Inhibition of Necroptosis Rescues SAH-Induced Synaptic Impairments in Hippocampus via CREB-BDNF Pathway
Inhibition of Necroptosis Rescues SAH-Induced Synaptic Impairments in Hippocampus via CREB-BDNF Pathway
复制标题
抑制坏死性凋亡可通过 CREB-BDNF 通路挽救 SAH 引起的海马突触损伤
DOI：
10.3389/fnins.2018.00990
复制
发表时间：
2019-01-07
影响因子：
4.3
通讯作者：
Li, Gang
中科院分区：
文献类型：
--
作者：
Yang, Chunlei;Li, Tong;Li, Gang
蛛网膜下腔出血（SAH）是一种毁灭性的中风形式，导致无法治愈的结果。越来越多的证据表明，早期脑损伤（EBI）是导致SAH预后不良的主要原因。一个以前未知的机制，调节细胞死亡称为坏死性凋亡最近有报道。Necrostatin-1（nec-1）是一种特异性的、有效的坏死性凋亡抑制剂，可减轻SAH后的脑损伤。然而，nec-1对海马的作用及其对SAH后突触的神经保护作用尚不清楚。本研究旨在探讨nec-1对SAH后EBI突触及其相关信号通路的影响。在SAH后大鼠模型中通过侧脑室注射给予Nec-1。SAH后24 h进行神经行为学评分和脑水肿检测。受体相互作用蛋白1和3（RIP 1和3）的表达作为坏死性凋亡的标志物进行了检查。采用苏木精-伊红染色、尼氏染色、银染和末端脱氧核苷酸转移酶缺口末端标记法（TUNEL）观察海马的形态学变化。采用Western blotting和电镜观察nec-1对突触的保护作用，Western blotting检测cAMP反应元件结合（CREB）蛋白和脑源性神经营养因子（BDNF）的表达，透射电镜和TUNEL法检测CREB特异性抑制剂666-15对nec-1的保护作用。我们的结果显示，在SAH组，RIP 1和RIP 3在海马中显著增加。此外，与SAH组相比，注射nec-1减轻了脑水肿，改善了神经行为评分。Sham+nec-1组神经元损伤减轻，突触结构改善。此外，nec-1治疗显著提高磷酸化CREB和BDNF的水平相比，在SAH组。nec-1的保护作用可被666-15阻断。因此，nec-1通过抑制与CREB-BDNF通路相关的坏死性凋亡减轻了SAH诱导的海马突触损伤。本研究可能为SAH患者的临床治疗提供一种新的策略。
Subarachnoid hemorrhage (SAH) is a devastating form of stroke that leads to incurable outcomes. Increasing evidence has proved that early brain injury (EBI) contributes mostly to unfavorable outcomes after SAH. A previously unknown mechanism of regulated cell death known as necroptosis has recently been reported. Necrostatin-1 (nec-1), a specific and potent inhibitor of necroptosis, can attenuate brain impairments after SAH. However, the effect of nec-1 on the hippocampus and its neuroprotective impact on synapses after SAH is not well understood. Our present study was designed to investigate the potential effects of nec-1 administration on synapses and its relevant signal pathway in EBI after SAH. Nec-1 was administrated in a rat model via intracere-broventricular injection after SAH. Neurobehavior scores and brain edema were detected at 24 h after SAH occurred. The expression of the receptor-interacting proteins 1 and 3 (RIP1and3) was examined as a marker of necroptosis. We used hematoxylin and eosin staining, Nissl staining, silver staining and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) to observe the morphological changes in hippocampus. The protective effect of nec-1 on synapses was evaluated using western blotting and electron microscopy and Western blotting was used to detect the cAMP responsive element binding (CREB) protein and brain-derived neurotrophic factor (BDNF), and we used transmission electron microscopy and TUNEL to detect the protective effects of nec-1 when a specific inhibitor of CREB, known as 666-15, was used. Our results showed that in the SAH group, RIP1, and RIP3 significantly increased in the hippocampus. Additionally, injection of nec-1 alleviated brain edema and improved neurobehavior scores, compared with those in the SAH group. The damage to neurons was attenuated, and synaptic structure also improved in the Sham+nec-1 group. Furthermore, nec-1 treatment significantly enhanced the levels of phospho-CREB and BDNF compared with those in the SAH group. The protective effect of nec-1 could hindered by 666-15. Thus, nec-1 mitigated SAH-induced synaptic impairments in the hippocampus through the inhibition of necroptosis in connection with the CREB-BDNF pathway. This study may provide a new strategy for SAH patients in clinical practice.