Neuroprotective Effect And Mechanism Of Ferrostatin-1 In Rat Model Of Subarachnoid Hemorrhage

Background and purposes: Subarachnoid hemorrhage(SAH)is a common cerebrovascular emergency in the nervous system.The most common cause is rupture of intracranial aneurysms.Despite advanced development of aneurysm clipping,endovascular treatment and intensive care treatment,the mortality and morbidity rates of SAH patients still remain high.Studies suggest that early brain injury may be one of the leading causes of death and poor prognosis of SAH patients.Ferroptosis is a new type of cell death proposed in 2012,which may be involved in the development of early brain injury in SAH.The inhibition of ferroptosis has been shown significant protection in many disease models.Ferroptosis is regulated by amino acid metabolism and iron metabolism,and finally through generation of reactive oxygen species(ROS)leading to cell death.Ferrostatin-1(Fer-1),a antioxidant small molecule,is found as a potent inhibitor of ferroptosis containing aralkylamine which attenuates ferroptosis by inhibiting lipid peroxidation.However,whether inhibition of ferroptosis by Fer-1 in SAH would attenuate early brain injury remain unclear.Therefore,the aims of this study was to address the role of ferroptosis in SAH,and to discover the effect and mechanism of Fer-1 by inhibiting ferroptosis in SAH.Methods:(1)Rat SAH model was established by intravascular puncture.Transmission electron microscopy was used to identify the type of cell death,and iron staining was employed to discover iron level in brain.The reliable evidence of iron death in brain tissue after SAH was obtained.(2)Animals were randomly divided into control group,sham group,SAH group,SAH+Fer-1 group and SAH+DMSO group.A single dose of Fer-1 or DMSO was injected into the lateral ventricle 30 minutes after intravascular puncture.The neuroprotective effect of Fer-1 was evaluated by assessing the degree of cerebral hemorrhage,neurological status,Evans blue detection,and cerebral edema in each group of animals.(3)In the study of the neuroprotective mechanism of Fer-1,the expression level of Prdx6 in brain tissue of each group was detected by Western blot and reverse transcription-quantitative real-time PCR(RT-qpcr).Oxidative stress levels were evaluated by detecting malondialdehyde(MDA)and glutathione peroxidase(GSHPx).Results:(1)Transmission electron microscopy showed mitochondrial membrane thickening and mitochondrial palsy,and iron staining showed a large amount of iron deposition in the cerebral cortex.(2)Injection of a single dose of Fer-1 into the lateral ventricle can significantly improve the blood-brain barrier destruction after SAH,reduce brain edema,and promote the recovery of nerve function.(3)Compared with the sham group,the expression levels of Prdx6 and glutathione peroxidase were decreased in the SAH group and the SAH+DMSO group,and the MDA level was increased.Compared with the SAH group,SAH+Fer-1 The expression level of Prdx6 and the level of glutathione peroxidase in group 1 were significantly increased,and the level of MDA was significantly decreased.Conclusions: At 24 h after SAH,there is ferroptosis in the cerebral cortical cells.Cerebral ventricular injection of iron death inhibitor Fer-1 treatment can significantly reduce brain edema after SAH in rats,improve blood-brain barrier permeability,and promote the recovery of nerve function.The results showed that Fer-1 can reduce the degree of early brain injury after SAH.Moreover,Fer-1 plays a neuroprotective role in the early brain injury after SAH by promoting the expression of PRDX6 molecule and reducing the level of oxidative stress.