Expression of HSP70,c-fos following focal cerebral ischemic reperfusion in rats and neuroprotective effect of Cudrania tricuspidata

Objective To investigate the expression of heat shock protein 70(HSP70) and c-fos,the presence of apoptosis and the neuroprotective effects of Cudrania tricuspidata root extrate(Ecr) after focal cerebral ischemic reperfusion in rats.Methods Models of middle cerebral artery occlusion(MCAO) were used in this study.The rats in Ecr pretreated ischemia reperfusion(IR) group were fed with Ecr(2 ml tid) for 5 days before MCAO.The brain specimen were took at different reperfusion times: 1 h,6 h,12 h,24 h,3 d and 7 d after recirculation.Then immunohistochemistry,insitu hybridization,terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL) were used to detect the expression of HSP70,c-fos gene and cell apoptosis in the brains.Positive results were semiquantitatively analyzed.Results IR could induce the expression of HSP70 and c-fos.HSP70 was detected at 6 h following reperfusion and peaked at 24 h both in cortical and basal ganglia regions.c-fos was markedly expressed at 1 h and the level peaked at 6 h in the ischemic hemispheres,and then reduced gradually.The TUNEL positive cells were markedly observed at 6 h.After treatment with Ecr,the positive reaction cells both of HSP70 and c-fos were significantly increased(all(P)0.01) and TUNEL positive cells were obviously reduced.Conclusion HSP70 and c-fos may be involved in pathophysiologic process of cerebral ischemia.Ecr may play neuroprotective roles for ischemical reperfusion injury.