Effect Of Procyanidin On Expression Of GRP78, CHOP And Caspase-12the Molecules Related ERS In The Rats With Cerebral Ischemia Reperfusion

ObjectiveTo investigate cerebral ischemia and reperfusion injury in hippocampalneurons in programmed cell death in the endoplasmic reticulum stressmechanism and the content of the classical endoplasmic reticulum stressmarkers GRP78,CHOP and Caspase-12in hippocampus CA1areas of rats withcerebral ischemia reperfusion(IR) and effects of procyanidin(PC) on it, toprovide theoretical evidence for its clinical application.Methods180SD rats were divided into sham-operation group,I/R group and PCgroup.Every group have60rats. PC group was given PC orally for one weekbefore surgery.Respectively after IR3h,6h,12h,24h and48h the rats werekilled.Observed at different time points in rats neurobeharioralperformance.Used Nissl staining observe the pathological changes. usedTUNEL to evaluate neuronal apoptosis, the expression of GRP78,CHOPandCaspse-12protein in hippocampus of rats were examined byimmunohistochemistry and Western-blot method at different time, and theexpression of GRP78,CHOP and Caspase-12mRNA in hippocampus of ratswere examined by RT-PCR method at different time. Results1.Neurological score:Compared with the PC group, the symptoms ofneurological deficit in rats of model group is obvious(p<0.01).2.Pathological observation of brain tissue: Nissl body in the sham-operatedgroup is clear. By staining the Nissl body was massive, large and quantity.Itreflect that the function of the protein synthesis in nerve cells is powerful.Nisslbody in the model group and PC group all reduce or even dispear.Model groupcompare with sham-operated group at each time point,Nissl body are reduce ordisappear.PC group compare with sham-operated group at each timepoint,Nissl body are reduce, but compare with Model group,the Nissl body in theneuronal cell increase obviously.Neuronal cell damage is significiantlyimproved.3.TUNEL method: The number of TUNEL positive neuron is seenaccidentally in the sham-operated group.After cerebral ischemia andreperfusion, Nerve cell apotosis can be seen in Model group and PC group.After cerebral ischemia and reperfusion3h,Model group compare with PCgroup,the number of TUNEL positive neuron have no sigificent difference.In theother points,the number of TUNEL positive neuron in the Model group are allhigher than the PC group.4.Immunohistochemistry,Western-blot and method:In the sham-operatedgroup,the expression of GRP78, CHOP and Caspase-12are very low.Comparewith the sham-operated group the expression of GRP78, CHOP andCaspase-12are increased in the Model group and PC group(p<0.01).Theexpression of GRP78reched its peak at12h after ischemia and reperfusion,theexpression of the intensity gradually decreased with time,GRP78expressioninthe PC group was higher than model group(p<0.05, p<0.01). CHOP expressionis not obvious at3h after ischemia and reperfusion,gradually increased ay 6h,peaked at24h, then decreased gradually, at each time point the PC groupwas lower than the Model group, have signicant different(p<0.05,p<0.01).Caspase-12begin to increase6hours, which reach the peak24hours;Caspase-9begin to significantly rise after6hours, reach the peak24hours, ateach time point the PC group was lower than the Model group,have signicantdifferent(p<0.05，p<0.01).Conclusions1.ERS that ischemia and reperfusion tiggerred may be an importantmechanism of cerebral ischemia and reperfusion injury in hippocampal neuronsprogrammed death.3.PC may reduce the number of apotosis of hippocampal neurons incerebral ischemia and reperfusion injury.3.PC can decreased the expression of CHOP,caspase-12and inincreaseGRP78expression.4.PC can block the apoptotic path way triggered by the ERS.