表没食子儿茶素没食子酸酯对APP/PS1转基因小鼠海马IRS-1磷酸化的影响

The impact of epigallocatechin-3-gallate(EGCG)on expression of the phosphorylation of IRS-1 in the hippocampus of APP/PS1 transgenetic mice

目的:观察表没食子儿茶素没食子酸酯(EGCG)对APP/PS1转基因小鼠海马胰岛素受体底物-1(IRS-1)磷酸化的作用。方法:12月龄雌性APP/PS1小鼠随机分为模型组(Tg)、EGCG低剂量组(Tg/EGCG-L)、高剂量组(Tg/EGCG-H),同月龄雌性C57BL/6J小鼠作为对照组(NT)。采用Western blot和免疫组织化学方法检测各组小鼠海马IRS-1pSer636的表达。结果:与对照组比较,模型组小鼠海马IRS-1pSer636表达明显升高(P<0.05),EGCG各治疗组IRS-1pSer636表达较模型组降低(P<0.05)。结论:EGCG可以减轻APP/PS1小鼠海马胰岛素抵抗,其机制可能部分与减轻IRS-1在丝氨酸636位点的磷酸化水平有关。

OBJECTIVE To observe the effects of epigallocatechin-3 gallate （EGCG） on the expression of insulin receptor substrate-l（IRS-1） phosphorylation in the hippocampus of APP/PS1 transgenetie mice. METHODS 12 months old female APP/PS1 mice were randomly divided into 3 groups： model group（Tg）, EC, CG low dose group （Tg /EGCC-L）, high dose group（Tg/EGCG-H）. C57BL/6J mice were utilized as control. The hippocampal IRS-lpSer636 level of each group was detected by Western blot and Immunohistochemical staining. RESULTS Compared with NT mice, the hippocampal IRS-lpSer636 level of Tg mice was increased significantly （P〈0. 05）, Tg/EGCG-L and Tg/EGCG-H mice showed an obvious decrease of IRS-lpSer636 level in the hippocampus compared with Tg mice（P〈0. 05）. CONCLUSION EGCG treatment is able to alleviate insulin resistance in the hippocampus of APP/PS1 mice, which may be partly attributed to the reduction of IRS-1pSer636 level in this mice model.