Institute of Cerebrovascular Diseases, Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong, China.
Department of Biology, Qingdao University, Qingdao 266021, Shandong, China.
Neuroscience. 2017 Oct 24;362:13-24. doi: 10.1016/j.neuroscience.2017.08.032. Epub 2017 Aug 23.
Neuregulin-1β (NRG-1β) has great potential to be developed into therapeutics for neuroprotection. The aim of the current study was to analyze the effects and possible signaling pathway of NRG-1β on brain tissues in a rat model of middle cerebral artery occlusion/reperfusion (MCAO/R).
In order to observe the protective effect of NRG-1β on MCAO/R, the neurological deficit and infarct volume were measured using a modified neurological severity score (mNSS) test and by triphenyl tetrazolium chloride (TTC) staining. In order to detect the antagonistic effect of NRG-1β on nerve cells and the blood-brain barrier (BBB), the morphology and structure of cortical brain tissues were observed by Evans Blue (EB) staining, hematoxylin-eosin (H&E) and Nissl staining, in situ cell death detection kit, and transmission electron microscopy (TEM). In order to investigate whether NRG-1β exhibited a significant neuroprotective effect via the JNK signaling pathway, the activity of JNK and the levels of phospho-MKK4, phospho-JNK, pan-JNK and phospho-c-Jun were tested using a JNK activity screening kit, immunofluorescent labeling, and western blot analysis, respectively.
In the NRG-1β treatment group, accompanied with a decrease in JNK activity, the protein levels of phospho-JNK, phospho-MKK4 and phospho-c-Jun decreased, the ischemia-induced apoptosis decreased, the abnormal morphological structures of nerve cells were ameliorated, the integrity of the BBB was restored, and infarct volume was reduced. At the same time, neurological function was significantly recovered.
NRG-1β exerts a neuroprotective effect through the JNK signaling pathway in MCAO/R rats.
神经调节蛋白-1β（NRG-1β）在神经保护方面具有巨大的开发潜力。本研究旨在分析 NRG-1β 对大脑中动脉闭塞/再灌注（MCAO/R）大鼠模型脑组织的影响及其可能的信号通路。
为了观察 NRG-1β 对 MCAO/R 的保护作用，采用改良神经功能缺损评分（mNSS）试验和氯化三苯基四氮唑（TTC）染色测量神经功能缺损和梗死体积。为了检测 NRG-1β 对神经细胞和血脑屏障（BBB）的拮抗作用，通过伊文思蓝（EB）染色、苏木精-伊红（H&E）和尼氏染色、原位细胞死亡检测试剂盒和透射电镜（TEM）观察皮质脑组织的形态和结构。为了研究 NRG-1β 是否通过 JNK 信号通路发挥显著的神经保护作用，使用 JNK 活性筛选试剂盒、免疫荧光标记和 Western blot 分析分别检测 JNK 活性、磷酸化 MKK4、磷酸化 JNK、pan-JNK 和磷酸化 c-Jun 的水平。
在 NRG-1β 治疗组中，随着 JNK 活性的降低，磷酸化 JNK、磷酸化 MKK4 和磷酸化 c-Jun 的蛋白水平降低，缺血诱导的细胞凋亡减少，神经细胞的异常形态结构得到改善，BBB 的完整性得到恢复，梗死体积减少。同时，神经功能明显恢复。
NRG-1β 通过 MCAO/R 大鼠的 JNK 信号通路发挥神经保护作用。
