In Vitro Tauopathy Model for Traumatic Brain Injury

 描述(申请人提供)：在反复轻度人类创伤性脑损伤患者和单一严重脑损伤后多年的患者中，广泛存在含有tau的神经原纤维缠结和A斑块病理。该项目的总体目标是建立一种新的体外脑损伤模型，以阐明将机械性神经元损伤与tau异常联系起来的细胞内通路。为了实现这一目标，我们将检验机械力导致神经元损伤导致tau过度磷酸化的中心假设，从而导致随后的tau错误定位和tau介导的突触缺陷。我们将追求两个特定的目标：在目标1中，我们确定了机械损伤导致树突棘中tau介导的形态缺陷的细胞机制。神经元将使用三种TBI方案进行拉伸，以模拟一次严重的TBI、反复的轻伤和炸弹冲击波。我们将确定由拉伸方案导致的tau错误定位是否取决于tau的过度磷酸化、tau激酶(CDK5和Gsk3)的激活以及A寡聚体的产生。我们还将测试tau和fyn在神经元损伤引起的脊柱丢失中的作用。在目标2中，我们将阐明机械损伤导致树突棘中tau介导的功能缺陷的细胞机制。我们将在我们的体外模型中描述机械损伤导致的突触前和/或突触后的缺陷，并将确定这些缺陷是否由内源性tau、tau过度磷酸化、A寡聚体的产生和钙调神经磷酸酶的激活所介导。这将是 是第一个可以复制DAI和tau异常的体外脑损伤模型。利用这个新的模型，我们将在细胞水平上阐明tau介导的TBI、AD和FTD之间的联系，为TBI的研究开辟一个新的领域。

 DESCRIPTION (provided by applicant): Widespread tau-containing neurofibrillary tangles and A plaque pathologies are present in the brains of patients with repetitive mild human traumatic brain injuries (TBI) and of patients many years after a single severe TBI. The overall goal of the proposed project is to build a novel in vitro TBI model in order to clarify the intracellular pathways that link mechanical neuronal injuries to tau abnormalities. To achieve this goal, we will test the central hypothesis that neuronal injuries caused by mechanical forces lead to tau hyperphosphorylation, which induces subsequent tau mislocalization and tau-mediated synaptic deficits. We will pursue two Specific aims: In Aim 1, we determine the cellular mechanism underlying mechanical injury- induced tau-mediated morphological deficits in dendritic spines. Neurons will be stretched using three TBI protocols to mimic one single severe TBI, repeated mild injuries and bomb blast waves. We will determine whether the tau mislocalization caused by the stretching protocols depends upon tau hyperphosphorylation, activation of tau kinases (CDK5 and GSK3) and the production of A oligomers. We will also test the roles of tau and Fyn in spine loss caused by neuronal injuries. In Aim 2, we will clarify the cellular mechanism underlying mechanical injury-induced tau-mediated functional deficits in dendritic spines. We will characterize pre- and/or post-synaptic deficits caused by mechanical injuries in our in vitro model and will determine whether these deficits are mediated by endogenous tau, tau hyperphosphorylation, the production of A oligomers and the activation of calcineurin. This will be the first in vitro TBI model that can replicate DAI and tau abnormalities. Using this novel model, we will clarify the tau-mediated link between TBI, AD, and FTD at a cellular level, opening a new area to the field of TBI research.