Nuydens R, De Jong M, Nuyens R, Cornelissen F, Geerts H
Department of Cellular Physiology, Janssen Research Foundation, Beerse, Belgium.
Neurobiol Aging. 1995 May-Jun;16(3):465-75; discussion 475-7. doi: 10.1016/0197-4580(94)00166-x.
Neurofibrillary tangles in Alzheimer's disease brain consist mainly of abnormally phosphorylated tau proteins organised in paired helical filaments. Induction of tau phosphorylation in living neurons by hyperstimulation is monitored by specific monoclonal antibodies, such as AT-8 and PHF-1. By quantitative immunocytochemistry, we show that aberrant phosphorylation at the Ser199/Ser202 epitope (AT-8) and at the Ser 396 epitope (PHF-1) are moderately induced, proportionally to the degree of kinase stimulation. Whereas AT8 expression is prominent after 48 h, cell death becomes significant at 72 h and is related to the degree of stimulation and the expression level of aberrant tau phosphorylation. Time-lapse videomicroscopy of individual neuroblastoma cells suggest that hyperstimulation leads to a form of morphological over-differentiation. Immediately before cell death, some cells tend to display some features of mitosis. The data suggest a strong correlation between the expression of specific PHF-epitopes and subsequent cell death. The extended time scale of toxicity in this model may be appropriate to study in more detail the steps leading to aberrant phosphorylation associated neurotoxicity.
阿尔茨海默病大脑中的神经原纤维缠结主要由异常磷酸化的tau蛋白组成，这些蛋白排列成双螺旋丝。通过特定的单克隆抗体，如AT-8和PHF-1，监测过度刺激在活神经元中诱导的tau磷酸化。通过定量免疫细胞化学，我们发现Ser199/Ser202表位（AT-8）和Ser 396表位（PHF-1）的异常磷酸化与激酶刺激程度成比例地适度诱导。虽然AT8表达在48小时后显著，但细胞死亡在72小时时变得显著，且与刺激程度和异常tau磷酸化的表达水平相关。对单个神经母细胞瘤细胞的延时视频显微镜观察表明，过度刺激会导致一种形态过度分化的形式。就在细胞死亡前，一些细胞倾向于表现出有丝分裂的一些特征。数据表明特定PHF表位的表达与随后的细胞死亡之间存在很强的相关性。该模型中延长的毒性时间尺度可能适合更详细地研究导致异常磷酸化相关神经毒性的步骤。
