丹参酮对于阿尔茨海默症大鼠颞叶iNOS,MMP-2表达的影响及机理研究

The Effect of Tanshinone on the Expression of iNOS, MMP-2 in Temporal of Alzheimer's Disease Model Rats and Study on Mechanism

目的:应用中药丹参酮(tanshinone IIA,Tan IIA)治疗AD大鼠,观察TanⅡA干预前后,AD大鼠学习记忆、颞叶中诱导型一氧化氮合成酶(iNOS)、基质金属蛋白酶(MMP-2)表达的变化。方法:采用β-淀粉样蛋白(Aβ)定向注射法建立AD大鼠模型,并使用Tan II A干预,通过避暗测试、real-time PCR和Western Blot分别观察大鼠学习记忆能力、大鼠颞叶MMP-2、iNOS两者的mRNA及蛋白表达的变化。应用SPSS13.0进行统计学分析。结果:与假手术组相比,AD组的平均潜伏期缩短(P<0.01),平均错误次数增加(P<0.01),差异均有统计学意义。颞叶内iNOS、MMP-2 mRNA表达均显著增高(P<0.01,P<0.01);两蛋白的表达均显著增高(P<0.01,P<0.01)。与AD组相比,Tan IIA组的平均潜伏期延长(P<0.01),平均错误次数减少(P<0.01),差异均有统计学意义。颞叶内iNOS、MMP-2 mRNA表达均显著下降(P<0.05,P<0.05),两蛋白的表达均显著下降(P<0.01,P<0.01)。结论:Tan II A干预可显著降低AD大鼠颞叶中iNOS、MMP-2 mRNA及蛋白的表达,显著改善AD大鼠的学习记忆能力。其作用机制可能是通过降低Aβ诱导的iNOS及MMP-2的表达,抑制氧化应激损伤来完成。

Objective： To investigate the influence oftanshinone Ⅱ A （Tan Ⅱ A） on the learning and memory ability, the expression of the inducible nitric oxide synthase （iNOS）, matrix metalloproteinase Ⅱ （MMP-2） in temporal of Alzheimer＇s disease （AD） model rats. Methods： AD model rats were established by direct β-amyloid protein （Aβ） injection method. For Tan Ⅱ A intervention test, the learning and memory ability of AD rats were observed by passive avoidance task test, the expression of iNOS, MMP-2 at mRNA and protein levels in temporal region were compared by real-time PCR and Western Blot respectively. Using SPSS 13.0 to statistic analyse the data. Results： Compared with sham-operation group, the average latency time of passive avoidance task test in AD group was decreased （P〈 0.01）, and the average wrong times of passive avoidance task test in AD group was significantly increased （P〈 0.01）. Both mRNA and protein expressions of iNOS, MMP-2 in temporal were significantly increased （mRNA;P〈 0.01, P〈 0.01; protein： P〈0.01, P〈0.01）. Compared with AD group, the average latency time in Tan Ⅱ A group was significantly increased （P〈0.01）, and the average wrong times in Tan Ⅱ A group was significantly decreased（P〈0.01）. Both mRNA and protein expressions of iNOS, MMP-2 of temporal in Tan ⅡA group were significantly decreased respectively （mRNA：P〈0.05, P〈0.05; protein： P〈 0.01, P〈 0.01）. Conclusion： Tan Ⅱ A can effectively en- hance the ability of learning and memory of AD rats, significantly decrease mRNA and protein expressions of iNOS, MMP-2 in temporal of AD rats. This mechanism is probably inhibiting iNOS and MMP-2 expressions induced by Aβ in AD rats through suppressing oxidative injury.