Ren Kai-Di, Peng Zi-Mei, Tian Jing, Peng Ya-Wei, Zhang Yi-Yue, Zhang Xiao-Jie, Hu Zhong-Yang, Luo Xiu-Ju, Peng Jun
Department of Pharmacology, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, 410078, China.
Hunan Provincial Key Laboratory of Cardiovascular Research, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, 410078, China.
CNS Neurol Disord Drug Targets. 2022;21(8):693-703. doi: 10.2174/1871527320666211118143554.
Upregulation of mitochondrial E3 ubiquitin ligase 1 (Mul1) contributes to brain injury in ischemic stroke due to disturbance of mitochondrial dynamics, and bioinformatics analysis predicts that Mul1 is a potential target of Dipsacoside B.
The aim of the study was to explore whether Dipsacoside B can exert a beneficial effect on brain injury in the ischemic stroke rat via targeting Mul1.
The SD rat brains or PC12 cells were subjected to 2 h-ischemia or 8 h-hypoxia plus 24 h-reperfusion or 24 h-reoxygenation to establish the ischemic stroke rat model in vivo or in vitro, which were treated with Dipsacoside B at different dosages. The brain or PC12 cell injury, relevant protein levels and mitochondrial functions were measured by methods of biochemistry, flow cytometry or Western blot.
The neurological dysfunction and brain injury (such as infarction and apoptosis) observed in the ischemic stroke rats were accompanied by increases in Mul1 and Dynamin-related protein 1 (Drp1) levels along with decreases in mitofusin 2 (Mfn2) level and ATP production. These effects were attenuated by Dipsacoside B. Consistently, cell injury (necroptosis and apoptosis) occurred in the PC12 cells exposed to hypoxia concomitant with the upregulation of Mul1 and Drp1 along with downregulation of Mfn2 and mitochondrial functions (such as increases in reactive oxygen species production and mitochondrial fission and decreases in mitochondrial membrane potential and ATP production).These phenomena were reversed in the presence of Dipsacoside B.
Dipsacoside B can protect the rat brain against ischemic injury via inhibition of Mul1 due to the improvement of mitochondrial function.
线粒体E3泛素连接酶1（Mul1）的上调因线粒体动力学紊乱而导致缺血性脑卒中脑损伤，生物信息学分析预测Mul1是续断皂苷B的潜在靶点。
本研究旨在探讨续断皂苷B是否可通过靶向Mul1对缺血性脑卒中大鼠脑损伤发挥有益作用。
对SD大鼠脑或PC12细胞进行2小时缺血或8小时缺氧加24小时再灌注或24小时复氧，以建立体内或体外缺血性脑卒中大鼠模型，并用不同剂量的续断皂苷B进行处理。通过生物化学、流式细胞术或蛋白质印迹法测量脑或PC12细胞损伤、相关蛋白水平和线粒体功能。
在缺血性脑卒中大鼠中观察到的神经功能障碍和脑损伤（如梗死和凋亡）伴随着Mul1和动力相关蛋白1（Drp1）水平的升高，以及线粒体融合蛋白2（Mfn2）水平和ATP生成的降低。这些效应被续断皂苷B减弱。同样，暴露于缺氧环境的PC12细胞发生细胞损伤（坏死性凋亡和凋亡），同时Mul1和Drp1上调，Mfn2和线粒体功能下调（如活性氧生成增加、线粒体分裂增加，线粒体膜电位和ATP生成减少）。在续断皂苷B存在的情况下，这些现象得到逆转。
续断皂苷B可通过抑制Mul1改善线粒体功能，从而保护大鼠脑免受缺血性损伤。
