依达拉奉对大鼠XRCC1和细胞凋亡的影响

Effect of edaravone on XRCC1 expression and apoptosis in rats

目的研究大鼠全脑缺血/再灌注不同时点海马CA1区神经元细胞凋亡与DNA修复蛋白XRCC1的变化及相互关系,探讨依达拉奉对神经元细胞凋亡与DNA修复蛋白表达的影响。方法 SD大鼠108只,随机平均分为假手术组(SH组)、缺血再灌注组(IR组)和依达拉奉干预组(ED组)。采用四血管阻塞法建立大鼠全脑缺血再灌注模型,干预组经腹腔注射依达拉奉。分别于再灌注后2、6、12、24、48、72 h处死大鼠,提取脑海马部组织。原位末端标记法(TUNEL)检测细胞凋亡;免疫组织化学方法检测DNA修复蛋白XRCC1的表达。结果 TUNEL法:SH组凋亡率较低,IR组凋亡率于缺血再灌注6 h开始明显增多,48 h凋亡率达到最高。IR组与SH组凋亡率比较,差异有统计学意义(P<0.01)。ED组在6 h后各时点凋亡率较IR组降低(P<0.01)。免疫组化方法:SH组XRCC1在各时点表达较为明显;IR组XRCC1表达在缺血再灌注2 h开始下降,6 h后下降明显,持续到72 h,与SH组比较差异有统计学意义(P<0.01);ED组XRCC1表达量降低不明显,各时点与IR组比较差异有统计学意义(P<0.01)。结论依达拉奉通过减缓XRCC1表达的下降,促进DNA损伤修复,从而阻止锥体细胞凋亡,进而起到脑保护作用。

Objective To study the apoptosis of neuron in CA1 region of hippocampus and the changes of DNA repair proteins XRCC1 as well as the relations between these changes and apoptosis at different time points after global cerebral ischemia reperfusion in rats. To explore the effects of edaravone exert on the apoptosis of neuron and on the expression of DNA repair proteins. Methods 108 male SD rats were randomized into sham operation group（ SH group） , ischemia/reperfusion group （ IR group ） and tea polyphenols intervening group （ ED group ） randomly. The CIR model was established according to the 4-VO method, and ED group was injected with edaravone. To execute rats and obtain the hippocampus tissue at 2,6,12,24,48, and 72 h after CIR respectively. Observing the apoptosis through TUNEL and the expression of XRCCI proteins through immunohistochemistry respectively. Results TUNEL：There were fewer apoptotic pyramial cells in SH group; but in IR group, the apoptosis rate increased obviously at 6 h after CIR, reaching the highest at 48 h, compared with SH group, there was significant difference （P 〈 0. 01 ）. The apoptosis rate of ED group was lower than that of IR group at different time points except at 2 h（P 〈0. 01 ）. IHC：XRCC1 in SH group expressed very apparently at different time points;however,the expression of XRCC1 in IR group started to de- crease at 2 h after CIR, at 6 h decreased obviously,it lasted until 72 h, compared with SH group, there was significant difference（ P 〈0. 01 ） ;The decrease of XRCC1 expression in ED group was not obvious. There were significant differ- ences between ED group and IR group at different time points （ P 〈 0. 01 ）. Conclusion By slowing the decrease of XRCC1 expression,edaravone can promote the repair of DNA damages and decrease the apoptosis in CA1 region in hippocampus of rats with cerebral ischemia reperfusion, then edaravone can protect the cerebrum after cerebral ischemia reperfusion injury.