Role Of Mitochondrial Aldehyde Dehydrogenase 2 On Cerebral Ischemia-reperfusion Injury In Rats Model And Its Mechanisms Investigation

Background:Ischemic stroke can cause the irreparable damage in a very short period of time due to brain cells in the state of ischemia and hypoxia.After the recovery of blood supply,it will aggravate the previous damage.Mitochondrial acetaldehyde dehydrogenase 2(ALDH2)participates in the pathophysiological processes in various diseases.Objective:The aim of our study is to investigate whether cytochrome c inhibitor i can protect brain cells against ischemia and reperfusion injury through activating of ALDH2 expression,and further to study the effect of ALDH2 gene overexpression on cerebral ischemia-reperfusion induced cell death.Method:Part A: Male SD rats were randomly divided into Sham group,I/R group,ALDH2 agonist Alda-1 + I/R group,and Bax channel blocker(Bcb)+ I/R group.The morphological changes of hippocampal CA1 cells were detected by HE staining method.The expressions of ALDH2 and NLRP3 were observed by immunohistochemistry,the protein expressions of NLRP3,IL-1β,Il-18,ALDH2 and4-HNE were examined by Western Blot.Part B: In order to further clarify the protective effect of ALDH2 on cerebral ischemia-reperfusion injury in rats,the rats were randomly divided into four groups:Sham group,I/R group,ALDH2 adeno-associated virus group(AAV9-ALDH2 + I/R),and ALDH2 adeno-associated virus + mitochondrial complex 1 inhibitor Rotenone group(AAV9-ALDH2 + I/R + Rotenone).The transfection of AAV9-ALDH2 was detected by immunofluorescence.The protein expressions of ALDH2 and NLRP3 in hippocampal CA1 cells were detected by immunohistochemistry,and the expressions of ALDH2,4-HNE and GSDMD were detected by Western Blot.Results:Part A: Compared with Sham group,the survival rate of hippocampal CA1 cells was decreased in I/R group(p < 0.01).Compared with I/R group,ALDH2 agonist Alda-1 and Bax channel blocker Bcb significantly increased the survival rate of hippocampal CA1 cells in I/R group(p < 0.01),NLRP3 protein expression was decreased and ALDH2 protein expression was increased(p < 0.01),while the expressions of IL-1β,IL-18 and 4-HNE were decreased and ALDH2 activity increased(p < 0.01).Part B: Compared with I/R group,the survival rate of hippocampal CA1 cells in AAV9-ALDH2 group was increased(p < 0.01).The expression of NLRP3 protein was decreased and ALDH2 protein was increased in AAV9-ALDH2 group and AAV9-ALDH2 + ROS activator Rotenone group(p < 0.01),the protein expressions of GSDMD and 4-HNE were decreased(p < 0.01).Conclusion:1.In rat global cerebral ischemia-reperfusion injury model,cytochrome c inhibitor play the protective role through promoting ALDH2 expression and decreasing NLRP3 expression and.2.The expression of NLRP3 inflammasome key protein was increased in rat global cerebral ischemia-reperfusion injury s model,overexpression of ALDH2 reduces the production of NLRP3 inflammasome and pyroptosis key proteins and play the protective role.