Cao Yin, Yang Yingbo, Wu Hui, Lu Yi, Wu Shuang, Liu Lulu, Wang Changhong, Huang Fei, Shi Hailian, Zhang Beibei, Wu Xiaojun, Wang Zhengtao
Shanghai Key Laboratory of Compound Chinese Medicines, The Ministry of Education (MOE) Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
J Ginseng Res. 2020 May;44(3):442-452. doi: 10.1016/j.jgr.2019.01.009. Epub 2019 Feb 6.
Sleep deprivation (SD) impairs learning and memory by inhibiting hippocampal functioning at molecular and cellular levels. Abnormal autophagy and apoptosis are closely associated with neurodegeneration in the central nervous system. This study is aimed to explore the alleviative effect and the underlying molecular mechanism of stem-leaf saponins of (SLSP) on the abnormal neuronal autophagy and apoptosis in hippocampus of mice with impaired learning and memory induced by SD.
Mouse spatial learning and memory were assessed by Morris water maze test. Neuronal morphological changes were observed by Nissl staining. Autophagosome formation was examined by transmission electron microscopy, immunofluorescent staining, acridine orange staining, and transient transfection of the tf-LC3 plasmid. Apoptotic event was analyzed by flow cytometry after PI/annexin V staining. The expression or activation of autophagy and apoptosis-related proteins were detected by Western blotting assay.
SLSP was shown to improve the spatial learning and memory of mice after SD for 48 h, accomanied with restrained excessive autophage and apoptosis, whereas enhanced activation of phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway in hippocampal neurons. Meanwhile, it improved the aberrant autophagy and apoptosis induced by rapamycin and re-activated phosphoinositide 3-kinase/Akt/mammalian target of rapamycin signaling transduction in HT-22 cells, a hippocampal neuronal cell line.
SLSP could alleviate cognitive impairment induced by SD, which was achieved probably through suppressing the abnormal autophagy and apoptosis of hippocampal neurons. The findings may contribute to the clinical application of SLSP in the prevention or therapy of neurological disorders associated with SD.
睡眠剥夺（SD）通过在分子和细胞水平抑制海马功能来损害学习和记忆。异常的自噬和凋亡与中枢神经系统的神经退行性变密切相关。本研究旨在探讨三叶人字草茎叶皂苷（SLSP）对SD诱导的学习记忆受损小鼠海马神经元异常自噬和凋亡的缓解作用及其潜在分子机制。
通过Morris水迷宫试验评估小鼠的空间学习和记忆能力。采用尼氏染色观察神经元形态变化。通过透射电子显微镜、免疫荧光染色、吖啶橙染色和tf-LC3质粒瞬时转染检测自噬体形成。PI/膜联蛋白V染色后通过流式细胞术分析凋亡事件。采用蛋白质印迹法检测自噬和凋亡相关蛋白的表达或激活情况。
结果显示，SLSP可改善SD 48小时后小鼠的空间学习和记忆能力，同时抑制过度的自噬和凋亡，增强海马神经元中磷酸肌醇3激酶/蛋白激酶B/雷帕霉素哺乳动物靶点信号通路的激活。此外，它还改善了雷帕霉素诱导的异常自噬和凋亡，并重新激活了海马神经元细胞系HT-22细胞中的磷酸肌醇3激酶/蛋白激酶B/雷帕霉素哺乳动物靶点信号转导。
SLSP可减轻SD诱导的认知障碍，这可能是通过抑制海马神经元的异常自噬和凋亡实现的。这些发现可能有助于SLSP在预防或治疗与SD相关的神经疾病中的临床应用。
