运动预处理对脑缺血再灌注大鼠VEGF、NeuN蛋白表达的影响

目的:探索运动预处理对于脑缺血再灌注大鼠血管内皮生长因子(VEGF)、神经元核心抗原(NeuN)蛋白表达的影响。方法:采用随机数字表法将大鼠分为假手术组、模型组、运假组(运动预处理与假手术组)和运模组(运动预处理与模型组),每组24只。每组按再灌注24 h、3 d后又分为2个亚组,每个亚组12只。造模前,运假组和运模组行跑台训练3周。模型组和运模组大鼠采用改良Longa线栓法制备大鼠大脑中动脉阻塞(MCAO)模型,造模2 h后将线栓缓慢拔出至颈总动脉主干分叉处。假手术组和运假组大鼠造模方法同上,但线栓仅从颈总动脉插入约10 mm以后即拔出,不能阻塞大脑中动脉血流供应。采用改良神经功能评分(mNSS)评估神经功能;免疫组化和蛋白质免疫印迹分别测定缺血侧脑组织VEGF和NeuN蛋白表达水平。结果:①假手术组和运假组未出现神经功能缺损表现,与模型组比较,运模组在再灌注24 h、3 d后神经功能缺损评分降低,组间比较差异有统计学意义(P<0.05)。②在VEGF表达方面,再灌注24 h后,假手术组可见少量的VEGF表达,阳性细胞胞体小,突起细;与运模组阳性率(14.40%)相比,假手术组阳性率(4.70%)、模型组阳性率(9.80%)、运假组阳性率(8.80%)均较低,且差异均有统计学意义(P<0.05)。再灌注3 d后,与运模组阳性率(23.80%)相比,假手术组阳性率(5.40%)、模型组阳性率(12.40%)、运假组阳性率(14.20%)均降低,且差异均有统计学意义(P<0.05)。③在NeuN蛋白表达水平方面,再灌注24 h后,与运模组相比,模型组表达较少,差异有统计学意义(P<0.05);再灌注3 d后,与运模组相比,模型组表达较少,差异有统计学意义(P<0.05)。结论:脑缺血再灌注前给予运动预处理可减少脑缺血再灌注以后的神经功能缺损表现,通过增强VEGF与NeuN的蛋白表达,从而改善感觉运动功能障碍和运动行为。

Effect of Exercise Preconditioning on Protein Expression of VEGF and NeuN in Rats with Cerebral Ischemia-reperfusion

Objective:To explore the effects of exercise preconditioning on the expression of vascular endothelial growth factor(VEGF)and neuronal core antigen(NeuN)proteins in rats with cerebral ischemia-reperfusion.Methods:The rats were randomly divided into sham-operation group,model group,exercise sham-operation group(exercise pretreatment and sham-operation group)and exercise model group(exercise pretreatment and model group)by the random number table method,with 24 rats in each group.Each group was then divided into two subgroups according to the cerebral ischemia-reperfusion time of 24 hours and 3 days,with 12 rats in each subgroup.Before the model was built,the exercise sham-operation group and the exercise model group were trained on the treadmill for 3 weeks.In the model group and exercise model group,the modified Longa suture method was used to prepare the rat middle cerebral artery occlusion(MCAO)model.After 2 hours,the suture was slowly pulled out to the branch of the common carotid artery.The method of modeling rats in the sham-operation group and the exercise sham-operation group was the same as the above,but the thread plug was only inserted about 10 mm from the common carotid artery and then pulled out,which could not block the middle cerebral artery blood supply.The modified neurologic severity score(mNSS)was used to assess neurological function,while the immunohistochemistry and Western blot were respectively used to determine the protein expression levels of VEGF and NeuN in the ischemic lateral brain tissue.Results:1)There were no neurological deficits in the sham-operation group and the exercise sham-operation group.Compared with the model group,the neurological deficit scores of the exercise model group at 24 hours and 3 days after cerebral ischemia-reperfusion decreased,and the comparison between the two groups was statistically significant(P<0.05).2)24 hours after cerebral ischemia-reperfusion,a small amount of VEGF expression were seen in the sham operation group,the positive cell bodies were small,and the protrusions were thin;compared with the positive rate of the exercise model group(14.40%),the positive rate of the sham-operation group(4.70%),the positive rate of the model group(9.80%),the positive rate of the exercise sham-operation group(8.80%)were low,and the differences were statistically significant respectively(P<0.05).Three days after cerebral ischemia-reperfusion,compared with the positive rate of the exercise model group(23.80%),the positive rate of the sham-operation group(5.40%),the positive rate of the model group(12.40%),and the positive rate of the exercise sham-operation group(14.20%)were all reduced,and the differences were statistically significant respectively(P<0.05).3)24 hours after cerebral ischemia-reperfusion,compared with the exercise model group,the expression of NeuN protein in the model group was less,and the difference was statistically significant(P<0.05);Three days after cerebral ischemia-reperfusion,compared with the exercise model group,the expression of the model group was less,and the difference was statistically significant(P<0.05).Conclusion:Exercise preconditioning before cerebral ischemia-reperfusion can reduce the performance of neurological deficits after cerebral ischemia-reperfusion,and improve sensorimotor dysfunction and motor behavior by enhancing the protein expression of VEGF and NeuN.