双苯氟嗪抗大鼠全脑缺血再灌注所致海马CA1区神经元损伤的作用机制(英文)

Mechanism of anti-apoptotic action of dipfluzine on neuronal damage of the rat hippocampal CA1 region subjected to transient forebrain ischemia

目的 研究双苯氟嗪抗大鼠全脑缺血再灌注损伤的作用机制。方法 大鼠全脑缺血 15min再灌注 3d,再灌注开始后给予双苯氟嗪 ( 20, 40和 80mg·kg-1,ig)。免疫组织化学方法观察Fas及Fas配体的分子定位,Westernblotting和RT PCR方法检测Fas,Fas配体,caspase10p20,caspase8,I κB α和p I κB α蛋白及mRNA表达。结果 双苯氟嗪明显降低海马CA1区免疫阳性细胞数量及Fas,Fas配体,caspase10p20蛋白表达 (P<0 01),且呈剂量依赖性(20和 40mg·kg-1组,r=0 92,P<0 01);显著降低Fas及Fas配体mRNA表达(P<0 01);caspase8和I κB α蛋白表达在给药前后无显著变化 (P>0 05 );未能检测出p I κB α蛋白表达。结论 双苯氟嗪通过抑制CD95分子启动的死亡信号转导通路发挥其抗脑缺血再灌注损伤作用;这一作用与转录因子NF κB无关。

Aim To explore the relations between anti-apoptotic role of dipfluzine (DIP) and the death signaling transduction pathway initiated by CD95 molecules, and the transcription factor involved in the transcription regulation of CD95 molecules in the hippocampal CA1 region after transient forebrain ischemia. Methods The rat forebrain transient ischemia model was established through 15 min ischemia followed by 3 days reperfusion by using the four-vessel method. The rats were divided randomly into five groups: sham control group, ischemia / reperfusion (I/R) group, DIP treated groups (20, 40 and 80 mg·kg-1 body weight, ig, separately). Western blotting and RT-PCR were performed to detect the expression changes of Fas, FasL, caspase 10 p20, caspase 8, I-κB-α, and p-I-κB-α molecules in protein and mRNA levels, separately, and immunohistochemistry for molecular localization of Fas and FasL in rat hippocampus. Results The expression of Fas, FasL, and caspase 10 p20 in protein and mRNA levels increased after I/R, which was inhibited significantly after treatment with 20 and 40 mg·kg-1 of DIP (P<0.01). In 80 mg·kg-1 of DIP group, the expression of Fas and FasL protein was not significantly different from that of I/R group (P>0.05). The expression of caspase 8 and I-κB-α showed no significant differences in all groups (P>0.05), and no gene expression was observed for p-I-κB-α protein in the study. DIP significantly affected molecular distribution of Fas and FasL protein in CA1 subregion of hippocampus. Conclusion DIP inhibits the death signaling transduction pathway initiated by CD95 molecules in rat hippocampal CA1 subregion, and NF-κB transcription factor may not be involved in the transcription regulation of CD95 molecules after transient forebrain ischemia.