Relationship Between Cerebral Ischemia-reperfusion Injury And Expression Of Autophagy Associated Protein Beclin-1 And Cathepsin B

Objective: Cerebral infarction is the most common neurological disease.To restore blood supply as soon as possible can reduce ischemic injury.And ischemia-reperfusion injury can be observed to further aggravate the dysfunction of nerve cells,which can lead to poor prognosis.To avoid ischemia-reperfusion injury,and to improve the prognosis of patients with acute cerebral infarction,has a greater research value.Previous studies used pretreatment model mostly to study ischemia-reperfusion injury.It is unable to predict when ischemic stroke come in clinical.In this study,the rat model of middle cerebral artery occlusion(MCAO)was established by the method of thread occlusion and Further induction of autophagy with rapamycin during ischemia.To observe the difference of nerve function defect and the expression of the autophagy associated protein Beclin-1,Cathepsin B in different treatment groups.,to explore the role of autophagy on ischemia-reperfusion injury.Methods: Forty-five Wistar rats were randomly divided into Sham group,I / R group,RAPA group,15 rats in each group.The rats in RAPA group were given Intraabdominal injection of rapamycin at the same time.Rats in I / R group and RAPA group were reperfused 2h after cerebral ischemia,and after 24 h using longa neurological deficit score to evaluate.And to observe the cytopathological changes at ischemic brain tissue HE staining in 400 times the light microscope.And the protein expression of measuring ischemic cortex autophagy-related protein Beclin-1 and Cathepsin B were tested by Western blotting.Results: There was no symptom of nerve function defect in Sham group and I / R group had different degrees of nerve function defect.In I / R group,the degree of nerve function defect was the most serious,and that in RAPA group was the most serious.There was significant difference in the expression of Beclin-1,Cathepsin B of the ischemic brain tissue of rats in Sham group and in the I / R group.The expression of neurons in RAPA group was significantly higher than that in the I / R group.The neuronal morphology,cell membrane and nucleus were intact,and there was Nissl corpuscle in RAPA group.No pathological changes.The number of neurons in group I / R was irregular,the number of neurons decreased,the cytoplasm of a large number of neurons was deep stained,nuclear pyknosis,partial dissolution,and the disappearance of Nissl bodies in the cytoplasm.The number of neurons was between Sham group and I / R group,some neurons were pyknosis and nucleolysis.Conclusion: 1)I / R can cause brain damage and increase the level of autophagy in the corresponding area.2)During cerebral ischemia in rats,using rapamycin to activate autophagy,which alleviated neurological impairment and brain cell damage by up-regulating the expression of Beclin-1 and Cathepsin B.Activation of autophagy during ischemia has obvious neuroprotective effect on ischemia reperfusion rats.