Silencing of ALOX15 reduces ferroptosis and inflammation induced by cerebral ischemia-reperfusion by regulating PHD2/HIF2 alpha signaling pathway

Objective: To investigate the potential mechanism of arachidonic acid deoxyribozyme 15 (ALOX15) in ferroptosis and inflammation induced by cerebral ischemia reperfusion injury. Methods: The mice and cell models of cerebral ischemiareperfusion injury were constructed. Western Blot was used to detect the protein expression levels of ALOX15, glutathione peroxidase (GPX4), hypoxia-inducible factor-2a (HIF-2a), prolyl hydroxylase (PHD) and inflammatory factors (NLRP3, IL-1 ss, IL18) in brain tissues and cells. Cell proliferation activity was detected by CCK-8 method. LDH assay was used to detect the release of lactate dehydrogenase. TTC staining was used to observe cerebral infarction. Results: In cerebral ischemia-reperfusion mice and cell models, the expression of ALOX15 protein was increased, the expression of GPX4, a key marker of ferroptosis was decreased, and silencing of ALOX15 down-regulated the GPX4 expression. HIF-2a expression was down-regulated in animal and cell models of cerebral ischemia reperfusion, and silencing of ALOX15 increased the HIF2a expression by inhibiting PHD2 expression. Inhibition of ALOX15 expression reduced inflammatory factors levels (NLRP3, IL-1 ss, and IL-18) in cerebral ischemia. Inhibitor of PHD2 (IXOC-4) alleviating brain injury and cell death induced by cerebral ischemia reperfusion and stabilize HIF-2a expression in vivo. Conclusion: The expression of ALOX15 was up-regulated in cerebral ischemia-reperfusion animals and cells model. Inhibition of ALOX15 up-regulated the GPX4 expression, and promoted HIF-2a expression by inhibiting PHD2, thus alleviating ferroptosis and inflammation caused by cerebral ischemia-reperfusion injury.