腺苷预处理通过增加GSK-3β磷酸化水平减轻大鼠脑缺血再灌注损伤

Adenosine preconditioning alleviates cerebral ischemia-reperfusion injury in rats by increasing GSK-3βphosphorylation levels

目的观察腺苷预处理对脑缺血-再灌注(IR)损伤后大鼠海马组织内神经元核抗原(NeuN)、微管相关蛋白2(MAP2)、神经元特异性烯醇化酶(NSE)、磷酸化糖原合酶激酶3β(p-GSK-3β)和糖原合酶激酶(GSK-3β)表达的影响,探讨腺苷对大鼠IR的保护机制。方法将27只雄性Sprague Dawley大鼠随机分为假手术组(Sham组)、缺血再灌注组(IR组)和腺苷预处理(AP组),每组9只,IR组和AP组建立大脑中动脉闭塞(MCAO)模型。采用5分制神经行为学评分标准对大鼠进行评分;以TTC染色法观察各组大鼠脑梗死情况,并计算脑梗死体积比例,免疫荧光法检测各组大鼠脑组织中p-GSK-3β的表达,Western blot法检测各组大鼠脑组织中NeuN、MAP2、NSE、p-GSK-3β和GSK-3β的表达。结果与Sham组比较,IR组大鼠神经功能评分和脑梗死体积比例明显增高(P<0.01),IR组p-GSK-3β、NeuN、MAP2、NSE的表达水平及p-GSK-3β/GSK-3β比值明显降低(P<0.05);与IR组比较,AP组大鼠神经功能缺损评分和脑梗死体积比例降低(P<0.05),p-GSK-3β、NeuN、MAP2、NSE的表达水平及p-GSK-3β/GSK-3β的比值升高(P<0.05)。结论腺苷预处理可能通过提高GSK-3β磷酸化水平,保护IR损伤中的神经元。

Objective To observe the effect of adenosine preconditioning on the expression of neuron specific nuclear protein(NeuN),microtubule-associated protein 2(MAP2),neuron-specific enolase(NSE),phospho-glycogen synthase kinase-3β(p-GSK-3β)and glycogen synthase kinase-3β(GSK-3β)in the hippocampal tissue of rats after cerebral ischemia-reperfusion(IR)injury,and to explore the protective mechanism of adenosine against cerebral ischemia-reperfusion injury in rats.Methods Twenty-seven male Sprague Dawley rats were randomly divided into Sham group,IR group,and adenosine preconditioning group(AP group),with 9 rats in each group.Middle cerebral artery occlusion model(MCAO)was established in IR and AP group.Nine rats in each group were divided into three groups.The rats were scored on a 5-point neurobehavioral scale;TTC staining was used to observe the cerebral infarction of rats in each group,and the volume proportion of cerebral infarction was calculated;The expression of p-GSK-3βin the brain tissue of each group was detected by immunofluorescence.The expression of NeuN,MAP2,NSE,p-GSK-3β,and GSK-3βin the rat brain tissue of each group was detected by Western blot.Results Compared with the Sham group,the neurological function score and the volume ratio of cerebral infarction in IR group increased significantly(P<0.01),while the expression levels of p-GSK-3β,NeuN,MAP2 and NSE and the ratio of p-GSK-3β/GSK-3βdecreased significantly(P<0.05)in IR group.Compared with IR group,the neurological deficit score and cerebral infarction volume ratio in AP group decreased(P<0.05),and the expression levels of p-GSK-3β,NeuN,MAP2 and NSE and the ratio of p-GSK-3β/GSK-3βincreased in AP group(P<0.05).Conclusions Adenosine preconditioning may protect neurons in cerebral ischemia-reperfusion injury by increasing the phosphorylation level of GSK-3β.