Cathodal Transcranial Direct Current Stimulation Attenuates Cerebral Ischemia-Reperfusion Injury by Coordinating Mitophagy Inhibition and Nrf2 Activation Against Ferroptosis

Aims: Cathodal transcranial direct current stimulation (C-tDCS), a noninvasive physical therapy, has potential neuroprotective effects in acute ischemic stroke. However, the rational timing of its application and the underlying mechanisms remain inadequately understood. This study aims to investigate its neuroprotective effects and the involved mechanisms. Results: Our in vivo results indicated that C-tDCS applied during the reperfusion phase but not during the ischemic phase significantly improved neurological outcomes, reduced infarct volume, and mitigated histopathological damage in middle cerebral artery occlusion/reperfusion rats. C-tDCS during the reperfusion phase suppressed ferroptosis, activated nuclear factor erythroid 2-related factor 2 (Nrf2), and inhibited mitophagy. In vitro, the ferroptosis inducer RSL3 negated the protective effects of cathodal direct current stimulation on HT22 neuronal cells subjected to oxygen-glucose deprivation/reoxygenation injury. Furthermore, the Nrf2 inhibitor ML385 and the mitophagy activator FCCP reversed the inhibitory effects of C-tDCS on ferroptosis, with FCCP also affecting Nrf2 activation by C-tDCS. Innovation and Conclusions: These results demonstrate that C-tDCS during reperfusion attenuates cerebral ischemia-reperfusion injury by coordinating mitophagy inhibition and Nrf2 activation to counteract ferroptosis, which provides new evidence for its potential translational clinical applications. Antioxid. Redox Signal. 00, 000-000.