黄芩苷通过调节Fas/FasL信号通路减轻小鼠癫痫持续状态神经细胞凋亡的机制

Mechanism of baicalin alleviated neuronal apoptosis after status epilepticus in mice by regulating Fas/FasL signaling pathway

目的探讨黄芩苷通过调节Fas/FasL信号通路减轻小鼠癫痫持续状态(SE)神经细胞凋亡的机制。方法45只雄性ICR小鼠按随机数字表法分为三组:对照组、SE组、黄芩苷治疗组。采用腹腔注射海人酸建立小鼠癫痫模型,对照组注入等量的生理盐水,黄芩苷治疗组腹腔注射100 mg/kg的黄芩苷。通过原位末端标记法(TUNEL)染色观察小鼠海马CA1区神经细胞的凋亡;免疫组化观察海马组织中Fas、FasL的表达与分布;逆转录-聚合酶链反应(RT-PCR)检测海马组织中天冬氨酸特异性半胱氨酸蛋白酶(caspase)-3、caspase-8 mRNA的含量;免疫印迹试验检测Fas、FasL和caspase-8蛋白的表达量。结果黄芩苷治疗组海马CA1区神经细胞的凋亡数明显低于SE组,差异有统计学意义(P<0.05);同时,黄芩苷治疗组海马中caspase-3、caspase-8mRNA和Fas、FasL、caspase-8蛋白的含量均低于SE组,差异有统计学意义(P<0.05)。结论黄芩苷能够减轻小鼠癫痫发作后海马神经细胞的凋亡,其机制可能与抑制Fas/FasL信号通路及降低其下游的caspase-8、caspase-3的表达有关。

Objective To explore the mechanism of baicalin alleviated neuronal apoptosis after status epilepticus(SE)in mice by regulating Fas/FasL signaling pathway.Methods A total of 45 ICR mice were divided into 3 groups:control group,SE group,and baicalin treatment group according to random number table mothod.The epilepsy model of mice was established by intraperitoneal injection of kainic acid,the control group was injected with the same amount of normal saline,and the baicalin treatment group was intraperitoneally injected with 100 mg/kg of baicalin.TdT-mediated dUTP nick end labeling(TUNEL)staining was used to observe the apoptosis of neurons in the CA1 region of the mouse hippocampus;immunohistochemistry was used to observe the expression and distribution of Fas and FasL;reverse transcription PCR(RT-PCR)was used to detect the contents of cysteine-containing aspartate-specific proteases(caspase)-3 and caspase-8 mRNA;western blot was used to detect the expression of protein level of Fas,FasL and caspase-8 proteins.Results The number of apoptosis of nerve cells in hippocampal CA1 region in baicalin treatment group was lower than that in SE group,and the difference was statistically significant(P<0.05).Meanwhile,mRNA and protein contents of caspase-3,caspase-8,Fas,FasL and caspase-8 in hippocampus of baicalin treatment group were lower than those of SE group,with statistical significances(P<0.05).Conclusion Baicalin can reduce the apoptosis of hippocampal nerve cells after epileptic seizure in mice,and the mechanism may be related to the inhibition of Fas/FasL signaling pathway and the down-regulation of caspase-8 and caspase-3.