通心络对脑缺血再灌注损伤后大鼠内源性神经巢蛋白和碱性成纤维生长因子表达的影响

Effect of Tongxinluo on the expression of endogenous nestin and basic fibroblast growth factor after cerebral ischemia-reperfusion injury in rats

目的探讨通心络对脑缺血再灌注损伤后大鼠内源性神经巢蛋白(Nestin)和碱性成纤维生长因子(bFGF)表达的影响。方法改良线栓法制作大鼠大脑中动脉缺血再灌注损伤模型,分为模型组、通心络大剂量组(1.0 g·kg^(-1)·d^(-1))、通心络小剂量组(0.5 g·kg^(-1)·d^(-1))和假手术组。免疫荧光法检测各组大鼠缺血再灌注损伤后第3、5、7、14、21、30天病灶侧侧脑室下区(SVZ)、海马齿状回(DG)区5-溴脱氧尿嘧啶核苷(BrdU)和Nestin的变化,逆转录聚合酶链式扩增(RT-PCR)方法检测相应时间点病灶侧碱性成纤维生长因子信使核糖核酸(bFGF mRNA)的表达。结果假手术组几乎检测不到BrdU+Nestin和bFGF mRNA的表达。通心络大剂量和小剂量组第5、7、14、21、30天病灶侧SVZ、DG区BrdU+Nestin荧光强度值与模型组比较差异均有统计学意义(P<0.05)。第5、7、14、21、30天通心络大剂量组与通心络小剂量组BrdU+Nestin荧光强度值比较有统计学意义(P<0.05)。通心络大剂量和小剂量组第5天BrdU+Nestin阳性荧光强度值增加,第14天达最高(P<0.05),并持续到缺血再灌注后第30天。缺血再灌注后各时间点通心络大剂量和小剂量组分别与模型组bFGF mRNA表达比较差异均有统计学意义(P<0.05)。通心络大剂量和小剂量组bFGF mRNA表达在缺血再灌注后第3天开始增高,第7天表达值最高(P<0.05),并持续到第30天仍然有较高水平,而模型组第30天已恢复到基线水平。模型组、通心络大剂量组和通心络小剂量组组内不同时间BrdU+Nestin荧光强度值和bFGFmRNA表达比较差异均有统计学意义(P<0.05)。结论大鼠脑缺血再灌注损伤可引起病灶侧SVZ、DG区神经干细胞反应和增殖;通心络可显著增加大脑中动脉缺血及再灌注模型大鼠神经干细胞的增殖分化能力。通心络促使病灶侧bFGFmRNA表达上调可能为促进神经干细胞增殖分化的机制之一。

Objective To investigate the effect of Tongxinluo on the expression of endogenous nestin and basic fibroblast growth factor（bFGF） after cerebral ischemia-reperfusion injury in rats.Methods Ischemia was induced by temporary middle cerebral artery occlusion（MCAO）,which was divided into model group,high dose group of Tongxinluo（1g·kg^（-1）·d^（-1））,low dose group of Tongxinluo（0.5 g·kg^（-1）·d^（-1）） and the sham operation group.The number of 5-Br deoxy uridine monophosphate （BrdU） and nestin in subventricle zone（SVZ） and dentate gyrus（DG） of rats at 3,5,7,14,21 and 30 days after MCAO were detected by immunohistochemistry and the bFGF mRNA were detected by RT-PCR at the same time.Results Almost there weren＇t BrdU＋Nestin and bFGF mRNA expression in the sham operation group.Compared with model group,the immunofluorescin intensity of BrdU＋Nestin increased at 5th day after MCAO in Tongxinluo high dose group and low dose group and achieved highest level at 14th day（P0.05）.The bFGF mRNA expression in Tongxinluo high dose group and low dose group were significantly higher than that in model group at each time point（P0.05）,and the higher level last to 30th day.The BrdU＋Nestin in SVZ and DG of Tongxinluo high dose group was significantly higher than those in Tongxinluo low dose group at 5th,7th,14th,21 st and 30th day after MCAO（P0.05）.The bFGF mRNA expression in Tonglxinluo high dose group and low dose group had significant diference compared with model group at the each time point（P0.05）,but there was no statistic diference between Tongxinluo high dose group and low dose group（P0.05）.Conclusions Cerebral ischemia-reperfusion injury can cause response and proliferation of neural stem cells in SVZ and DG of rats;Tongxinluo can enhance the ability of the differentiation and proliferation of neural stem cell in MCAO rats.Tongxinluo promote the expression of bFGF mRNA may be one of the mechanisms which promote the proliferation and differentiation of neural stem cells.