Aging and Dementia: Cholinergic neuron biochemistry

描述（由申请人提供）： 这项工作旨在建立在我们对阿尔茨海默病中tau变得异常的机制以及导致缠结形成和细胞死亡的关键因素的日益了解的基础上。现在，我们试图测试新的具体假设负责这些事件的机制。tau蛋白的酪氨酸磷酸化似乎是AD中非常早期的事件，并且负责这些磷酸化的激酶将是该应用的主要焦点。还将检查可以激活这些激酶的机制，以确定是否可以证明与病理学的关联。关于APP的明显AD特异性磷酸化和Pin 1结合的新数据已经提出了检查APP加工和tau病理学变化之间关系的方法。具体目标是：1.我们将检验以下假设：Y18和/或394上的tau磷酸化是AD中tau构象变化产生的候选者。Fyn和abl是可能负责这些磷酸化的激酶，这些蛋白质与tau病理学的关联将被详细研究。2.其他人已经提出了Abeta沉积触发src家族激酶（和tau的酪氨酸磷酸化）活化的假设，并且这将在AD脑中以严格的方式进行测试。使用与目的1中所用相同的组织，通过免疫细胞化学检查pY 18、fyn和abl与Abeta的蓄积。还将检查Abeta对tau蛋白酪氨酸磷酸化的影响可能通过小胶质细胞产生TNF α间接介导的可能性。3. tau与fyn和abl的相互作用将在培养细胞中进一步检查。将用特定的tau亚型沿着fyn或ab 1转染细胞。将测试tau酪氨酸磷酸化引起可能对tau亚型组成敏感的构象变化的假设。4.我们将测试这一假设，即APP加工的变化可以诱导细胞培养系统中tau构象和磷酸化的变化，所述细胞培养系统被选择为具有多种tau亚型组成。5. Pin 1与磷酸化的tau和磷酸化的APP结合，并且这两个位点在AD脑中都被磷酸化。Pin 1参与tau构象变化并可能参与APP加工修饰的假设将得到验证。这项工作将有助于了解AD的过程，并有助于导致新的治疗策略。

DESCRIPTION (provided by applicant): This work is designed to build on our growing understanding of the mechanism by which tau becomes abnormal in Alzheimer's disease, and the critical factors that lead to tangle formation and cell death. We now seek to test new specific hypotheses regarding the mechanisms responsible for these events. Tyrosine phosphorylation of tau seems to be a very early event in AD, and the kinases responsible for these phosphorylations will be a major focus of this application. Mechanisms that can activate these kinases will also be examined to determine if associations with pathology can be demonstrated. New data on an apparent AD-specific phosphorylation of APP and the binding of Pin1 have suggested approaches to examination of the relationship between changes in APP processing and tau pathology. The specific aims are: 1. We will test the hypothesis that phosphorylation of tau on Y18 and/or 394 are candidates for production of conformational changes in tau in AD. Fyn and abl are the kinases that may be responsible for these phosphorylations, and the association of these proteins with tau pathology will be examined in detail. 2. The hypothesis that Abeta deposition triggers activation of src family kinases (and tyrosine phosphorylation of tau) has been proposed by others, and this will be tested in a rigorous fashion in the AD brain. The accumulation of pY18, fyn and abl with Abeta will be examined by immunocytochemistry using the same tissues employed in Aim 1. The possibility that Abeta effects on tyrosine phosphorylation of tau might be indirectly mediated through microglial production of TNF alpha will also be examined. 3. The interaction of tau with fyn and abl will be further examined in cultured cells. Cells will be transfected with specific tau isoforms along with fyn or abl. The hypothesis that tyrosine phosphorylation of tau causes conformational changes that may be sensitive to tau isoform composition will be tested. 4. We will test the hypothesis that changes in APP processing can induce changes in tau conformation and phosphorylation in cell culture systems selected to have a variety of tau isoform compositions. 5. Pin1 binds to both phosphorylated tau and phosphorylated APP, and both sites are phosphorylated in the AD brain. The hypothesis that Pin1 is involved in conformation changes of tau and perhaps in modifying APP processing will be tested. This work will help understand the process of AD, and help lead to new therapeutic strategies.