补阳还五汤基于AMPK/ULK1自噬信号通路抑制脑缺血再灌注损伤的机制研究

Cerebral ischemia-reperfusion injury (CIRI) is an important problem urgently to be solved in ischemic cerebral apoplexy, the mechanism of CIRI has not been fully elucidated. Autophagy plays an important role in the CIRI, AMPK/ULK1 pathway is upstream pathways on the regulation of autophagy and plays a key role in the process of autophagy startup. Chinese medicine believes that qi deficiency and blood stasis are important mechanisms of ischemic stroke, Buyang Huanwu Decoction supplements qi, activating blood, removing phlegm, commonly used for treatment of ischemic stroke. Our group's previous studies confirmed that Buyang Huanwu Decoction can reduce brain injury in rats with middle cerebral artery occlusion by inhibiting apoptosis. And astragaloside IV, the main active ingredient of Astragalus membranaceus, can inhibit apoptosis of PC12 cells induced by hypoxia/hypoglycemia and reoxygenation by regulating autophagy, gives play to the role of neural protection. Therefore, this project puts forward the scientific hypothesis bases on the previous studies: Buyang Huanwu Decoction may reduce CIRI by regulating autophagy through the AMPK/ULK1 pathways.

脑缺血再灌注损伤（CIRI）是缺血性脑卒中亟待解决的重要问题，目前对CIRI的发生机制尚未完全阐明。细胞自噬在CIRI中扮演着重要角色，AMPK/ULK1信号通路是调控细胞自噬的上游通路，在自噬的启动过程中发挥关键作用。中医认为，气虚血瘀是缺血性卒中发生的重要机制，补阳还五汤益气活血化瘀，为治疗缺血性卒中的常用方。本课题组前期研究证实补阳还五汤可通过抑制细胞凋亡减轻大脑中动脉阻塞模型大鼠的脑损伤，其君药黄芪的主要活性成分黄芪甲苷可通过调控自噬抑制缺氧缺糖/复氧复糖PC12细胞凋亡，发挥神经保护作用。因此，本项目在前期研究的基础上，大胆提出科学假说：补阳还五汤通过AMPK/ULK1信号通路调控细胞自噬很可能是其减轻CIRI的重要机制。

脑缺血再灌注损伤是缺血性脑卒中的重要病理过程，AMPK/ULK1信号通路介导的细胞自噬在其中发挥着关键作用。中医认为气虚血瘀是缺血性脑卒中的重要病机，补阳还五汤益气活血化瘀，是治疗缺血性脑卒中的临床常用方，但其作用机制尚不明确。本研究应用SD大鼠和大鼠原代皮层神经元，建立了脑缺血再灌注损伤的在体模型和离体模型。在动物水平，发现补阳还五汤可下调脑缺血再灌注损伤大鼠脑组织AMPK/ULK1信号通路关键蛋白p-AMPK/AMPK、p-ULK1/ULK1和自噬标志蛋白LC3Ⅱ/Ⅰ的表达；在细胞水平，明确了补阳还五汤含药血清能够有效降低氧糖剥夺/复氧复糖（OGD/R）模型神经元中AMPK和ULK1的磷酸化水平，降低Beclin-1和LC3Ⅱ/Ⅰ表达，发挥神经保护作用，揭示了补阳还五汤抗脑缺血再灌注损伤的作用机制，为临床防治缺血性脑卒中提供了理论依据。