The Expression Of TLR4 And TLR3 In Brain Tissue Of Rats After Cerebral Ischemia/reperfusion

Objective To investigate the expression of Toll-like receptor 4(TLR4)、Toll-like receptor 3 (TLR3) and to preliminary study the effect of TLR4 TLR3 on neuronal deficits,pathology,ischemic injury and neuronal apoptosis after Cerebral Ischemia/reperfusion in Rats.Metheods The healthy male Sprague-dawley rats weighing 260-380g were randomly divided into two groups:sham-operated group(n=24) and ischemia/reperfusion model group(n=24).The middle cerebral artery occlusion(MCAO) models were established by using the intraluminal suture occlusion method in ischemia/reperfusion model group rats.All rats were randomly divided into four sub-groups as follows:6h,12h,24h,48h treatment groups according to the killing time after ischmia/reperfution.Each sub-group included six rats. Then, neurological behavior evaluation was performed by the method of Longa’s scoring.The changement of neuronal deficits accepted dynamic observation. The Pathologic changes were observed by hematoxylin and eosin(HE). Meanwhile,the expression of TLR4、TLR3 were measured with methods of immunohistochemistry. Apoptotic cells in ischemia/ reperfusion rat brains were detected by TUNEL assay.Results1. The expression of TLR4、TLR3 in the sham-operated group had no significant neuron deficits.The expression in ischemic part of model groups reached the peak at the time point of 24 hours after reperfusion(P <0.05).Compared with the sham-operated group, the expression of TLR4、TLR3 significantly increased in model group at the same time point (P<0.05). Besides,the expression of TLR4、TLR3 in ischemic penumbra significantly increased at the same time point compared with the expression in the ischemic core zone(P<0.05).2. Few apoptotic cells were detected in the sham-operated group.The peak of Apoptotic cells’numbers in ischemic part of model groups appeared at 24h after reperfusion(P<0.05). The amount of apoptotic cells in model group significantly increased at the same time point compared with sham-operated group(P<0.05).Meanwhile,Compared with the amount of apoptotic cells in the ischemic core zone,the apoptotic cells in ischemic penumbra significantly increased at the same time point(P<0.05).ConclusionThe up-regulating expression of TLR4、TLR3 after the focal cerebral ischemia/reperfusion in rats suggested that TLR4、TLR3 played a certain role in ischemic inflammatory injury and the pathophysiological process of neuronal deficits induced by ischemia/reperfusion.