目的 探讨蛋白激酶RNA样ER激酶（protein kinase RNA-like ER kinase，PERK）信号通路介导的线粒体未折叠蛋白反应（mitochondrial unfolded protein response，mtUPR）在缺氧缺血性脑损伤（hypoxic-ischemic brain injury，HIBI）中的作用。 方法 将大鼠随机分为假手术（Sham）组和5个HIBI亚组（HIBI后3、6、12、24、48 h）。用于蛋白质印迹检测PERK、转录激活因子4（activating transcription factor 4，ATF4）、热休克蛋白60（heat shock protein 60，HSP60）蛋白的时程表达。将大鼠随机分为Sham组、HIBI组、HIBI + PERK组和HIBI+载体（Vector）组，每组15只。HIBI+PERK组和HIBI+Vector组大鼠在HIBI手术前1 h，将基于腺病毒相关病毒（adeno-associated virus，AAV）的PERK过表达质粒或AAV载体注射到脑室内，用于特异性表达PERK。在HIBI后24 h进行FJC染色分析神经元变性和DHE染色、酶联免疫吸附试验分析氧化应激。将大鼠随机分为Sham组、HIBI组、HIBI+PERK激动剂（CCT020312）组，每组12只。在HIBI手术前1 h，向HIBI+CCT020312组大鼠脑室内注射CCT020312。在HIBI后3周进行开阔场地测试和莫里斯水迷宫测试。 结果 与Sham组相比，PERK、ATF4、HSP60在HIBI后3 h开始明显升高，在12 h达到高峰，然后逐渐下降，直到48 h（F=60.23、56.72、74.31，均P<0.001）。与HIBI组相比，HIBI+PERK组神经元变性的数量（100.2±3.1 vs. 582.4±15.7，P<0.001）、活性氧（reactive oxygen species，ROS）（42.4±2.9 vs. 17.7±2.1，P<0.01）、丙二醛（Malondialdehyde，MDA）（0.81±0.06 vs. 0.54±0.04，P<0.001）水平显著降低，和谷胱甘肽过氧化物酶（glutathione peroxidase，GSHPx）（112.4±3.6 vs. 177.5±6.6，P<0.05）、超氧化物歧化酶（superoxide Dismutase，SOD）活性（46.3±1.9 vs. 64.2±2.3，P<0.05）活性明显增加。与Sham组相比，HIBI组大鼠海马组织中PERK（1.00±0.03 vs. 1.66±0.08，P<0.01）、ATF4（1.00±0.04 vs. 1.53±0.06，P<0.05）、动力蛋白相关蛋白1（dynamin-related protein 1，Drp1）（1.00±0.02 vs. 1.98±0.07，P<0.01）、HSP60（1.00±0.03 vs. 1.37±0.04，P<0.05）蛋白表达均明显增加（P<0.05）。与HIBI组相比，HIBI+PERK组大鼠海马组织中PERK（1.66±0.08 vs. 2.95±0.17，P<0.01）、ATF4（1.53±0.06 vs. 3.42±0.22，P<0.01）、HSP60（1.37±0.04 vs. 2.03±0.09，P<0.05）蛋白表达均明显增加（F=46.72、30.63、20.64，P<0.001），和Drp1（1.98±0.07 vs. 1.04±0.05，P<0.05）蛋白表达明显降低（F=35.72，P<0.001）。HIBI+CCT020312组的平均逃避潜伏期和平台穿越次数均较HIBI组明显增加（F=246.84、113.62，P<0.001）。 结论 PERK减轻HIBI模型诱导的氧化应激和神经元凋亡，其机制可能涉及PERK/ATF4信号通路对mtUPR的调节。通过CCT020312给药具有神经保护作用。

Objective To examine the role of mitochondrial unfolded protein response（mtUPR） mediated by the protein kinase RNA-like ER kinase（PERK） signaling pathway in hypoxic-ischemic brain injury（HIBI）. Methods Rats were randomly divided into the sham group and five HIBI groups（3，6，12，24 and 48 h after HIBI） for Western blot analysis of PERK，activating transcription factor 4 （ATF4），and heat shock protein 60（HSP60） protein expression over time. In another experiment，rats were randomly divided into the sham group，HIBI group，HIBI+PERK group，and HIBI+Vector group，with 15 rats in each group. Rats in the HIBI+PERK group and HIBI+Vector group were given intracerebroventricular injection of adeno-associated virus（AAV）-based PERK overexpression plasmid or empty AAV vector 1 h before HIBI to induce specific PERK expression. FJC staining was performed 24 h after HIBI to analyze neuronal degeneration，and oxidative stress was examined by DHE staining and enzyme-linked immunosorbent assay. In a third experiment，rats were randomly divided into the sham group，HIBI group and HIBI+CCT020312（PERK agonist） group，with 12 rats in each group. Rats in the HIBI+CCT020312 group were given intracerebroventricular injection of CCT020312 one hour before HIBI. Open field test and Morris water maze test were performed 3 weeks after HIBI. Results Compared with the sham group，the HIBI groups showed significantly increased PERK，ATF4，and HSP60 expression at 3 h post-HIBI，which peaked at 12 h and then gradually decreased until 48 h（F=60.23，56.72，74.31，all P<0.001）. The HIBI+PERK group had significantly lower number of degenerated neurons（100.2±3.1 vs. 582.4±15.7，P<0.001），reactive oxygen species（ROS） level （42.4±2.9 vs. 17.7±2.1，P<0.01），and malondialdehyde（MDA） level（0.81±0.06 vs. 0.54±0.04，P<0.001），but significantly higher glutathione peroxidase（GSH-Px） activity （112.4±3.6 vs. 177.5±6.6，P<0.05） and superoxide dismutase （SOD） activity （46.3±1.9 vs. 64.2±2.3，P<0.05），as compared with the HIBI group. PERK（1.00±0.03 vs. 1.66±0.08，P<0.01），ATF4 （1.00±0.04 vs. 1.53±0.06，P<0.05），dynamin-related protein 1 （Drp1；1.00±0.02 vs. 1.98±0.07，P<0.01），and HSP60 （1.00±0.03 vs. 1.37±0.04，P<0.05） protein expression in the hippocampal tissue were significantly higher in the HIBI group than in the sham group. Furthermore，the HIBI+PERK group demonstrated significantly higher PERK（1.66±0.08 vs. 2.95±0.17，P<0.01），ATF4（1.53±0.06 vs. 3.42±0.22，P<0.01），and HSP60 （1.37±0.04 vs. 2.03±0.09，P<0.05） protein expression（F=46.72，30.63，20.64，P<0.001） but significantly lower Drp1（1.98±0.07 vs. 1.04±0.05，P<0.05） protein expression in the hippocampal tissue than the HIBI group（F=35.72，P<0.001）. Mean escape latency and the number of platform crossings were significantly higher in the HIBI+CCT020312 group than in the HIBI group（F=246.84，113.62，P<0.001）. Conclusion PERK attenuates oxidative stress and neuronal apoptosis induced by HIBI，possibly through the regulation of mtUPR via the PERK/ATF4 signaling pathway. CCT020312 has neuroprotective effects in HIBI.