Arc silence aggravates traumatic neuronal injury via mGluR1-mediated ER stress and necroptosis
Arc silence aggravates traumatic neuronal injury via mGluR1-mediated ER stress and necroptosis
复制标题
电弧沉默通过 mGluR1 介导的 ER 应激和坏死性凋亡加重创伤性神经元损伤。
DOI：
10.1038/s41419-019-2198-5
复制
发表时间：
2020-01-02
影响因子：
9
通讯作者：
Hang, Chun-Hua
中科院分区：
文献类型：
--
作者：
Chen, Tao;Zhu, Jie;Hang, Chun-Hua
迟发性神经元死亡与创伤性脑损伤(TBI)后的神经功能障碍和死亡率有关，突触后密度(PSD)蛋白被认为在其中起关键作用。即刻早期基因(IEG)编码蛋白Arc是一种大脑特有的PSD蛋白，控制突触的可塑性和学习行为。在本研究中，我们通过模拟大脑皮层神经元创伤性神经元损伤的体外模型，研究了Arc在脑创伤后神经元死亡中的表达及其生物学功能。小干扰RNA(Si-Arc-3)抑制Arc的表达可促进TnI诱导的细胞毒作用和细胞凋亡。Western印迹结果显示，在TnI后，Si-Arc-3基因的表达进一步增强了内质网应激相关因子的激活，包括葡萄糖调节蛋白78(GRP78)、C/EBP同源蛋白(CHOP)和caspase-12。此外，下调Arc可显著增加受体相互作用蛋白激酶1(RIP1)的表达和坏死层细胞的数量，这一作用可被NEC-1明显阻止。免疫染色和免疫印迹结果显示，Arc基因敲除后，神经元的代谢性谷氨酸受体1(MGluR1)和细胞内钙离子释放均被激活。从机制上讲，mGluR1拮抗剂AIDA部分逆转了Si-Arc-3诱导的ER应激相关因子的激活、RIP1的表达、细胞凋亡和坏死性下垂。综上所述，我们的数据表明，Arc表达的沉默通过促进细胞凋亡和坏死性下垂而加重了TNI后神经元的死亡。这些数据首次支持Arc可能代表一种治疗脑外伤的新候选药物。
Delayed neuronal death is associated with neurological deficits and mortality after traumatic brain injury (TBI), where post-synaptic density (PSD) proteins are thought to play key roles. The immediate-early gene (IEG) coded protein Arc is a brain-specific PSD protein that controls synaptic plasticity and learning behaviors. In this study, we investigated the expression and biological function of Arc in neuronal death after TBI in an in vitro model mimicked by traumatic neuronal injury (TNI) in cortical neurons. TNI caused a temporal increase of Arc expression at 3 and 6 h. Knockdown of Arc expression using small interfering RNA (Si-Arc-3) promoted TNI-induced cytotoxicity and apoptosis. The results of western blot showed that Si-Arc-3 transfection further enhanced the activation of endoplasmic reticulum (ER) stress-associated factors, including glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP) and caspase-12 after TNI. In addition, knockdown of Arc significantly increased expression of (receptor-interacting protein kinase 1) RIP1 and the number of necroptotic cells, which were apparently prevented by necrostatin-1 (Nec-1). The results of immunostaining and western blot showed that knockdown of Arc activated the metabotropic glutamate receptor 1 (mGluR1) and intracellular Ca2+ release in neurons. Mechanistically, the Si-Arc-3-induced activation of ER stress-associated factors, RIP1 expression, apoptosis, and necroptosis were partially reversed by the mGluR1 antagonist AIDA. In summary, our data suggest that silence of Arc expression aggravates neuronal death after TNI by promoting apoptosis and necroptosis. These data support for the first time that Arc may represent a novel candidate for therapies against TBI.