Pharmacological Inhibition of PERK Attenuates Early Brain Injury After Subarachnoid Hemorrhage in Rats Through the Activation of Akt
Pharmacological Inhibition of PERK Attenuates Early Brain Injury After Subarachnoid Hemorrhage in Rats Through the Activation of Akt
复制标题
PERK 的药理抑制通过激活 Akt 减轻大鼠蛛网膜下腔出血后的早期脑损伤
DOI：
10.1007/s12035-016-9790-9
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发表时间：
2017-04-01
影响因子：
5.1
通讯作者：
Chen, Gao
中科院分区：
文献类型：
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作者：
Yan, Feng;Cao, Shenglong;Chen, Gao
神经细胞凋亡是蛛网膜下腔出血(SAH)所致早期脑损伤的中心病理过程。内质网(ER)应激在脑神经细胞凋亡的病理生理学中起重要作用。本研究旨在探讨内质网应激及其下游信号在SAH后早期脑损伤中的潜在作用。134只大鼠制作蛛网膜下腔出血血管内穿孔模型。侧脑室注射RNA激活的蛋白激酶样ER激酶(PERK)抑制剂GSK2606414和Akt抑制剂MK2206。蛛网膜下腔出血后72小时测量蛛网膜下腔出血分级、神经功能评分和脑含水量。Western印迹分析检测PERK及其下游信号Akt、Bcl2、Bax和裂解的caspase-3的表达。双重免疫荧光染色检测表达PERK的特定细胞类型。用末端脱氧核苷酸转移酶(TdT)介导的dUTP缺口末端标记法(TUNEL)显示神经细胞死亡。结果表明，蛛网膜下腔出血后p-PERK及其下游靶基因p-eIF_2α和ATF_4的表达增强，并在72小时达到高峰。PERK主要在神经元中表达。用GSK2606414抑制PERK可降低p-PERK、p-eIF2α和ATF4的表达。此外，GSK2606414治疗可提高SAH后72h的p-Akt水平和Bcl2/Bax比值，减少caspase-3的裂解表达和神经元死亡，从而改善SAH后72h的神经功能缺失。选择性Akt抑制剂MK2206取消了GSK2606414的有利作用。PERK是内质网应激的主要转导因子，参与SAH后神经细胞的凋亡。PERK的抑制通过Akt相关的抗细胞凋亡途径减少早期脑损伤。PERK可能成为未来治疗干预的一个有前途的靶点。
Neuronal apoptosis is a central pathological process in subarachnoid hemorrhage (SAH)-induced early brain injury. Endoplasmic reticulum (ER) stress was reported to have a vital role in the pathophysiology of neuronal apoptosis in the brain. The present study was designed to investigate the potential effects of ER stress and its downstream signals in early brain injury after SAH. One hundred thirty-four rats were subjected to an endovascular perforation model of SAH. The RNA-activated protein kinase-like ER kinase (PERK) inhibitor GSK2606414 and the Akt inhibitor MK2206 were injected intracerebroventricularly. SAH grade, neurologic scores, and brain water content were measured 72 h after subarachnoid hemorrhage. Expression of PERK and its downstream signals, Akt, Bcl-2, Bax, and cleaved caspase-3, were examined using Western blot analysis. Specific cell types that expressed PERK were detected with double immunofluorescence staining. Neuronal cell death was demonstrated with terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL). Our results showed that the expression of p-PERK and its downstream targets, p-eIF2α and ATF4, increased after SAH and peaked at 72 h after SAH. PERK was expressed mostly in neurons. The inhibition of PERK with GSK2606414 reduced p-PERK, p-eIF2α, and ATF4 expression. Furthermore, GSK2606414 treatment increased p-Akt levels and the Bcl-2/Bax ratio as well as decreased cleaved caspase-3 expression and neuronal death, thereby improving neurological deficits at 72 h after SAH. The selective Akt inhibitor MK2206 abolished the beneficial effects of GSK2606414. PERK, the major transducer of ER stress, is involved in neuronal apoptosis after SAH. The inhibition of PERK reduces early brain injury via Akt-related anti-apoptosis pathways. PERK may serve as a promising target for future therapeutic intervention.