Han Zi-Wei, Zhu Li-Cang, Chang Yue-Chen, Zhou Ying, Zong Jia-An, Ma Ke-Tao, Si Jun-Qiang, Li Li
Department of Physiology, Shihezi University Medical College/Xinjiang Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Shihezi 832002, China.
Sheng Li Xue Bao. 2019 Aug 25;71(4):527-536.
The aim of this study was to investigate whether G protein-coupled estrogen receptor (GPER) could alleviate hippocampal neuron injury under cerebral ischemia-reperfusion injury (CIRI) by acting on endoplasmic reticulum stress (ERS). The CIRI animal model was established by middle cerebral artery occlusion (MCAO). Female ovariectomized (OVX) Sprague-Dawley (SD) female rats were randomly divided into 4 groups: control, ischemia-reperfusion injury (MCAO), vehicle (MCAO+DMSO), and GPER-specific agonist G1 (MCAO+G1) groups. The neurobehavioral score was assessed by the Longa score method, the morphological changes of the neurons were observed by the Nissl staining, the cerebral infarction was detected by the TTC staining, and the neural apoptosis in the hippocampal CA1 region was detected by TUNEL staining. The distribution and expression of GRP78 (78 kDa glucose-regulated protein 78) in the hippocampal CA1 region were observed by immunofluorescent staining. The protein expression levels of GRP78, Caspase-12, CHOP and Caspase-3 were detected by Western blot, and the mRNA expression levels of GRP78, Caspase-12, and CHOP were detected by the real-time PCR. The results showed that the neurobehavioral score, cerebral infarct volume, cellular apoptosis index, as well as GRP78, Caspase-12 and CHOP protein and mRNA expression levels in the MCAO group were significantly higher than those of control group. And G1 reversed the above-mentioned changes in the MCAO+G1 group. These results suggest that the activation of GPER can decrease the apoptosis of hippocampal neurons and relieve CIRI, and its mechanism may involve the inhibition of ERS.
本研究旨在探讨G蛋白偶联雌激素受体（GPER）是否可通过作用于内质网应激（ERS）来减轻脑缺血再灌注损伤（CIRI）下的海马神经元损伤。采用大脑中动脉闭塞（MCAO）法建立CIRI动物模型。将雌性去卵巢（OVX）的Sprague-Dawley（SD）大鼠随机分为4组：对照组、缺血再灌注损伤组（MCAO）、溶剂对照组（MCAO+二甲基亚砜）和GPER特异性激动剂G1组（MCAO+G1）。采用Longa评分法评估神经行为学评分，通过尼氏染色观察神经元的形态变化，通过TTC染色检测脑梗死情况，通过TUNEL染色检测海马CA1区神经细胞凋亡。采用免疫荧光染色观察海马CA1区GRP78（78 kDa葡萄糖调节蛋白78）的分布和表达。通过蛋白质印迹法检测GRP78、半胱天冬酶-12、CHOP和半胱天冬酶-3的蛋白表达水平，通过实时聚合酶链反应检测GRP78、半胱天冬酶-12和CHOP的mRNA表达水平。结果显示，MCAO组的神经行为学评分、脑梗死体积、细胞凋亡指数以及GRP78、半胱天冬酶-12和CHOP的蛋白及mRNA表达水平均显著高于对照组。而在MCAO+G1组中，G1逆转了上述变化。这些结果表明，激活GPER可减少海马神经元凋亡并减轻CIRI，其机制可能与抑制ERS有关。
