Electroacupuncture Downregulating Neuronal Ferroptosis in MCAO/R Rats by Activating Nrf2/SLC7A11/GPX4 Axis

Abstract

AbstractIschemic stroke involves various pathological processes, among which ferroptosis is crucial. Previous studies by our group have indicated that electroacupuncture (EA) mitigates ferroptosis after ischemic stroke; however, the precise mechanism underlying this effect remains unclear. In the present study, we developed a rat model of middle cerebral artery occlusion/reperfusion. We chose the main acupoint of the treatment methods of the “Awakening and Opening of the Brain”. Rats’ neurological function and motor coordination were evaluated by neurological function score and the rotarod test, respectively, and the volume of cerebral infarction was analyzed by 2,3,5-triphenyltetrazolium chloride Staining. The cerebrovascular conditions were visualized by time-of-flight magentic resonance angiography. In addition, we detected changes in lipid peroxidation and endogenous antioxidant activity by measuring the malondialdehyde, glutathione, superoxide dismutase activities, glutathione/oxidized glutathione and reduced nicotinamide adenine dinucleotide phosphate/oxidized nicotinamide adenine dinucleotide phosphate ratios. Inductively coupled plasma-mass spectrometry, western blot, reverse transcription-polymerase chain reaction, fluoro-jade B staining, immunofluorescence analysis, and transmission electron microscopy were utilized to examine the influence of EA. The results indicate that EA treatment was effective in reversing neurological impairment, neuronal damage, and protecting mitochondrial morphology and decreasing the cerebral infarct volume in the middle cerebral artery occlusion/reperfusion rat model. EA reduced iron levels, inhibited lipid peroxidation, increased endogenous antioxidant activity, modulated the expression of several ferroptosis-related proteins, and promoted nuclear factor-E2-related factor 2 (Nrf2) nuclear translocation. However, the protective effect of EA was hindered by the Nrf2 inhibitor ML385. These findings suggest that EA can suppress ferroptosis and decrease damage caused by cerebral ischemia/reperfusion by activating Nrf2 and increasing the protein expression of solute carrier family 7 member 11 and glutathione peroxidase 4.