3-硝基丙酸预处理对大鼠局灶性脑缺血Caspase-3表达和活性的影响

Inhibition of caspase-3 activation is involved in 3-nitropropionic acid induced ischemic tolerance to transient focal cerebral ischemia in rats

目的探讨小剂量线粒体毒素3-硝基丙酸(3-nitropropionic acid,3-NPA)预处理对大鼠局灶性脑缺血半暗带半胱天冬酶-3(Caspase-3)表达和活性的影响。方法大鼠腹腔注射3-NPA20mg/kg或生理盐水3d后制作局灶性脑缺血再灌注模型,采用免疫印迹技术和荧光测定法观察3-NPA预处理对缺血2h再灌注24hCaspase-3的表达和活性的影响。结果缺血2h再灌注24h3-NPA预处理组Caspase-3表达减弱(P<0.05),活性降低(P<0.05),与对照组比较差异有显著性。结论3-NPA预处理诱导脑缺血耐受与降低Caspase-3活性,进而抑制神经细胞凋亡有关。

[Objective] To investigate the involvement of caspase-3 activation in mitochondfial toxin 3-nitropropionic acid （3-NPA）-induced ischemic tolerance to transient focal cerebral ischemia in rats. [Methods] Rats were administrated either vehicle control or 3-NPA at intraperitoneal doses of 20 mg·kg^-1. Three days later, rats were exposed to 2 hours of middle cerebral artery occlusion followed by 24 hours of reperfusion. Expression of caspase-3 was assessed by Western blot 24 hours after reperfusion. Cleavage of the fluorogenic substrate DEVD-afc was used to assay caspase-3 activity. [Results] Compared to the vehicle-injected group, pretreatment with 3-NPA significantly reduced caspase-3 expression. In terms of caspase-3 activity in ischemic penumbra tissues, the 3-NPA pretreated group showed significantly less caspase-3 activity than the control group. [Conclusion] The development of 3-NPA-induced ischemic tolerance in brain may be related to decreases in caspase-3 activaity, which leads to decreased neural cell apoptosis.