目的:探讨在体转染GSK-3β对tall蛋白在PHF-1位点磷酸化的影响。方法:21只大鼠随机分为GSK-3β转染组、空载体组和空白对照组3组:0.1μl/3μl GSK-3β-HA质粒和空载体分别注射入大鼠大脑,对照组大鼠不作处理,应用免疫印迹和免疫组织化学检测GSK-3β的表达,并应用磷酸化位点特异性抗体PHF-1检测tau蛋白的磷酸化水平。结果:转染48h后,GSK-3β-HA表达在转染组;并且在转染区域的神经元内异常过度磷酸化tau蛋白(在PHF-1表位)聚积;异常过度磷酸化的tau蛋白与GSK-3β共定位。结论:在体转染GSK-3β引起导致神经退行性疾病发生机制相关的tau蛋白异常过度磷酸化,这进一步证明了GSK-3β是tau蛋白异常过度磷酸化的一个关键激酶,并且可作为一个防治与tau相关的神经退行性疾病的靶点。
AIM: To probe into tau hyperphosphorylation at PHF - 1 sites induced by glycogen synthase kinase - 3β (GSK- 3β) in vivo. METHODS: Twenty - one rats were randomly allocated to three groups as follows: GSK - 3β transfection group, vector group and control group; 0.1 μg/3μL GSK - 3β- HA plasmid or vector was injected bilaterally into cerebrum of the rats respectively, rats without injection were controls. Westem blotting and immunohistocbemical staining of cortex were carried out to detect the expression of GSK - 3β - HA plasmid and tau phosphorylation using phosphorylation - dependent tau antibody PHF- 1.RESULTS: After transfeetion with GSK-3β- HA for 48 h, GSK- 3β- HA was expressed in GSK- 3β transfection group; and hyperphosphorylated tau at PHF- 1 sites accumulated in neurons in the trarisfected areas. The hyperphosphorylated tau colocalized largely with GSK- 3β expressed by the transfected GSK-3β plasmid. CONCLUSIONS: Transfection with GSK-3β in vivo can induce tau hyperphosphorylation involving the pathogenesis of neurodegenerative disorders. These data further prove that GSK - 3β is a key kinase to induce tau hyperphosphorylation and may be a therapeutic target for tauopathy - related neurodegenerative diseases.