RIP3 induces ischemic neuronal DNA degradation and programmed necrosis in rat via AIF.
RIP3 induces ischemic neuronal DNA degradation and programmed necrosis in rat via AIF.
复制标题
RIP3通过AIF诱导大鼠缺血性神经元DNA降解和程序性坏死
DOI：
10.1038/srep29362
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发表时间：
2016-07-05
影响因子：
4.6
通讯作者：
Luo B
中科院分区：
文献类型：
--
作者：
Xu Y;Wang J;Song X;Qu L;Wei R;He F;Wang K;Luo B
我们报道了受体相互作用蛋白3（RIP 3）核转位参与20分钟全脑缺血/再灌注（I/R）损伤后神经元程序性坏死。本文对RIP 3的作用机制及在细胞核中的作用进行了进一步的研究。缺血前1 h侧脑室给予坏死性凋亡抑制剂necrostatin-1（Nec-1）、自噬抑制剂3-甲基腺嘌呤（3-MA）和半胱天冬酶-3抑制剂乙酰基-L-乙酰基-L-甲硫氨酰-L-乙酰氨基-L-门冬氨酸-1-醛（Ac-DMQD-CHO）。蛋白质的表达，定位和相互作用，确定了蛋白质印迹，免疫荧光或免疫沉淀。20分钟全脑I/R损伤诱导的大多数CA 1神经元死亡为TUNEL阳性。Nec-1和3-MA预处理可显著抑制神经元死亡和大鼠死亡率，但Ac-DMQD-CHO不能抑制。缺血再灌注损伤后caspase-3无激活。Caspase-8在胶质纤维酸性蛋白阳性的星形胶质细胞和Iba-1阳性的小胶质细胞中表达丰富，而在Neun阳性的神经元中不表达。在I/R损伤后检测RIP 3和AIF的核转位、共定位及其相互作用。这些过程被Nec-1和3-MA预处理抑制，但不被Ac-DMQD-CHO抑制。RIP 3-AIF复合物的形成及其核转位对缺血性神经元DNA降解和程序性坏死至关重要。由于caspase-8抑制的丧失，神经元更可能进入程序性坏死信号通路。
We have reported that nuclear translocation of Receptor-interacting protein 3 (RIP3) involves in neuronal programmed necrosis after 20-min global cerebral ischemia/reperfusion (I/R) injury. Herein, the underlying mechanisms and the nuclear role of RIP3 were investigated further. The necroptosis inhibitor necrostatin-1 (Nec-1), the autophagy inhibitor 3-methyladenine (3-MA) and the caspase-3 inhibitor acetyl-L-aspartyl-L-methionyl-L-glutaminyl-L-aspart-1-al (Ac-DMQD-CHO) were administered intracerebroventricularly 1 h before ischemia. Protein expression, location and interaction was determined by western blot, immunofluorescence or immunoprecipitation. Most CA1 neuronal death induced by 20-min global cerebral I/R injury was TUNEL-positive. Neuronal death and rat mortality rates were greatly inhibited by Nec-1 and 3-MA pre-treatment, but not by Ac-DMQD-CHO. And no activation of caspase-3 was detected after I/R injury. Caspase-8 was expressed richly in GFAP-positive astrocytes and Iba-1-positive microglia, but was not detected in Neun-positive neurons. The nuclear translocation and co-localization of RIP3 and AIF and their interaction were detected after I/R injury. These processes were inhibited by Nec-1 and 3-MA pre-treatment, but not by Ac-DMQD-CHO. The formation of an RIP3-AIF complex and its nuclear translocation are critical to ischemic neuronal DNA degradation and programmed necrosis. Neurons are more likely to enter the programmed necrosis signal pathway for the loss of caspase-8 suppression.