半枝莲黄酮对Aβ_(25-35)引起的大鼠皮层星形胶质细胞NOS、HSP70及apoE异常表达的影响

Effects of Scutellaria barbata flavonoids on abnormal expression of NOS,HSP70 and apoE induced by Aβ_(25-35) in rat astrocytes

目的：探讨半枝莲黄酮对Aβ25-35引起大鼠皮层星形胶质细胞一氧化氮合酶（NOS）热休克蛋白70（HSP70）及载脂蛋白E（apoE）蛋白表达异常变化的影响。方法：培养第3代的大鼠星形胶质细胞随机分为空白对照组、模型组和3个剂量药物组，药物组细胞分别加入17．5、35和70mg／L半枝莲黄酮作用24h后，模型组和3个剂量药物组均加人Aβ25-35 100μmoL／L作用24h，免疫组化法测定星形胶质细胞中内皮型一氧化氮合酶（eNOS）、诱导型一氧化氮合酶（iNOS）和神经元型一氧化氮合酶（nNOS）蛋白的表达；Western blotting检测星形胶质细胞中HSP70蛋白的表达；RT—PCR测定细胞中apoE mRNA的表达。结果：与空白组相比，模型组eNOS蛋白含量降低60．83％（P〈0．01），iNOS蛋白含量增加215．03％（P〈0．01），HSP70蛋白含量增加166．67％（P〈0．01），apoE mR—NA含量增加150．00％（P〈0．01）；半枝莲黄酮17．5、35及70mg／L能不同程度地提高eNOS蛋白含量73．66％～137．77％（P〈0．05），降低iNOS蛋白含量19．40％～44．50％（P〈0．01），降低HSP70蛋白含量18．52％-49．38％（P〈0．01），降低apoE mRNA的含量14．17％-41．67％（P〈0．01）。结论：半枝莲黄酮对Aβ25-35引起的大鼠皮层星形胶质细胞的损伤具有抑制作用。半枝莲黄酮可能通过影响星形胶质细胞发挥对阿尔茨海默病的治疗作用。

AIM ： To study the effects of Scutellaria barbata flavonoids （SBF） on abnormal expression of nitric oxide synthase （NOS）, heat-shock protein 70 （HSP70） and apolipoprotein E （apoE） induced by Aβ25-35 in rat astrocytes. METHODS ： The third generation of cultured rat astrocytes was divided into 5 groups. The ceils in 3 drug treatment groups were given SBF at dose of 17.5 mg/L, 35 mg/L and 70 mg/L for 24 h, and then the cells in model group and 3 doses of SBF groups were exposed to Aβ25-35 at concentration of 100 μmol/L for 24 h. The expression of endothelial nitric oxide syn- thase （eNOS）, inducible nitric oxide synthase （iNOS） and neuronal nitric oxide synthase （nNOS） in the cultured cells was assayed by immunohistochemical method. The expression of HSP70 was estimated by Western blotting and the mRNA expression of apoE was assessed by RT-PCR. RESULTS ： Compared with control group, the protein level of eNOS were significantly decreased and the protein level of iNOS increased （ P 〈 0.01 ） in model group. The protein expression of HSP70 and mRNA expression of apoE were notably increased （P 〈 0. 01 ） in model group. However, these disturbances were attenuated by SBF at dose of 17.5, 35 and 70 mg/L （P 〈0.01 ）. CONCLUSION： SBF has an obvious protective effect on damaged astrocytes induced by Aβ25-35, suggesting that SBF may be helpful for the treatment of Alzheimer disease.