雌激素对去势雌性大脑中动脉栓塞（MCAO）模型大鼠Wnt信号通路的影响

发布时间：2018-04-13 04:16

本文选题：雌激素 + 大脑中动脉阻塞　；参考：《南京医科大学》2017年硕士论文

【摘要】：目的研究外源性雌激素对去势雌性大鼠大脑中动脉阻塞(MCAO)模型经典Wnt信号通路的影响,探讨雌激素在局灶性脑缺血中发挥神经保护作用的机制。方法选取SPF级3个月龄Wistar雌性大鼠60只,采用去势雌性大鼠脑缺血模型,随机分为3组,假手术组、模型组、雌激素组([17β-雌二醇,皮下注射,300μg/kg·d],每组20只。比较3组大鼠MCAO手术后24h的死亡率、神经功能评分、体质量和血清E2水平,2,3,5-三苯基四唑氮红(TTC)染色法评估脑梗死体积,免疫组织化学、蛋白质印迹法测定左侧大脑皮质区Dickkopf相关蛋白-1(Dkk-1蛋白)、大脑皮质结肠腺瘤样息肉病(APC)蛋白、β-连环蛋白和存活素(Survivin)蛋白的表达。结果MCAO手术后24 h时,假手术组、模型组、雌激素组大鼠死亡率分别为0、40%(8/20)和20%(4/20),雌激素组神经功能评分高于模型组(P0.05),模型组和雌激素组死亡率差异无统计学意义(χ~2=1.905,P=0.168)。雌激素组大脑梗死体积([255.43±51.43]mm~3)比模型组([490.75±93.38]mm3)小,2组差异有统计学意义(t=5.565P=0.001)。补充外源性雌激素6周再行MCAO手术后24小时时,大鼠血清E2水平分别假手术组(31.36±1.89)pg/mL,模型组(18.23±1.08)pg/mL,雌激素组(35.07±1.46)pg/mL,3组间差异有统计学意义(F=253.615,P=0.000);三组大鼠体质量分别为假手术组(207.5±8.657)g,模型组(231.429±16.959)g,雌激素组(197.7±10.382)g,3组间差异有统计学意义(F=17.053,P0.001)。免疫组织化学结果提示模型组Dkk-1蛋白表达水平高于其他2组,差异有统计学意义(P均0.05);模型组APC蛋白表达水平高于其他2组,差异有统计学意义(P0.05);雌激素组β-连环蛋白水平高于模型组(P0.05),与假手术组比较差异无统计学意义(P0.05);雌激素组Survivin蛋白表达高于模型组差异均有统计学意义(P均0.05)。蛋白质印迹法结果显示MCAO手术后24小时时,雌激素组DKK-1蛋白表达低于模型组差异均有统计学意义(P0.05);雌激素组APC蛋白表达低于模型组;β-连环蛋白的表达高于模型组,差异均有统计学意义(P均0.05);雌激素组Survivin蛋白表达高于模型组差异均有统计学意义(P均0.05)。结论补充外源性雌激素可以通过下调皮质区APC蛋白表达,激活经典Wnt信号通路,进而发挥在去势雌性大鼠局灶性脑缺血损伤中的神经保护作用,为绝经激素治疗降低围绝经期妇女缺血性脑损伤的临床应用提供参考依据。
[Abstract]:Objective to investigate the effects of exogenous estrogen on the classical Wnt signaling pathway in ovariectomized female rats with middle cerebral artery occlusion (MCAO), and to explore the mechanism of neuroprotective effect of estrogen in focal cerebral ischemia.Methods 60 Wistar female rats of SPF grade 3 months old were randomly divided into 3 groups: sham operation group, model group, estrogen group (17 尾 -estradiol, subcutaneously injected with 300 渭 g/kg d), each group (20 rats).The mortality, neurological function score, body weight and serum E2 level of the three groups were compared 24 hours after MCAO operation to evaluate the volume of cerebral infarction and immunohistochemistry.The expression of Dickkopf associated protein -1 Dkk-1 in left cerebral cortex, adenomatoid polyposis adenomatous polyposis of cerebral cortex, 尾 -catenin and survivin were detected by Western blot.Results at 24 hours after MCAO operation, the mortality of rats in sham operation group, model group and estrogen group were 0 40 / 20 and 20 / 20 respectively. The neurological function score of estrogen group was higher than that of model group (P 0.05). There was no significant difference in mortality between model group and estrogen group (蠂 ~ (21) 1.905 P 0.168).The cerebral infarction volume in estrogen group ([255.43 卤51.43] mm ~ (-3)) was significantly higher than that in model group ([490.75 卤93.38] mm ~ (3)).After 6 weeks of supplementation of exogenous estrogen, 24 hours after MCAO operation,The results of immunohistochemistry showed that the expression level of Dkk-1 protein in model group was higher than that in other two groups, the difference was statistically significant (P < 0.05), and the expression level of APC protein in model group was higher than that in other two groups.The level of 尾 -catenin in estrogen group was higher than that in model group (P 0.05), but there was no significant difference between estrogen group and sham operation group (P 0.05), and the expression of Survivin protein in estrogen group was higher than that in model group (P < 0.05).Western blotting showed that the expression of DKK-1 protein in estrogen group was significantly lower than that in model group at 24 hours after MCAO operation, the expression of APC protein in estrogen group was lower than that in model group, and the expression of 尾 -catenin in estrogen group was higher than that in model group.The expression of Survivin protein in estrogen group was higher than that in model group (P < 0.05).Conclusion supplementation of exogenous estrogen can activate the classical Wnt signaling pathway by down-regulating the expression of APC protein in the cortical area and thus play a neuroprotective role in focal cerebral ischemia injury in ovariectomized female rats.To provide reference for the clinical application of menopausal hormone therapy to reduce ischemic brain injury in perimenopausal women.
【学位授予单位】：南京医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R-332;R711.75

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