Department of Clinical Application of Traditional Chinese Medicine Integrated with Western Medicine, Zhaotong Hospital of Traditional Chinese Medicine, Zhaotong 657000, China.
Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China; Traditional Chinese Medicine Clinic, Zhaotong Hospital of Traditional Chinese Medicine, Zhaotong 657000, China.
J Neuroimmunol. 2023 Sep 15;382:578101. doi: 10.1016/j.jneuroim.2023.578101. Epub 2023 May 4.
Ginkgo biloba extract (EGb-761) is well-recognized to have neuroprotective properties. Meanwhile, autophagy machinery is extensively involved in the pathophysiological processes of ischemic stroke. The EGb-761 is widely used in the clinical treatment of stroke patients. However, its neuroprotective mechanisms against ischemic stroke are still not fully understood. The present study was conducted to uncover whether the pharmacological effects of EGb-761 can be executed by modulation of the autophagic/lysosomal signaling axis. A Sprague-Dawley rat model of ischemic stroke was established by middle cerebral artery occlusion (MCAO) for 90 min, followed by reperfusion. The EGb-761 was then administered to the MCAO rats once daily for a total of 7 days. Thereafter, the penumbral tissues were acquired to detect proteins involved in the autophagic/lysosomal pathway including Beclin1, LC-3, SQSTM1/p62, ubiquitin, cathepsin B, and cathepsin D by western blot and immunofluorescence, respectively. Subsequently, the therapeutic outcomes were evaluated by measuring the infarct volume, neurological deficits, and neuron survival. The results showed that the autophagic activities of Beclin1 and LC3-II in neurons were markedly promoted by 7 days of EGb-761 therapy. Meanwhile, the autophagic cargoes of insoluble p62 and ubiquitinated proteins were effectively degraded by EGb-761-augmented lysosomal activity of cathepsin B and cathepsin D. Moreover, the infarction size, neurological deficiencies, and neuron death were also substantially attenuated by EGb-761 therapy. Taken together, our study suggests that EGb-761 exerts a neuroprotective effect against ischemic stroke by promoting autophagic/lysosomal signaling in neurons at the penumbra. Thus, it might be a new therapeutic target for treating ischemic stroke.
银杏叶提取物 (EGb-761) 已被广泛认可具有神经保护作用。同时，自噬机制广泛参与缺血性脑卒中的病理生理过程。EGb-761 广泛用于脑卒中患者的临床治疗。然而，其对缺血性脑卒中的神经保护机制仍不完全清楚。本研究旨在探讨 EGb-761 的药理作用是否可以通过调节自噬/溶酶体信号轴来实现。通过大脑中动脉闭塞 (MCAO) 建立 Sprague-Dawley 大鼠缺血性脑卒中模型，闭塞 90 分钟后再灌注。然后，将 EGb-761 给予 MCAO 大鼠，每天一次，共 7 天。之后，采集半影区组织，通过 Western blot 和免疫荧光分别检测自噬/溶酶体通路中涉及的蛋白，包括 Beclin1、LC-3、SQSTM1/p62、泛素、组织蛋白酶 B 和组织蛋白酶 D。随后，通过测量梗死体积、神经功能缺损和神经元存活来评估治疗效果。结果表明，7 天的 EGb-761 治疗明显促进了神经元中 Beclin1 和 LC3-II 的自噬活性。同时，EGb-761 增强的溶酶体活性可有效降解不溶性 p62 和泛素化蛋白等自噬底物。此外，EGb-761 治疗还显著减轻了梗死面积、神经功能缺损和神经元死亡。综上所述，本研究表明，EGb-761 通过促进半影区神经元中的自噬/溶酶体信号发挥对缺血性脑卒中的神经保护作用。因此，它可能成为治疗缺血性脑卒中的新治疗靶点。
