三七总皂苷对脑缺血再灌注小鼠脑组织自噬水平的调节机制分析

Mechanism of Panax Notoginseng Saponins on Autophagy Level of Brain Tissue after CIRI in Mice

目的:观察三七总皂苷对脑缺血再灌注损伤小鼠脑组织自噬的影响,探讨其对脑组织保护作用的机制。方法:将64只小鼠随机分为假手术组、模型组、三七总皂苷低剂量(60 mg/kg)组、三七总皂苷高剂量(120 mg/kg)组,每组16只。采用改良栓线法复制小鼠脑缺血再灌注模型,手术当天给药,连续给药3 d,1次/d。随后采用ZeaLonga评分法进行小鼠神经功能评分,采用干/湿称质量法检测脑含水量,TTC染色检测脑梗死范围,使用Western Blot法检测小鼠脑缺血侧皮层Bcl-2相互作用蛋白(Beclin 1)、选择性自噬底物蛋白P62、微管相关蛋白1轻链3(LC3)表达水平的变化。结果:与假手术组相比,模型组小鼠神经功能评分、脑梗死范围百分比和脑含水量明显增加(P<0.01),自噬相关蛋白Beclin 1和LC3-Ⅱ/LC3-Ⅰ比值增加(P<0.05,P<0.01),P62表达下调(P<0.05)。与模型组组比较,三七总皂苷组小鼠神经功能损伤明显改善,脑梗死范围百分比减小,自噬相关蛋白Beclin 1和LC3-Ⅱ/LC3-Ⅰ比值降低(P<0.05),P62表达上调(P<0.05)。结论:三七总皂苷能减轻脑缺血再灌注造成的损伤,其可能通过抑制自噬的过度激活。

Objective:To observe the effect of Panax Notoginseng Saponins(PNS)on autophagy in mice with cerebral ischemia-reperfusion injury(CIRI),and to explore the mechanism of its protective effect on cerebral tissues.Methods:64 mice were randomly divided into the sham operation group,the model group and the PNS groups of low-dose(60 mg/kg)and high-dose(120 mg/kg),with 16 mice in each group.CIRI model was induced by modified thread occlusion(MCAO)in mice.The PNS groups were intervened on the day of the operation,once a day for three days.ZeaLonga score was used to score the nerve function of the mice,cerebral infarct size was measured by TTC staining,brain water content was detected with dry/wet specific gravity method,and the expressions of autophagy related proteins Bcl-2 interacting coiledcoil protein 1(Beclin 1),P62 and microtubule-associated protein 1 light chain 3(LC3)were determined by Western Blot.Results:Compared with those in the sham operation group,the neurological deficit scores,the percentage of cerebral infarct and the brain water content were increased(P<0.01),the expressions of Beclin 1 and LC3-II/LC3-I were increased(P<0.05,P<0.01),and the expression of P62 was remarkably down-regulated in the model group(P<0.01).Compared with those in the model group,the neurological deficits were markedly ameliorated,the percentage of cerebral infarct and the brain water content were significantly decreased,the expressions of Beclin 1 and LC3-II/LC3-I were significantly reduced(P<0.05),and the expression of P62 was remarkably up-regulated in the PNS groups(P<0.05).Conclusion:PNS can alleviate CIRI,which may through suppressing the over-activation of autophagy.