Inhibition of thioredoxin-1 with siRNA exacerbates apoptosis by activating the ASK1-JNK/p38 pathway in brain of a stroke model rats
Inhibition of thioredoxin-1 with siRNA exacerbates apoptosis by activating the ASK1-JNK/p38 pathway in brain of a stroke model rats
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DOI：
10.1016/j.brainres.2014.12.033
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发表时间：
2015-03-02
期刊：
影响因子：
2.9
通讯作者：
Zhao, Jing
中科院分区：
文献类型：
--
作者：
Wu, Xiaoying;Li, Lingyu;Zhao, Jing
细胞凋亡对于脑缺血/再灌注损伤的发生至关重要。硫氧还蛋白-1（Trx-1）蛋白已被报道在多种细胞类型中具有抗凋亡作用，并且它已被牵连在大脑中动脉闭塞（MCAO）后的脑损伤中。因此，我们研究了大鼠MCAO后Trx 1沉默的影响，并研究了内源性Trx 1的抑制是否会增加组织细胞凋亡水平。雄性Sprague-Dawley大鼠（N=170）进行1小时的大脑中动脉闭塞，然后再灌注24小时。在MCAO前24 h将Trx 1 siRNA注射到大鼠脑中。然后，在MCAO后24小时，从安乐死的大鼠中收集脑用于研究。Trx 1 siRNA治疗显着增加了MCAO损伤后的死亡率、行为缺陷和脑梗死体积，并加剧了神经元细胞凋亡死亡。Western blot显示Trx 1 siRNA处理组中凋亡蛋白如P-ASK 1、P-JNK、P-p38、切割的caspase-3的表达增加，细胞色素c的水平增加。免疫共沉淀实验表明正常大鼠脑内Trx 1与ASK 1之间存在相互作用，Trx 1 siRNA可解离ASK 1-Trx 1结合复合物。我们的数据表明，Trx 1 siRNA增加凋亡应激诱导的ASK 1激活，这代表了进一步的证据，Trx 1是一种内源性抗凋亡分子，减少局灶性脑缺血/再灌注损伤。其作用机制可能与ASK 1-JNK/p38信号通路的减弱有关。(C)2014爱思唯尔有限公司版权所有。
Apoptosis is critical for the development of cerebral ischemia/reperfusion injury. Thioredoxin-1(Trx-1) protein has been reported to have anti-apoptotic effects in a variety of cell types, and it has been implicated in brain injury after middle cerebral artery occlusion (MCAO). Thus, we studied the effects of Trx1 silencing after MCAO in rats and examined whether inhibition of endogenous Trx1 could increase tissue levels of apoptosis. Male Sprague-Dawley rats (N=170) were subjected to 1 h of middle cerebral arterial occlusion followed by 24 h of reperfusion. Trx1 siRNAs were injected into rat brains 24 h prior to MCAO. Then, 24 h after MCAO, brains were collected from euthanized rats for investigation. Treatment with Trx1 siRNA significantly increased mortality, behavioral deficits, and cerebral infarction volume and exacerbated neuronal cell apoptotic death after MCAO injury. Western blot revealed increased expression of apoptotic proteins such as P-ASK1, P-JNK, P-p38, cleaved caspase-3 and increased the level of cytochrome c in the cytosolic fraction in the Trx1 siRNA-treated group. Co-immunoprecipitation assay suggested an interaction between Trx1 and ASK1 in normal rat brains and Trx1 siRNA dissociated ASK1-Trx1 binding complex. Our data suggest that Trx1 siRNA increases apoptotic stress-induced ASK1 activation and this represents further evidence that Trx1 is an endogenous anti-apoptotic molecule that diminishes focal cerebral ischemia/reperfusion injury. Its mechanism of action is likely related to attenuation of the ASK1-JNK/p38 signaling pathway. (C) 2014 Elsevier B.V. All rights reserved.