Superoxide during reperfusion contributes to caspase-8 expression and apoptosis after transient focal stroke
Superoxide during reperfusion contributes to caspase-8 expression and apoptosis after transient focal stroke
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DOI：
10.1161/hs1001.097241
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发表时间：
2001-10-01
期刊：
影响因子：
8.3
通讯作者：
Chan, PH
中科院分区：
文献类型：
--
作者：
Morita-Fujimura, Y;Fujimura, M;Chan, PH
背景和目的-再灌注过程中产生的活性氧可能在局灶性脑缺血（FCI）中起有害作用。我们研究了caspase-8的蛋白表达，它在FCI有或无再灌注后的Fas依赖性和细胞色素c依赖性凋亡途径中起着重要作用。Caspase-8表达短暂的FCI后进行了比较野生型和转基因小鼠，过表达的胞质抗氧化剂铜/锌超氧化物歧化酶（SOD 1）。方法成年雄性CD-1小鼠进行1小时的FCI和再灌注或永久性FCI的大脑中动脉的腔内封锁。通过基因组DNA凝胶电泳评估DNA片段化。Caspase-8的表达通过Western blot分析。结果-Caspase-8在短暂性FCI后4小时显著诱导，并保持在增加的水平，直到24小时，而永久性FCI后，它没有被修改。基因组DNA凝胶电泳显示DNA梯状化的模式类似于细胞凋亡中看到的模式，在短暂FCI后24小时有少量的背景涂片，而25小时的永久FCI导致较少的DNA梯状化，具有较强的背景涂片。Caspase-8的诱导显着减少SOD 1转基因小鼠与野生型小鼠4小时后短暂FCI. Conclusions结果表明，在再灌注过程中增加活性氧的产生可能有助于Caspase-8的诱导，从而加剧FCI后的细胞凋亡。
Background and Purpose-Reactive oxygen species produced during reperfusion may play a detrimental role in focal cerebral ischemia (FCI). We examined the protein expression of caspase-8, which plays a major role in both Fas-dependent and cytochrome c-dependent apoptotic pathways after FCI with or without reperfusion. Caspase-8 expression after transient FCI was compared between wild-type and transgenic mice that overexpress the cytosolic antioxidant copper/zinc superoxide dismutase (SOD1).Methods-Adult male CD-1 mice were subjected to I hour of FCI and reperfusion or to permanent FCI by intraluminal blockade of the middle cerebral artery. DNA fragmentation was evaluated by genomic DNA gel electrophoresis. Caspase-8 expression was analyzed by Western blot.Results-Caspase-8 was significantly induced 4 hours after transient FCI and remained at an increased level until 24 hours, whereas it was not modified after permanent FCI. Genomic DNA gel electrophoresis showed DNA laddering in a pattern similar to that seen in apoptosis, with a small amount of background smear 24 hours after transient FCI, whereas 25 hours of permanent FCI resulted in less DNA laddering with a strong background smear. Caspase-8 induction was significantly reduced in SOD1 transgenic mice compared with wild-type mice 4 hours after transient FCI.Conclusions-The results suggest that increased reactive oxygen species production during reperfusion may contribute to the induction of caspase-8, thereby exacerbating apoptosis after FCI.