跑台训练对脑缺血大鼠脑组织Reelin、PI3KCA及突触素表达的影响

Effect of treadmill training on Reelin,PI3KCA and synaptophysin in rats with focal cerebral ischemia

目的:观察脑缺血大鼠跑台运动训练后神经功能恢复情况及磷脂酰肌醇-3-激酶α亚单位(phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha isoform,PI3KCA)、Reelin及突触素表达的变化。方法:选取健康雄性SD大鼠54只,随机分为假手术组、缺血对照组及运动训练组。采用线栓法大脑中动脉闭塞(middle cerebral artery occlusion,MCAO)方法造成局灶性脑缺血模型。运动训练组于造模后第3天进行16 d的跑台训练(15 m/min,每日30 min)。运用改良神经功能缺损评分(modified neurological severity scores,mNSS)对3组动物进行神经功能评分。采用HE染色观察各组海马神经细胞形态;运用免疫组化方法检测各组Reelin及PI3KCA阳性细胞数;Western blot检测各组缺血皮质Reelin及突触素蛋白水平。结果:MCAO术后19 d,运动训练组mNSS评分较缺血对照组明显降低(P<0.05)。HE染色显示,假手术组海马神经细胞结构完整;缺血对照组海马神经细胞出现异常变化,细胞体积缩小,核不规则,细胞排列散乱,大量变性;运动训练组海马神经细胞结构基本正常,细胞排列尚整齐。免疫组化显示,运动训练组大鼠缺血侧脑组织Reelin及PI3KCA阳性细胞数均高于缺血对照组,差异有统计学意义(18.27±4.03 vs.7.53±2.03,P<0.01;10.27±1.62 vs.5.40±1.84,P<0.01)。Western blot检测运动训练组Reelin及突触素蛋白表达明显高于缺血组和假手术组,差异有统计学意义(P<0.05);而缺血组较假手术组Reelin及突触素蛋白的表达水平虽增加,但差异无统计学意义(P>0.05)。结论:跑台运动训练可改善局灶性脑缺血大鼠神经功能评分,上调脑组织Reelin、PI3KCA及突触素的表达,促进脑缺血后的神经功能恢复。

[Abstract]Objective：To observe the changes in nerve function recovery and the expression of Reelin,PI3KCA and synaptophysin in isehemic brain tissues of cerebral ischemic rats after treadmill training. Methods ： A total of 54 rats were randomly divided into three groups：sham-operated group,ischemic control group and treadmill training group. Middle cerebral artery occlusion （MCAO） was used to create focal cerebral ischemic model in rats. Rats in E group underwent treadmill training for 16 d（ 15 m/min, 30 min/d）. Modified neurological severity scores （mNSS） was used to evaluate the neurological function of rats in three groups. HE staining was used to observe nerve cell morphology in hippocampus of rats in three groups. Immunohistochemistry was used to detect the number of Reelin- positive and PI3KCA-positive cells. Western blot was used to detect the level of Reelin and synaptophysin in ischemic cortexs of rats in three groups. Results：The mNSS of E group was lower than that of I group on the 19th d post-MCAO（P〈0.05）. The morphology of the hippocampal neurons in S group was normal, irregular and damaged in I group, while alleviated after treadmill training. Both the expression of Reelin-positive and PI3KCA-positive cells in E group were higher than that in I group（ 18.27 ± 4.03 vs. 7.53 ± 2.03, P〈0.01 ; 10.27± 1.62 vs. 5.40 ± 1.84,P〈0.01）. The expression of Reelin and synaptophysin in ischemic cortexs of rats in E group was remarkably upregulated than that in S and I group with statistical differences（P〈0.05）. The expression of Reelin and synaptophysin in ischemic cortexs of rats in I group was upregulated than that in S group without statistical differences（P〉0.05）. Conclusions： Treadmill training can improve neurological function and upregulate the expression of Reelin, PI3KCA and synaptophysin after cerebral ischemia.