[关键词]
[摘要]
目的 基于核苷酸结合寡聚化结构域样受体蛋白1(NLRP1)和NLRP3炎症小体途径探讨竹节参总皂苷(SPJ)减轻衰老大鼠神经细胞凋亡的作用。方法 以自然衰老大鼠为研究对象,将SPF级SD雄性大鼠随机分为对照组(9月龄)、模型组(24月龄)和SPJ低、中、高剂量组,从18月龄开始,SPJ低、中、高剂量组分别ig给予SPJ 10、30、60 mg/kg,衰老模型组ig等量生理盐水,给药至24月龄,每周停药2 d,持续给药6个月。TUNEL法检测衰老大鼠皮层和海马区神经细胞凋亡情况,Western blotting法检测衰老大鼠皮层和海马区白细胞介素-1β(IL-1β)、IL-18、凋亡相关微粒蛋白(ASC)、NLRP1、NLRP3、半胱氨酸天冬氨酸蛋白酶1(Caspase-1)表达量的变化。结果 TUNEL实验结果显示,对照组中仅见极少数凋亡细胞;与对照组相比,模型组中凋亡细胞数明显增加。与模型组相比,SPJ组大鼠大脑皮层和海马CA1、CA3、DG区凋亡细胞数明显下降。Western blotting结果表明,大鼠大脑皮层和海马组织中IL-1β、ASC、NLRP3、NLRP1、Caspase-1、IL-18的蛋白表达水平均随着年龄的增长而逐渐上调;给药6个月后,SPJ各剂量组均能下调IL-1β、IL-18、ASC、NLRP3、NLRP1、Caspase-1蛋白的表达水平。结论 SPJ对衰老大鼠脑组织(皮层和海马)神经元损伤具有保护作用,其机制可能与其调节NLRP1和NLRP3炎症小体途径,从而减轻炎症反应有关。
[Key word]
[Abstract]
Objective To observe the effects of saponins from Panax japonicus on neuronal apoptosis of natural aging rats and its mechanisms based on NLRP1 and NLRP3 inflammasome pathway. Methods Male SD rats in a SPF grade were randomly divided into five groups:control group (9-month-old rats), model group (24-month-old rats), and SPJ treatment group (10, 30, and 60 mg/kg). From the beginning of 18 months, animals were treated with SPJ (or normal saline) by ig until 24 months, and stopped 2 d each week for six months of continuous administration. The neural apoptosis situation of cortex and hippocampus in aging rats were observed by TUNEL method. The protein expression of IL-1β, ASC, NLRP3, NLRP1, Caspase-1, and IL-18 of the cerebral cortex and hippocampal were detected by Western blotting. Results TUNEL results showed that there were a very small number of apoptotic cells in the cortex and hippocampus in control group. Compared with control group, the model group significantly increased the number of apoptotic cells. Compared with model group, the number of apoptotic cells was significantly decreased in rat cortex and hippocampus (CA1, CA3, and DG) after treated with SPJ (10, 30, and 60 mg/kg). Western blotting results showed a significant age-related increase in the expression of IL-1β, ASC, NLRP3, NLRP1, Caspase-1, and IL-18, while SPJ concentration-dependently decreased the levels of IL-1β, ASC, NLRP3, NLRP1, Caspase-1, and IL-18 after six-month treatment. Conclusion In conclusion, saponins from P. japonicus has protective effects on the brain (cortex and hippocampus) of aging rats. The mechanism is likely to be that saponins from P. japonicus can reduce nerve inflammation by regulating NLRP1 and NLRP3 inflammasome pathway.
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[基金项目]
国家自然科学基金资助项目(81374001)