复方金思维对老年性痴呆模型大鼠海马神经元微管和Tau蛋白磷酸化相关酶类表达的影响

Effect of Jinsiwei on neuron microtubule in hippocampus and expression of Tau-protein phosphorylation related enzyme in rats with AD

关键词:  阿尔茨海默病  Tau蛋白  微管  金思维

Key words:  Alzheimer’s disease  Tau-protein  microtubule  GETO

摘要:

[目的]观察中药复方金思维对老年性痴呆(AD)模型大鼠海马CA1区神经元微管结构和Tau蛋白磷酸化相关酶类表达的影响。[方法]48只SD大鼠随机等分为假手术组、模型组、盐酸多奈哌齐组和金思维大、中、小剂量组。采用双侧脑室注射微量链脲佐菌素(STZ3mg/kg)建立拟AD大鼠模型,模型成功后,治疗组分别予盐酸多奈哌齐和金思维(分为3个不同剂量)进行3个月的治疗,模型组和假手术组给予等体积的双蒸水。行灌注固定,冰冻切片,取各组大鼠海马CA1区组织进行光镜和电镜观察,并进行糖原合成激酶3β(GSK-3β)、蛋白磷酸酶-1(PP-1)、蛋白磷酸酶-2A(PP-2A)的免疫组化染色。[结果]1)AD大鼠海马神经元微管结构出现明显的断裂或溶解现象,而用金思维治疗后这种现象得到明显改善。2)AD大鼠海马内的蛋白激酶GSK-3β明显增多、PP-1、PP-2A明显减少,金思维各剂量组上述酶类表达均接近至正常水平,与盐酸多奈哌齐组比较无差异。[结论]AD大鼠模型脑组织微管结构和Tau蛋白磷酸化相关酶类的表达发生异常,金思维可修复断裂或溶解的微管,使蛋白激酶和磷酸酶的表达接近至正常水平。

Abstract:

[Objective] To study the Jinsiwei(GETO)-induced changes in the ultrastructure of neuron microtubule in CAI region of hippocampus and the expression of enzymes related to phosphorylation of tau-proteins in AD rats. [Methods] Forty-eight SD rats were randomly divided into sham operation group, model group, donepezil group, the high, middle and low dosage of GETO group. AD was induced by intracerebroventricular administration of streptozotocin (ic-STZ). The GETO groups were treated with gastric perfusion of Jinsiwei in three different dosage for three months. Both the model group and sham group were given double distilled water. Three months later, intravascular fixative was injected into the rats. Tissue specimens for each group were harvested from the hippocampus CA1 area for light and electron microscopy studies. Cryostatsecions were studied with immunohistochemistry for glycogen synthase kinase 3β(GSK-3β), protein phosphatase-1 (PP-1), protein phosphatase-2A (PP-2A). [Results] The microtubules of hippocampus neurons of AD showed prominent changes of fragmentation and dissolution, while treatment with GETO can significantly ameliorate these changes. The hippocampus neurons of AD rats showed significantly intracellular increase in the tau-phosphokinase, GSK-3β and decrease in the tau-dephosphrylating enzymes, PP-1 and PP-2A. GETO can also restore the expression of enzymes to normal levels,and there was no difference between the Donepezil group and GETO groups. [Conclusions] Brain tissue of AD rats shows changes in microtubules and enzymes related to phosphorylation of tau proteins. GETO can improve all the abnormalities of AD rats.