State Key Laboratory of Natural Products, Jiangsu Key Laboratory of TCM Evaluation and Translational Research, Department of Pharmacology of Chinese Material Medica, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China.
State Key Laboratory of Natural Products, Jiangsu Key Laboratory of TCM Evaluation and Translational Research, Department of Resource and Developmemt of Chinese Material Medica, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China.
Molecules. 2019 Oct 8;24(19):3624. doi: 10.3390/molecules24193624.
The neuroprotective role of schizandrin (SA) in cerebral ischemia-reperfusion (I/R) was recently highlighted. However, whether SA plays a regulatory role on autophagy in cerebral I/R injury is still unclear. This study aimed to explore whether the neuroprotective mechanisms of SA were linked to its regulation of AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR)/autophagy pathway in vivo and in vitro. The present study confirmed that SA significantly improved oxygen-glucose deprivation/re-oxygenation (OGD/R)-induced PC12 cells injury. The results of immunoblotting and confocal microscope showed that SA decreased autophagy in OGD/R-injured PC12 cells, which was reflected by the decreased Beclin-1 and LC3-II expression, autophagy flux level, and LC3 puncta formation. In addition, the autophagy inducer rapamycin partially prevented the effects of SA on cell viability and autophagy after OGD/R, whereas the autophagy inhibitor 3-methyladenine (3-MA) exerted the opposite effect. The results of Western blotting showed that SA markedly decreased the phosphorylation of AMPK (p-AMPK), whereas the phosphor-mTOR (p-mTOR) levels increased in the presence of OGD/R insult. Furthermore, pretreatment with the AMPK inducer AICAR partially reversed the protective effects and autophagy inhibition of SA. However, AMPK inhibitor Compound C pretreatment further promoted the inhibition of SA on autophagy induction and cell damage induced by OGD/R. Taken together, these findings demonstrate that SA protects against OGD/R insult by inhibiting autophagy through the regulation of the AMPK-mTOR pathway and that SA may have therapeutic value for protecting neurons from cerebral ischemia.
五味子醇甲（SA）在脑缺血再灌注（I/R）中的神经保护作用最近受到了关注。然而，SA 是否在脑 I/R 损伤中对自噬起调节作用尚不清楚。本研究旨在探讨 SA 的神经保护机制是否与其在体内和体外对 AMP 激活的蛋白激酶（AMPK）/雷帕霉素靶蛋白（mTOR）/自噬途径的调节有关。本研究证实，SA 可显著改善氧葡萄糖剥夺/复氧（OGD/R）诱导的 PC12 细胞损伤。免疫印迹和共聚焦显微镜的结果表明，SA 降低了 OGD/R 损伤的 PC12 细胞中的自噬，这反映在 Beclin-1 和 LC3-II 表达、自噬流水平和 LC3 斑点形成减少。此外，自噬诱导剂雷帕霉素部分预防了 OGD/R 后 SA 对细胞活力和自噬的影响，而自噬抑制剂 3-甲基腺嘌呤（3-MA）则产生相反的效果。Western blot 的结果表明，SA 明显降低了 AMPK 的磷酸化（p-AMPK），而在 OGD/R 损伤存在的情况下，p-mTOR（p-mTOR）水平增加。此外，用 AMPK 诱导剂 AICAR 预处理部分逆转了 SA 的保护作用和自噬抑制作用。然而，AMPK 抑制剂 Compound C 预处理进一步促进了 SA 对 OGD/R 诱导的自噬诱导和细胞损伤的抑制作用。总之，这些发现表明，SA 通过调节 AMPK-mTOR 通路抑制自噬来保护 OGD/R 损伤，并且 SA 可能对保护神经元免受脑缺血具有治疗价值。
