Puerarin Regulates JAK2/STAT3 Pathway And Affects Cell Apoptosis After Cerebral Ischemia-reperfusion Injury In Rats

Objective To investigate the role of JAK2 / STAT3 signaling pathway,and explore the regulation,the anti-apoptosis neuroprotective mechanism of the puerarin on this pathway in cerebral ischemia-reperfusion injury in rats.To provide the experimental theory basis of the application of puerarin in the prevention and treatment in cerebral ischemia reperfusion injury.Methods To select a total of 180 SPF male Sprague-Dawley rats,then were divided into three groups: sham-operation group(36 rats),ischemia reperfusion group,and puerarin group(each of group was 72 rats)according to random number table method(Note: Adding enough of rats in the process of building up were eliminated with the principle of random).The ischemia reperfusion group and puerarin group rats used the line plug to prepare left MCAO ischemia reperfusion model.After pretreating,the Longa scoring system was used to determine the neurologic impairment score,TTC staining was used to measure cerebral infarct volume,the TUNEL method was used to measure the apoptosis of neural cells,and immunohistochemistry and RT-PCR method was used to measure the expression of P-JAK2?P-STAT3?P53 protein and mRNA in hippocampal after pretreating at 2 hours of cerebral ischemia and 6 hours,24 hours,72 hours of reperfusion.Results1.The rats of sham-operation group waked activity,no neurologic deficits symptoms,not seen white infarcts,accidentally see scattered distribution of a small number of apoptotic cells and a small amount expression of P-JAK2,P-STAT3 and P53 protein and mRNA.There was no significant difference between the three time points of 2 hours of cerebral ischemia and 6 hours,24 hours,72 hours of reperfusion,and were no statistical significance(P > 0.05).2.Compared with sham-operation group,ischemia reperfusion group and puerarin group rats were different degree of nerve function defect,clearly visible white infarcts,and the number of apoptotic cells increased,the expression P-JAK2,P-STAT3 and P53 protein and mRNA were higher in bilateral hippocampal tissue ischemia.All of the differences were statistically significant(P < 0.05).3.Compared with ischemia-reperfusion group,the neural function defect scale of puerarin group was falled,the infarct size and number of apoptosis positive cells were obviously reduced,the expression of P-JAK2,P-STAT3 and P53 protein and mRNA decreased significantly in bilateral hippocampal tissue ischemia.All of the differences were statistically significant(P < 0.05).4.In three time points of 2 hours of cerebral ischemia and 6 hours,24 hours,72 hours of reperfusion,the nerve function defect score no obvious difference was found between each point in time of ischemia reperfusion group compared with puerarin group,and all of the differences were not statistically significant(P > 0.05).In 24 hours of reperfusion,the number of apoptotic cells were maximum,the area of white infarcts were maximal,and the expression of P-JAK2,P-STAT3 and P53 protein and mRNA were largest in bilateral hippocampal tissue ischemia.And gradually reducing in 72 hours of reperfusion,but higher than 6 hours of reperfusion.All of the differences were statistically significant(P < 0.05).Among them,the change trend of the expression of P53 protein and mRNA were consistent with P-JAK2,P-STAT3 protein and mRNA.Conclusion The expression of P-JAK2 and P-STAT3 protein and mRNA rised after cerebral ischemic reperfusion injury.To speculate that JAK2 and STAT3 was activated after cerebral ischemia reperfusion and participated in the brain tissue damage in the phosphorylated form.One of the brain protection mechanism of puerarin is probably to inhibite the abnormal activation of JAK2/STAT3 signaling pathway and resist the nerve cells apoptosis.