内质网应激PERK-ATF4-CHOP信号通路参与慢性应激大鼠下丘脑神经细胞损伤  

PERK-ATF4-CHOP pathway in stressed endoplasmic reticulum is involved in hypothalamic neuronal injury in rats with chronic stress

作　　者：史为博[1] 易善勇[1] 王贺[1] 牛世霸 王松军[1] 李英敏[1] 丛斌[1] Shi Weibo;Yi Shanyong;Wang He;Niu Shiba;Wang Songjun;Li Yingminm;Cong Bin(Department of Forensic Medicine, Hebei Medical University, Hebei Key Laboratory of Forensic Medicine, Collaborative Innovation Center of Forensic Medical Molecular Identification, Shijiazhuang 050017, China)

机构地区：[1]河北医科大学法医学系河北省法医学重点实验室河北省法医分子鉴定协同创新中心,石家庄050017

出　　处：《解剖学杂志》2018年第3期280-284,共5页Chinese Journal of Anatomy

基　　金：河北省科学自然基金(H2017206231);河北省教育厅重点项目(ZD2016060)

摘　　要：本研究旨在探讨不同时程应激过程中,下丘脑神经细胞是否启动内质网应激,并通过影响HPA轴,引发神经细胞病理性改变,为应激导致的神经细胞损伤机制提供依据。建立每日束缚固定8 h加冰水游泳5 min的应激大鼠模型,分为1、3、7、14、21 d组及各时间点正常对照组,ELISA检测血清中糖皮质激素水平变化,硫堇染色观察下丘脑神经细胞病理形态学改变,免疫组织化学显色观察下丘脑神经细胞中内质网应激蛋白GRP78、ATF4和CHOP的表达变化以及采用全景组织细胞定量分析系统(MMTC),进行蛋白表达的半定量分析。糖皮质激素从应激第3天开始显著升高,7 d达到高峰,21 d时又显著性降低;硫堇染色显示随应激时间的延长,下丘脑神经细胞发生水肿,尼氏体消失,细胞固缩浓染的病理性改变;免疫组织化学显色及MMTC法分析显示内质网应激蛋白GRP78的表达呈现出先增高后降低趋势,ATF4和CHOP的表达随着应激时间的延长显著性增加。应激导致大鼠下丘脑神经细胞的病理性改变,同时内质网应激相关蛋白呈现出显著的动态变化,提示内质网应激PERK-ATF4-CHOP通路的激活可能参与了下丘脑神经细胞的病理性损伤。To determine whether endoplasmic reticulum stress in hypothalamic neurons is differentially stimulated by varying durations of stress exposure, which ultimately leads to pathological changes in neurons by affecting HPA axis function and to provide evidence for the mechanism involved in stress-induced neuron injury. Methods： A stress model was established in rats by 8 h restraint and forced ice-water swimming for 5 minutes each day. The stress-inducing process lasted for 1, 3, 7, 14, 21 days, respectively. Enzyme-linked immunosorbent assay （ELISA） was used to assay serum glucocorticoid levels. Thionine staining was used to observe morphological changes in hypothalamic neurons. Immunohistochemistry and microscopy-based multicolor tissue cytometry （MMTC） were used to detect expression of endoplasmic reticulum stress protein GRP78, ATF4 and CHOP. Results： Serum glucocorticoid level significantly increased after 3 days of stress exposure and the level peaked on day 7. By day 21, however, the level was significantly decreased. Thionine staining revealed that prolonged stress exposure resulted in edema, a lack of Nissl bodies, and pyknotic neurons in hypothalamic neurons. Imrnunohistochemistry and MMTC showed that increasing stress period significantly decreased GRP78 expression, although ATF4 and CHOP protein expression significantly increased. Conclusion： Stress results in pathological changes and significant dynamic changes because of endoplasmic reticulum stress in hypothalamic neurons of rats. These results suggest that the endoplasmic reticulum stress PERK-ATF4-CHOP pathway may be associated with hypothalamic neuronal injury.

关 键 词：下丘脑 下丘脑-垂体-肾上腺轴 糖皮质激素 应激 PERK-ATF4-CHOP通路 

分 类 号：R363[医药卫生—病理学]