Expression of S1P1 in focal brain ischemia-reperfusion rats

Objective To observe the expression of sphingosine-1-phosphate receptor 1(S1P1) in rats with focal brain ischemia-reperfusion and clarify the effect of S1P1 on brain ischemia-reperfusion injury.Methods Male Wistar rats were randomly divided into sham-operated group and ischemia-reperfusion groups.The model of focal brain ischemia-reperfusion injury was induced by middle cerebral artery occlusion(MCAO).After 2hof ischemia and 3h,6h,12h and 24h of reperfusion,the animals were sacrificed.Ten minutes prior to reperfusion,animals suffered with 24h reperfusion were administered vehicle or FTY720(1 mg per kg body weight) which was the agonist of s1p receptors intravenously.Immunohistochemistry was used to detect the level of S1P1 protein expressions.Neurological score,TTC and TNUNEL were used to detect the effect of FTY720.Results Compared with sham-operated group,ischemia-reperfusion significantly increased the expression of S1P1 in the peri-infarct cortex surrounding the primary infarct which began at 3h after reperfusion(P0.05),peaked at 12h and subsided at 24h.FTY720 significantly improved neurological score and reduced infarct volume and TUNEL-positive cells at 24h after MCAO.Conclusions This study indicates that S1P1 is activated and neuroprotective during the course of focal brain ischemia-reperfusion.