| Objective To investigate the role and mechanism of mi RNA-27 a in regulating ferroptosis in ischemic stroke rats.Methods Ischemic cerebral apoplexy rat model was established by thread embolism method.Eight weeks SPF male SD rats were randomly divided into control group,sham operation group,MCAO group(according to different ischemia time,rats were divided into 6h,12 h,24h and 48 h ischemia groups),ischemic 48h+DMSO group(I 4h+DMSO),I48h+Ferrostatin-1 group(I 48h+Fer-1),I 48h+negative control group(I 48h+NC),I48h+mi RNA-27 a agonist group(I 48h+ago-mi RNA-27a)and I 48h+ mi RNA-27 a inhibitor group(I 48h+antago-mi RNA-27a).Neural function score was used to assess the behavior disorder of rats.TTC staining was used to evaluate the degree of brain tissue damage in rats.Glutathione peroxidase 4(GPX4),glutathione(GSH),iron and malondialdehyde(MDA)are ferroptosis biomarkers.The expression of GPX4 and Nrf2 in rat brain tissue was analyzed by Western blot;The contents of GSH,iron and MDA in brain tissues were detected by the glutathione test kit,iron test kit and MDA test kit;The expression of mi RNA-27 a was analyzed by q RT-PCR;The targeting relationship between mi RNA-27 a and Nrf2 was analyzed by dual luciferase reporter assay.Results 1 Compared with the sham group,neurological function score of rats in the model group increased(P < 0.05).2 There was not any significant change in the sham group compared with the control group(P > 0.05).Compared with the sham group,GPX4 and GSH expressions were decreased in the model group(P < 0.05)and reached the minimum value at 48 h after ischemia in this study;Contents of MDA and iron were increased(P < 0.05)and reached the highest value at 48 h in this study.3 There was no significant change in results in the I 48h+DMSO group compared with the I 48 h group,(P > 0.05).Compared with I 48h+DMSO group,the expressions of GPX4 and GSH were increased in I 48h+Fer-1 group,while the contents of MDA and iron were decreased,and the neurological score and cerebral infarct size of rats were decreased(P < 0.05).4Compared with the sham group,the expression of mi RNA-27 a in the model group increased and reached the maximum value at 48 h in this study;There was no significant change in the results in the I 48h+NC group compared with the I 48 h group(P > 0.05).Compared with the I 48h+NC group,the expression of mi RNA-27 a was increased in the I48h+ago-mi RNA-27 a group(P < 0.05);The expression of GPX4 and GSH decreased(P< 0.05),while the contents of iron and MDA in brain tissue increased(P < 0.05);Meanwhile,neurological score and cerebral infarct size increased in rats(P < 0.05).Results in the I 48h+antago-mi RNA-27 a group were contrary to those in the I 48h+agomi RNA-27 a group(P < 0.05).5 Compared with the sham group,the expression level of Nrf2 in the model group decreased,contrary to the trend of mi RNA-27 a,and reached the lowest value at 48 h of this study;In the dual luciferase reporter technique,luciferase activity decreased significantly in WT Nrf2+mi RNA-27 a group compared with WT Nrf2+NC group(P < 0.01),but there was no significant change in luciferase activity in MT Nrf2+NC group and MT Nrf2+mi RNA-27 a group;Western blot analysis showed that the expression of Nrf2 was further reduced in the I 48h+ago-mi RNA-27 a group compared with the I 48h+NC group.Western blot results showed that the expression of Nrf2 protein was increased in the group I 48h+antago-mi RNA-27 a.Conclusion 1 Ferroptosis is involved in the pathological process of brain tissue injury in ischemic stroke.2 mi RNA-27 a can promote the occurrence of ferroptosis,and further aggravate the brain tissue damage in ischemic stroke,which may be mediated by inhibiting the expression of Nrf2.Figure 32;Table 27;Reference 154... |
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