Effect Of Histone Deacetylase On Hippocampal Neuronal Damage Induced By Cerebral Ischemia And Reperfusion In Rats

Hippocampus,regulating human memory and learning functions,for the limbic system of the brain.When cerebral ischemia occurs,the reduction of endogenous protective factors leads to the death of hippocampal neurons,but the neuron death in different regions of the hippocampus is inconsistent,and the cell death rate in CA1 region is the highestThis is differentially expressed in different regions of the hippocampus.The regulation of histones on chromatin is a precise process.After cerebral ischemia and reperfusion,it will lead to abnormal regulation of histones.Among them,acetylation is an important regulatory mechanism.The homology of yeast histone deacetylases is the source of HD AC classification,and their functions are different.About 18 members of the HD AC family in total can be divided into four types based on structural similarity.This kind of neuron death in different areas of the hippocampus is currently not fully studied from the perspective of epigenetics.This study investigated the differential expression and function of HD AC isoforms in hippocampal CA1,CA3 and DG regions after cerebral ischemia-reperfusion in ratsObjective:The transient cerebral ischemia-reperfusion model was used to group patients according to the requirements of different experiments.The changes of HD AC protein expression in hippocampal CA1,CA3 and DG regions were observed,and different selective HD AC inhibitors were injected intraperitoneally to observe the survival of neurons in different brain regions of hippocampusMethods:(1)Establishment a transient cerebral ischemia-reperfusion model in rats:A healthy male SD rat weighing between 260g and 280g was used.The Pusinelli four-vessel clamping method was used in this experiment because the ischemia was more obvious The experimental animals were randomly assigned.Rats in the I/R group were fasted for 8 hours before the operation,and were prepared for surgery.The rats were electrocoagulated on the bilateral vertebral artery.The next day,the common carotid artery was completely clamped by the experimental arterial clip,and the clamping time was fixed at 15 minutes.The entire process did not require anesthesia.The time point of sacrifice of successful experimental rats was 48h after the bilateral common carotid artery was clamped(2)Western blot detection of different HD AC subtypes in hippocampal neurons:The hippocampal tissue was taken out and divided into sections(CA1,CA3,DG),and the expression of HDAC1-HDAC11 in these three regions and the expression of phosphorylated HDACs were detected respectively(3)Intraperitoneal injection of HDACs inhibitors:Intraperitoneal injection of different types of specific HDAC inhibitors(HDACli,HDAC2i,HDAC3i,HDAC4i,HDAC7i),two injections,respectively,before the common carotid artery is clamped and after the common carotid artery is clamped After normal feeding,the brain tissue was removed for 48 hours(4)The survival of hippocampal neurons after the action of specific HDACs inhibitors was detected by Nissl staining:different selective HDAC inhibitors were injected into rats by intraperitoneal injection,and perfusion was performed 48 hours later Observe hippocampal neuron survivalResults:(1)The results of Western blot showed that in the I/R group,in the non-phosphorylated HDACs subtypes,only the expression level of HDAC4 in the hippocampal CA1 region was higher than that in the sham group,and it was higher than that in the CA3 region.The difference was statistically significant.Significance;Among the phosphorylated HDACs subtypes,phosphorylated HDAC1,2,3,4 and 7 are higher in CA1 and CA3 than in sham group,the difference is statistically significant.There were no significant differences;there was no significant difference in the expression of phosphorylated and non-phosphorylated HD AC isoforms in the hippocampal DG region(2)Nissl staining results showed that in the administration group,the survival rate of neurons in the hippocampal CA1 region was higher than that in the control group(P<0.01)Conclusion:(1)The expression levels of HDACs in the hippocampus of rats after cerebral ischemia-reperfusion were different.Among them,the expression levels of non-phosphorylated HDAC4 and phosphorylated HDAC1,2,3,4,7 increased in CA1 region(2)Selective inhibition of HDAC1,2,3,4,and 7 can improve the survival rate of neurons in CA1 region of cerebral ischemia rats.