The Relationship Between MiR-27a Expression Changes And Ferroptosis In Ischemia Reperfusion Injury Of Rat Brain

Objectives To investigate the relationship between miR-27 a and ferroptosis and its potential mechanism in cerebral ischemia reperfusion injury model in rats.Methods 108 male Sprague Dawley rats(250-280g)were randomly divided into control group(6 rats),sham group(12 rats),model group(MCAO/R group).According to different ischemia reperfusion time,the model group was divided into ischemia reperfusion 3h(6rats),ischemia reperfusion 6h(6 rats),ischemia reperfusion 12h(6 rats)and ischemia reperfusion 24 h group(12 rats),and negative control group(Vehicle group)(12 rats),agomir-27 a group(12 rats),antagomir-27 a group(12 rats),agomir-27a+DMSO group(12rats),and agomir-27a+Fer-1 group(12 rats).Zea-Longa score was used to evaluate nerurological score.2,3,5 triphenyl tetrazolium chloride(TTC)staining was used to evaluate the infarct volume.The relative expression level of miR-27 a was detected by q RT-PCR.The relative expression levels of glutathione peroxidase 4(GPx4)and solute carrier family 7,member 11(SLC7A11)proteins were detected by Western Blot.The contents of GSH,Fe and MDA were detected by GSH,Fe and MDA detection kits.The target gene of miR-27 a was confirmed by dual luciferase reporter gene technique.Results 1 The rats included in the experiment all reached the standard of model success,the model success rate was 85.7%,and the model mortality rate was 14.3%.2 There was no obvious change in the nerurological score between the sham group and the control group(P>0.05).In contrast with the control group,the model group showed obvious neurological impairment and higher nerurological score(P<0.05),the nerurological score increased at 3h reperfusion,and reached the highest level at 24 h reperfusion.3In contrast with the control group,no significant change was found in the expression of miR-27 a and the protein SLC7A11(P>0.05).In contrast with the sham group,the expression of miR-27 a significantly increased in the model group(P<0.05),began to increase at 3h reperfusion,and reached the peak at 24 h reperfusion,the relative expression level of SLC7A11 protein in the model group significantly decreased(P<0.05),began to decrease at3 h reperfusion,and reached the lowest point at 24 h reperfusion.4 Measurement items showed no significant change between the sham group and the control group(P>0.05);In contrast with the sham group,the level of GPx4 protein and the content of GSH obviously decreased in the model group(P<0.05),GPx4 protein relative expression and GSH content decreased at 3h reperfusion(P<0.05),reaching the bottom at 24 h reperfusion;In contrast with the sham group,in the model group the contents of Fe and MDA obviously rised(P<0.05),started to increase at 3h reperfusion,and reached the top at 24 h reperfusion.5 Measurement items showed no significant change between the MCAO/R group and the vehicle group(P>0.05);Compared with the vehicle group,the level of GPx4 protein and the content of GSH obviously decreased(P<0.05),the content of MDA and Fe evidentily rised(P<0.05)in the agomir-27 a group;In contrast,compared with the vehicle group,the levels of GPx4 protein and GSH significantly increased in the antagomir-27 a group,while the content of MDA and Fe obviously declined(P<0.05).Relative to the the vehicle group,agomir-27 a increased neurologic score and cerebral infarct volume(P<0.05),and antagomir-27 a decreased neurological score and cerebral infarct volume(P<0.05).6 In dual luciferase reporter gene technique,miR-27 a mimics significantly inhibited luciferase activity in wild-type SLC7A11-WT plasmids transfected with SLC7A11 m RNA 3’-UTR region without mutation(P<0.05).In contrast with the vehicle group,the level of SLC7A11 protein declined in the agomiR-27 a group(P<0.05).7 Measurement items showed no significant change between the agomiR-27 a group and the agomiR-27a+DMSO group(P>0.05).Compared with the agomiR-27a+DMSO group,in the agomir-27a+Fer-1group the levels of GPx4 and GSH increased(P<0.05),however,the content of Fe and MDA declined(P<0.05).Compared with the agomiR-27a+DMSO group,neurologic score and cerebral infarct volume decreased in the agomir-27a+Fer-1 group(P<0.05).Conclusions 1 miR-27 a and ferroptosis are involved in the pathological process of cerebral ischemia reperfusion injury.2 In the process of cerebral ischemia and reperfusion,miR-27 a may induce ferroptosis through SLC7A11,thus causing brain tissue damage.Figure32;Table35;Reference 147...