Acid sphingomyelinase inhibitor reduces ferroptosis by upregulating Sirt3 to attenuate brain damage in ischemia-reperfusion

• 1、Emergency Department,The Second Affiliated Hospital of Soochow University,SuZhou 215004

Abstract：Background: Inhibition of acid sphingomyelinase (ASM) after stroke has been shown to have cerebroprotective effects, but the underlying mechanisms remain unclear. Purpose: This study aimed to investigate whether the ASM inhibitor desipramine (Des) attenuates neuronal ischemia/reperfusion (I/R) injury by inhibiting ferroptosis. Methods: A mouse model of transient middle cerebral artery I/R injury was established, and Des (10 mg/kg) was injected intraperitoneally during reperfusion. An oxygen glucose deprivation/re-oxygenation HT22 neuronal injury model was established, and the cells were treated with Des, exogenous ceramides, or a Sirtuin3 (Sirt3) inhibitor (3-(1H-1,2,3-triazol-4-yl) pyridine) during re-oxygenation. The volume of cerebral infarction was determined by 2,3,5-triphenyltetrazolium chloride staining, neuronal injury was assessed by Nissl staining, cell viability was assessed by the CCK-8 assay, oxidative stress indicators were determined using commercial kits, and ferroptosis-related proteins were detected by western blotting and immunofluorescence. Results: Des protected against both I/R-induced brain tissue damage and OGD/Re-induced neuronal damage. Both Des and ASM knockdown reduced ceramide production, inhibited glial cell activation, and attenuated neuronal oxidative stress levels and ferroptosis after brain injury, whereas the addition of exogenous ceramides exacerbated ferroptosis. Sirt3 inhibition significantly reduced the inhibitory effect of ASM knockdown on neuronal ferroptosis. Conclusion: Des attenuates ferroptosis in cerebral I/R injury by maintaining redox homeostasis by upregulating Sirt3 levels via ASM/ceramide pathway inhibition.

Keywords： emergency medicine cerebral ischemia-reperfusion injury acid sphingomyelinase Sirt3 ferroptosis