不同年龄大鼠神经系统tau蛋白的表达特性

通过研究不同年龄组大鼠脑组织中微管相关蛋白tau的表达特性和磷酸化位点的差异，为阿尔茨海默病（AD）脑组织中tau蛋白的研究提供资料。将大鼠分为胎鼠、新生鼠、成年鼠和老年鼠4组，取各组大鼠的脑组织制成匀浆，用免疫印迹法检测各组tau蛋白的分子量范围及磷酸化状态。结果发现非磷酸化依赖性抗tau抗体R134d的免疫显色结果显示胎鼠和新生鼠主要含低分子量（14.2～28.8ku）tau蛋白；成年鼠除在脊索中显示高分子量tau（67.5～96.6ku）外，大脑灰质和白质中的tau蛋白主要集中在中分子量（28.8～42.7ku）范围；老年鼠的灰质、白质和脊索中均含高分子量tau蛋白，且在灰质和白质组分中中分子量tau的含量比成年组显著增高。Tau-1的显色性质与R134d相似。PHF-1和M4只在胎鼠和新生鼠显带。认为大鼠神经系统tau蛋白的表达性质及其磷酸化状态随年龄增长而显著不同。

Developmentally Regulated Expression of tau Proteinin Normal Rat Neural System

To study the difference in expression and phosphorylation of tau in normal rat neural system and therefore to provide information for Alzheimer disease (AD) studies on tau protein in brain, the brain gray matter, white matter or spinal cord from fetal, neonatal, adult and aged rats were isolated and homogenized, the supernatants were used for the analysis of expression and phosphorylation of tau by Western blotting. The results showed that in the fetal and neonatal rats only low molecular weight tau ranged from 14.2 to 28.8 ku were detected. On the other hand, middle (28 8-42 7 ku) and high(67 5-96 6 ku)molecular weight tau were seen in the adult and aged rats. The monoclonal antibody tau 1 reacted with all the isoforms of tau detected by R 134d that was supposed to bind to total tau. M4 and PHF 1 epitop phosphorylated tau were only determined in the fetal and neonatal, but not in the adult and aged rat neural system. The expression and phosphorylation of tau from central neural system were developmentally regulated, and phosphorylation of tau at M4 and PHF 1 epitop was not detected in normal condition.