Department of Pharmacology, College of Basic Medicine, Kunming Medical University, Kunming, 650500, Yunnan, China.
Sansom Institute for Health Research, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, 5001, Australia.
Neurochem Res. 2018 Oct;43(10):1927-1937. doi: 10.1007/s11064-018-2612-x. Epub 2018 Aug 30.
Artificial abnormal microenvironment caused by microperfusion of L-glutamate (Glu) and Ca in the hippocampus results in neuron damage, which is closely related to cerebral ischemia. Ginsenoside Rb1, a compound from Panax notoginseng, was previously used to counter the artificial abnormal hippocampal environment in a microperfusion model. In addition, while the Akt/mTOR/PTEN signaling pathway has been shown to mediate neuronprotection in cerebral ischemia, whether this pathway is involved in the neuroprotection of ginsenoside Rb1 is unknown. Here SH-SY5Y cells exposed to OGD/R injury in treated with LY294002, ginsenoside Rb1, ginsenoside Rb1+ LY294002. Expressions of phosphorylation (P-)Akt/P-mTOR/P-PTEN (24 h after OGD/R) were detected by Western blotting. Effects were examined via the memory function of rats (by Morris water maze test), morphological changes in pyramidal cell (by histology), and mRNA expression (by qRT-PCR) and phosphorylation (P-) (by Western blotting and immunohistochemical staining) of Akt, P-mTOR, and P-PTEN in the hippocampus. The memory deficit of rats and pyramidal cellular necrosis and apoptosis in the CA1 region of hippocampus after microperfusion of Glu and Ca were dose dependently alleviated by ginsenoside Rb1.Moreover,Western blot showed that ginsenoside Rb1 increased the expressions of P-Akt, P-mTOR and reduced P-PTEN in vivo and vitro. Thus, the potent neuroprotection of ginsenoside Rb1 in artificial abnormal microenvironment is, at least partially, related to the activation of P-AKT/P-mTOR signaling pathway and inhibition of P-PTEN protein.
人工微灌流 L-谷氨酸（Glu）和 Ca 引起的海马异常微环境导致神经元损伤，这与脑缺血密切相关。三七总皂苷 Rb1 是三七的一种化合物，以前用于对抗微灌流模型中的人工异常海马环境。此外，尽管 Akt/mTOR/PTEN 信号通路已被证明可介导脑缺血中的神经元保护，但该通路是否参与人参皂苷 Rb1 的神经保护作用尚不清楚。在这里，将 SH-SY5Y 细胞暴露于 OGD/R 损伤中，并用 LY294002、人参皂苷 Rb1、人参皂苷 Rb1+LY294002 处理。通过 Western blot 检测 OGD/R 后 24 小时磷酸化（P-）Akt/P-mTOR/P-PTEN 的表达。通过 Morris 水迷宫测试评估大鼠的记忆功能，通过组织学评估锥体细胞的形态变化，通过 qRT-PCR 和 Western blot 和免疫组织化学染色评估 Akt、P-mTOR 和 P-PTEN 的 mRNA 表达和磷酸化（P-）在海马中的表达。Glu 和 Ca 微灌流后大鼠的记忆缺陷以及海马 CA1 区锥体细胞坏死和凋亡呈剂量依赖性地被人参皂苷 Rb1 减轻。此外，Western blot 表明人参皂苷 Rb1 增加了体内和体外 P-Akt、P-mTOR 的表达，并降低了 P-PTEN 的表达。因此，人参皂苷 Rb1 在人工异常微环境中的强大神经保护作用至少部分与 P-AKT/P-mTOR 信号通路的激活和 P-PTEN 蛋白的抑制有关。
