A2AR活化在脑创伤后tau蛋白过度磷酸化中的作用与机制研究

摘要

Objective To explore the A2AR activation after traumatic brain injury mechanisms and the role of excessive tau protein phosphorylation.Methods With no specific mice experiment research of specific pathogens, position in the left parietal cortex in mice, by the method of controllable cortical against brain trauma model model, 15 min after injury in mice abdominal injection of A2AR specific inhibitors ZM241385 or use A2AR knockout mice, testing the brain neuron loss and tau protein phosphorylation level;Use specific agonists CGS21680 activate the original generation of nerve cells in the hippocampus and the A2AR human neuroblastoma cells, using immunocytochemistry and immunofluorescence test tua protein phosphorylation level of change, to observe axon transport function of mitochondria.Results Immunohistochemical results accumulation of optical density analysis showed that inhibition of A2AR activation can significantly reduce after cerebral trauma Ser404 tua protein loci phosphorylation levels, reduce excessive tua protein phosphorylation with nerve pathological change;A2AR activation after tua phosphorylation of proteins at a Ser404 site level increased significantly, nerve axons per unit length processes in the mitochondria number decreased significantly, resulting in axoplasmic transport dysfunction;To activate the original generation of nerve cells in the hippocampus and after the A2AR human neuroblastoma cells, tua protein phosphorylation Ser404 locus levels increased significantly.Conclusion A2AR activation after cerebral trauma has obvious influence on tua protein phosphorylation levels, may be a function by influencing the axoplasmic transport, eventually forming cognitive dysfunction.%目的 探讨A2AR活化在脑创伤后tau蛋白过度磷酸化中的作用与机制.方法 用无特定无特定病原体的小鼠进行实验研究,在小鼠左侧顶叶皮层位置,采应用可控皮质打击法建立脑创伤模型,在致伤后15 min于小鼠腹部注射A2AR特异性抑制剂ZM241385或使用A2AR基因敲除小鼠,检测各脑区神经元丢失情况及tau蛋白磷酸化水平;使用特异性激动剂CGS21680激活原代海马神经细胞及人神经母细胞瘤细胞的A2AR,用免疫细胞化学及免疫荧光技术检测tau蛋白磷酸化水平变化,观察轴突对线粒体的运输功能.结果 免疫组化结果积累光密度分析显示,抑制A2AR活化可以显著降低脑创伤后tau蛋白Ser404位点磷酸化水平,减轻tau蛋白过度磷酸化伴随的神经病理改变;A2AR活化后tau蛋白在Ser404位点的磷酸化水平明显升高,神经元轴突单位长度突起内线粒体数量明显减少,从而导致轴浆运输功能障碍;激活原代海马神经细胞及人神经母细胞瘤细胞的A2AR后,tau蛋白Ser404位点磷酸化水平明显升高.结论 脑创伤后A2AR活化对tau蛋白磷酸化水平有明显的影响,可能是通过影响轴浆运输功能,最终形成认知功能障碍.