Tau蛋白过度磷酸化对脑淀粉样蛋白生成的影响

Effect of hyperphosphorylated tau protein on the formation of brain amyloid

目的研究tau蛋白过度磷酸化对脑淀粉样蛋白生成的影响。方法用蛋白磷酸酯酶抑制剂冈田酸(OA)在大鼠侧脑室内注射,每天1次连续8周。用Morris水迷宫和免疫组化方法观察OA组大鼠行为学改变、神经原纤维缠结及淀粉样蛋白的表达;并与对照组比较。结果与对照组相比,OA组大鼠Morris水迷宫平均潜伏期显著延长,学习获取能力较差,空间记忆能力衰退。OA组大鼠的海马CA1区、CA3区、CA4区、齿状回、大脑皮质出现tau蛋白磷酸化,神经原纤维缠结;大脑皮质及海马CA1区、CA3区、齿状回等部位出现β淀粉样蛋白沉积。结论Tau蛋白过度磷酸化可以增加脑部淀粉样蛋白的沉积。

Objective To explore the effect of hyperphosphorylated tau protein on the formation of brain amyloid. Methods Okadaic acid was injected into lateral ventricle of rats, once a day for eight weeks. The place navigation and spatial probe ability of rats were assessed by Morris water maze. Immunohistochemistry techniques were used to detect the expressions of neurofibrillary tangles and amyloid. Results In the Okadaic acid group, the spatial learning and memory abilities of rats were significantly impaired. The mean incubation period of Morris water maze was longer than control group. The accumulation of neurofibrillary tangles and plenty of β-amyloid positive cells were detected in hippocampus CA1, CA3 and CA4 regions, dentate gyrus and cortex. Deposition of β-amyloid was observed in hippecampus CA1 and CA3 regions, dentate gyrus and cortex. Conclusion The hyperphosphorylated tau protein may significantly increase deposition of amyloid in brain.