Objective:To evaluate the relationship between superoxide dismutase 2 (SOD2) lactylation and nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy-ferroptosis during cerebral ischemia-reperfusion (IR) in mice.Methods:Thirty-six clean-grade male C57BL/6 mice, aged 8-10 weeks, weighing 22-25 g, were divided into 4 groups ( n=9 each) using a table of random numbers: sham operation group (Sham group), cerebral IR group (IR group), IR+ glycolysis inhibitor 2-DG group (IR+ 2-DG group), and IR+ 2-DG+ NCOA4 overexpression group (IR+ 2-DG+ LvNCOA4 group). The model of cerebral IR injury was established by occlusion of the middle cerebral artery for 1 h followed by 24 h of reperfusion using the intraluminal suture method in anesthetized animals. 2-DG 250 mg/kg was intraperitoneally injected at 90 min before ischemia in IR+ 2-DG and IR+ 2-DG+ LvNCOA4 groups. The lentivirus overexpressing NCOA4 2 μl was injected into the ventricles at 7 days before ischemia in IR+ 2-DG+ LvNCOA4 group. The percentage of cerebral infarct volume was determined, the viable neurons were counted, and the levels of reactive oxygen species (ROS), malondialdehyde (MDA), and glutathione (GSH) were measured by enzyme-linked immunosorbent assay. The expression of SOD2, lysine 114 lactylation of superoxide dismutase 2 (SOD2-K114la), NCOA4, microtubule-associated protein 1 light chain 3β (LC3B), and acyl-CoA synthetase long-chain family member 4 (ACSL4) was determined by Western blot. Mitochondrial morphology was examined by electron microscopy. Results:Compared with Sham group, the percentage of cerebral infarct volume was significantly increased, the number of viable neurons was decreased, the levels of ROS and MDA were elevated, the content of GSH was reduced, the expression of SOD2-K114la, NCOA4, LC3B and ACSL4 was up-regulated, the expression of SOD2 was down-regulated ( P<0.05), and the mitochondrial injury was aggravated in IR group. Compared with IR group, the percentage of cerebral infarct volume was significantly decreased, the number of viable neurons was increased, the mitochondrial injury was alleviated, the levels of ROS and MDA were decreased, the content of GSH was increased, the expression of SOD2-K114la, NCOA4 and ACSL4 was down-regulated, and the expression of SOD2 and LC3B was up-regulated in IR+ 2-DG group ( P<0.05). Compared with IR+ 2-DG group, the percentage of cerebral infarct volume was significantly increased, the number of viable neurons was decreased, the levels of ROS and MDA were elevated, the content of GSH was reduced, and the expression of NCOA4, LC3B and ACSL4 was up-regulated ( P<0.05), no significant change was found in the expression of SOD2 and SOD2-K114la ( P>0.05), and the mitochondrial injury was aggravated in IR+ 2-DG+ LvNCOA4 group. Conclusions:SOD2 lactylation promotes NCOA4-mediated ferritinophagy-ferroptosis by enhancing oxidative stress, thereby contributing to the cerebral IR injury in mice.

Objective:To evaluate the relationship between superoxide dismutase 2 (SOD2) lactylation and nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy-ferroptosis during cerebral ischemia-reperfusion (IR) in mice.Methods:Thirty-six clean-grade male C57BL/6 mice, aged 8-10 weeks, weighing 22-25 g, were divided into 4 groups ( n=9 each) using a table of random numbers: sham operation group (Sham group), cerebral IR group (IR group), IR+ glycolysis inhibitor 2-DG group (IR+ 2-DG group), and IR+ 2-DG+ NCOA4 overexpression group (IR+ 2-DG+ LvNCOA4 group). The model of cerebral IR injury was established by occlusion of the middle cerebral artery for 1 h followed by 24 h of reperfusion using the intraluminal suture method in anesthetized animals. 2-DG 250 mg/kg was intraperitoneally injected at 90 min before ischemia in IR+ 2-DG and IR+ 2-DG+ LvNCOA4 groups. The lentivirus overexpressing NCOA4 2 μl was injected into the ventricles at 7 days before ischemia in IR+ 2-DG+ LvNCOA4 group. The percentage of cerebral infarct volume was determined, the viable neurons were counted, and the levels of reactive oxygen species (ROS), malondialdehyde (MDA), and glutathione (GSH) were measured by enzyme-linked immunosorbent assay. The expression of SOD2, lysine 114 lactylation of superoxide dismutase 2 (SOD2-K114la), NCOA4, microtubule-associated protein 1 light chain 3β (LC3B), and acyl-CoA synthetase long-chain family member 4 (ACSL4) was determined by Western blot. Mitochondrial morphology was examined by electron microscopy. Results:Compared with Sham group, the percentage of cerebral infarct volume was significantly increased, the number of viable neurons was decreased, the levels of ROS and MDA were elevated, the content of GSH was reduced, the expression of SOD2-K114la, NCOA4, LC3B and ACSL4 was up-regulated, the expression of SOD2 was down-regulated ( P<0.05), and the mitochondrial injury was aggravated in IR group. Compared with IR group, the percentage of cerebral infarct volume was significantly decreased, the number of viable neurons was increased, the mitochondrial injury was alleviated, the levels of ROS and MDA were decreased, the content of GSH was increased, the expression of SOD2-K114la, NCOA4 and ACSL4 was down-regulated, and the expression of SOD2 and LC3B was up-regulated in IR+ 2-DG group ( P<0.05). Compared with IR+ 2-DG group, the percentage of cerebral infarct volume was significantly increased, the number of viable neurons was decreased, the levels of ROS and MDA were elevated, the content of GSH was reduced, and the expression of NCOA4, LC3B and ACSL4 was up-regulated ( P<0.05), no significant change was found in the expression of SOD2 and SOD2-K114la ( P>0.05), and the mitochondrial injury was aggravated in IR+ 2-DG+ LvNCOA4 group. Conclusions:SOD2 lactylation promotes NCOA4-mediated ferritinophagy-ferroptosis by enhancing oxidative stress, thereby contributing to the cerebral IR injury in mice.