人参皂苷Rb1改善局灶性CIRI小鼠模型神经损伤的调控机制研究

The regulatory mechanism of ginsenoside Rb1 to improve nerve injury in focal CIRI mouse model

目的探究人参皂苷Rb1对局灶性脑缺血再灌注损伤(CIRI)的调控机制。方法60只C57/BL小鼠随机分为6组(n=10):假手术组、CIRI模型组、人参皂苷Rb1低、中、高剂量组和尼莫地平(阳性对照)组。手术方法构建局灶性CIRI小鼠模型。行神经功能评分、行为学测试,尼氏染色检测海马体中尼氏体数量。qPCR、Western blot和免疫组化检测人参皂苷Rb1对海马体中Wnt信号通路分子表达的影响,通过分子对接和共沉淀实验研究人参皂苷Rb1的调控机制。结果与CIRI模型组相比,添加人参皂苷Rb1后能够降低小鼠神经功能评分(P<0.05),降低通过平衡木时间(P<0.05),提高小鼠进入正确臂时间(P<0.05),增加小鼠摇摆时间和攀爬时间(P<0.05),证明了人参皂苷Rb1能够有效恢复小鼠神经系统功能,提高模型小鼠行为学能力。人参皂苷Rb1治疗后海马体中轴抑制蛋白2(Axin2)和糖原合成酶激酶-3β(GSK-3β)降低,Wnt3a、Wnt1和β-连锁蛋白(β-catenin)表达量增加。结论人参皂苷Rb1能够改善CIRI小鼠模型的神经功能并提高海马体中尼氏体数量,与激活Wnt信号通路有关,可能在卒中治疗期间对局灶性CIRI具有神经保护作用。

Objective To explore the regulatory mechanism of ginsenoside Rb1 on focal cerebral ischemia-reperfusion injury(CIRI).Methods A total of 60 C57/BL mice were randomly divided into 6 groups(n=10):sham-operated group,CIRI model group,ginsenoside Rb1 low-,medium-,and high-dose group and nimodipine(positive control)group.The surgical method was used to construct the focal CIRI mouse model.The neurological function scores and behavioral tests were performed,and Nissl staining was utilized to detect the number of nissl bodies in the hippocampus.The effect of ginsenoside Rb1 on the molecule expression of the Wnt signaling pathway in the hippocampus was detected by qPCR,Western blot and immunohistochemistry assays.The regulatory mechanism of ginsenoside Rb1 was investigated through molecular docking and co-precipitation assays.Results Compared with the CIRI model group,the addition of ginsenoside Rb1 reduced the neurological function scores of mice(P<0.05),shortened the time passing the balance beam(P<0.05),but increased the time entering the correct arm(P<0.05)and the swinging time and climbing time of mice(P<0.05),indicating that ginsenoside Rb1 could effectively resume the function of the nervous system in mice and improve the behavioral ability of model mice.After ginsenoside Rb1 treatment,axis inhibition protein 2(Axin2)and glycogen synthase kinase-3β(GSK-3β)in the hippocampus decreased,whereas the expression of Wnt3a,Wnt1 andβ-catenin increased.Conclusion The ginsenoside Rb1 can improve neurological function of the CIRI mouse model and increase the number of Nissl bodies in the hippocampus,which is correlated with the activation of the Wnt signaling pathway,and it may be neuroprotective against focal CIRI during stroke treatment.