Mechanism Of Salvianolic Acid For Injection Mediated PIDD Pathway In Improving Ischemic Brain Damage In Rats

ObjectiveTo investigate the mechanism of Salvianolate(SLI)-mediated PIDD signaling pathway on improving cerebral ischemic damage in rats.MethodsForty healthy male Sprague-Dawley rats were randomly divided into 4 groups:sham operation group,model group,SLI group,and inhibitor group,10 rats in each group.The drug used in the inhibitor group was P53-induced death domain protein(A specific inhibitor of P53-induced protein with a death domain,PIDD),BubR1(Bub-ralated 1).In the sham-operated group,only the right common carotid artery,external carotid artery and internal carotid artery were isolated and no surgical treatment was performed.The other three groups were treated with modified suture method to prepare the right middle cerebral artery occlusion model(Middle cerebral artery occlusion,MCAO).After the model was successfully established,the SLI group was treated with salvianolic acid,the inhibitor group was injected with salvianolic acid and inhibitor,and the sham operation group and the model group were injected with the same amount of normal saline.Reverse transcription-polymerase chain reaction(RT-PCR)and Western blot were used to detect PIDD mRNA and protein expression change in brain homogenate at different time points(1 d,3 d,7 d)after ischemia-reperfusion in each group and the expression of caspase-2,t-BID,cytochrome-c and caspase-3 protein was observed 7 days after ischemiareperfusion.The neurological deficits were scored on the 1st,3rd,and 7th day after ischemia-reperfusion,and the modified neurological Severity Score(mNSS)was used.Brain tissue was taken by HE staining to observe the pathological changes of brain tissue,and TUNEL method was used to detect the apoptosis of nerve cells.Results1.Compared with the model group,the neurological deficit scores of the SLI group were significantly lower at 3 and 7 days(P < 0.01).Compared with the inhibitor group,the SLI group had high neurological deficit scores at 3 and 7 days.In the inhibitor group(P < 0.01);2.Compared with the sham operation group,the expression of PIDD mRNA and protein was significantly increased in the model group at 1d,3d and 7d(P < 0.01),and the expression of PIDD mRNA and protein at 1d,3d and 7d after ischemia and reperfusion in SLI group.The amount of PIDD mRNA was significantly lower than that of the model group(P < 0.01).The expression of PIDD mRNA and protein was higher than that of the model group at 1d,3d and 7d after ischemia-reperfusion.In the SLI group(P < 0.01),the PIDD mRNA was significantly lower than that of the Danshen group and the model group at 1 day after ischemia-reperfusion.3.Compared with the sham operation group,the expression of caspase-2,t-BID,cytochrome-c and caspase-3 protein in the model group was significantly increased at1 d,3d and 7d after ischemia-reperfusion(P < 0.01);SLI group The expressions of caspase-2,t-BID,cytochrome-c and caspase-3 at 3d and 7d after ischemia-reperfusion were significantly lower than those in the model group(P < 0.01),and the inhibitorgroup was 1d and 3d after ischemia-reperfusion.The expression of caspase-2,t-BID,cytochrome-c and caspase-3 protein in 7d was higher than that in the inhibitor group(P< 0.01).4.There was no obvious pathological changes in the morphology of nerve cells in the sham operation group on the 7th day after ischemia-reperfusion.There was no obvious edema and necrosis in the morphology of the nerve cells.The morphology was basically normal,the cell structure was relatively tight,and the arrangement was neat.TUNEL-positive cells were not found.The other three groups showed different degrees of neuronal apoptosis.The model group had more necrosis around the cerebral ischemia,the nerve cells were of different sizes,the arrangement was disordered,the deformation was atrophy,the neuron density was relatively low,and the inhibitor group was nerve.Apoptosis was the least,and the apoptotic index was significantly lower than that of the model group and the SLI group(P < 0.05).The apoptosis of the SLI group was between the inhibitor group and the model group,and the TUNEL positive cells were significantly lower than the model.Group(P < 0.05).Conclusion1.The expression of PIDD in brain tissue significantly increases after cerebral ischemic reperfusion injury in rats2.Salivary polyphenolic acid for injection can improve the neurological damage after cerebral ischemia-reperfusion,and may be related to the signaling pathway of PIDD/caspase-2/t-BID/cytochrome c /caspase-3 in rats.