Ischemic postconditioning down-rugulate expression of TLR4 and NF-кB during cerebral ischemla/reperfusion in Rats

Objective To investigate the effects of ischemic postconditioning on the expression of Toll-like receptor 4(TLR4) and Nuclear factor-кB(NF-кB) during focal cerebral ischemic reperfusion in rats.Methods One hundred and ten adult healthy male Sprague-Dawley rats were randomized into sham group(n=10),ischemic reperfusion group(I/R group) and ischemic postconditioning group(IP group).The latter two groups were equally divided into five subgroups according to different time points of the ischemic reperfusion(6,12,24,48 and 72h)(n=10,respectively).Both focal cerebral ischemic reperfusion and ischemic postconditioning was established.The neurobehavioral function deficit scores,infarct volume and the expression of TLR4 protein,NF-κB protein,TLR4 mRNA and NF-κB mRNA in the frontoparietal cortex at the corresponding time points were observed.Results Compared with the I/R group,the IP group showed improved neurobehavioral function deficit scores and reduced cerebral infarct volume(P0.05).TLR4 protein and NF-κB protein expression significantly increased in I/R group and IP group at 6h following reperfusion,peaked at 24h,however,the positive products in IP group were significantly lower than those in I/R group at each time point after reperfusion(P0.05).TLR4 mRNA and NF-κB mRNA expression were consistent with TLR4 protein and NF-κB protein.Conclusion IP could reduce infarct volume and improve neurobehavioral function through inhibiting the expressions of TLR4 and NF-κB.