosis. Elevated ADP-ribose levels were observed in neurological disease models, and acute ADP-ribose exposure severely reduced mouse brain neurons in vivo. Critically, interventions blocking ADP-ribose signaling alleviated cognitive decline in mouse intracerebral hemorrhage models. Our findings characterize ADP-ribose signaling as linking NAD+ consumption to neuronal ferroptosis, and provide a theraputic strategy for neuropathologies involving NAD+ consumption and oxidative stress.