INTEGRATION OF GLIAL AND NEURONAL MECHANISMS IN CELL CULTURE

在这个项目中，我们将使用体外策略来检验我们的假设 AD的进行性导致神经病理学上的 改变终末期AD的特征，因为一些早期的，未知的 效应子引发一系列神经变性事件（即，一 级联），包括小胶质细胞的激活与合成， 白细胞介素-1（IL-1）的释放达到或高于所需的阈值水平 i）通过S100 β的过表达和释放激活星形胶质细胞， 刺激神经突的生长， 钙，ii）诱导β-淀粉样蛋白的过度合成和加工 前体蛋白（β-APP），从而iii）直接或间接 导致神经退行性变化，包括营养不良的神经突生长， 细胞外β-淀粉样蛋白沉积，以及钙依赖性 神经元细胞的功能，最终导致神经元功能障碍和死亡。 基于IL-1的体内作用的潜在后果，特别是细胞 死亡和P-淀粉样蛋白沉积，可以传播小胶质细胞的激活 并且，在这样做的过程中，诱导IL-1的慢性过度表达，从而自 我们提出的神经退行性级联的传播。 对本研究中假设的细胞和分子事件的检查 在人类和动物研究中，神经变性级联较难获得 比体外实验更好。在我们的实验中， 我们将i）建立诱导IL-1所需的阈值水平， 和S100 β为基础的行动，ii）确定绝对的重要性 水平与暴露于IL-1和S100 β的持续时间，iii）评估 IL-1和S100 β对细胞和分子的潜在相互作用 iv）评估IL-1的多能性，如直接免疫反应中所反映的， 神经元和星形胶质细胞的变化以及任一神经元的间接变化， 由于IL-1诱导的星形胶质细胞活化和过度表达， 或在星形胶质细胞中由于IL-1诱导的过度表达而引起的 β-APP和其他尚未识别的事件或神经元中的分子。 除了提供更直接的研究，我们的假设， 参与一个自蔓延级联的进展， AD的神经病理学变化，阻断IL-1作用的治疗 可能导致新的治疗策略。

In this project we will use in vitro strategies to examine our hypothesis that the progressive nature of AD results in the neuropathological changes characteristic of end-stage AD because some earlier, unknown effector initiates a series of neurodegenerative events (i.e., a cascade), that includes activation of microglia with synthesis and release of interleukin-1 (IL-1) at or above a threshold level necessary to: i) activate astrocytes with overexpression and release of S100beta, which stimulates growth of neurites and increases in intracellular calcium, ii) induce excessive synthesis and processing of beta-amyloid precursor protein (beta-APP), and thereby iii) directly or indirectly cause neurodegenerative changes, including dystrophic neurite outgrowth, extracellular beta-amyloid deposition, and increases in calcium-dependent neuronal cell functions that culminate in neuronal dysfunction and death. Potential consequences of IL-1-based actions in vivo, especially cell death and P-amyloid deposits, could propagate activation of microglia and, in so doing, induce chronic overexpression of IL-1 thus self- propagation of our proposed neurodegenerative cascade. Examination of the cellular and molecular events hypothesized in this neurodegenerative cascade are less accessible in human and animal studies than in vitro experiments. In our experiments, we will i) establish threshold levels necessary for induction of IL-1- and S100beta-based actions, ii) determine the importance of the absolute level vs the duration of exposure to IL-1 and S100beta, iii) evaluate potential interactions of IL-1 and S100beta on cellular and molecular events, and iv) assess the pluripotency of IL-1 as reflected in direct changes in neurons and astrocytes and indirect changes in either neurons, as a result of IL-1-induced activation of astrocytes and overexpression of S100beta, or in astrocytes as a result of IL-1-induced overexpression of beta-APP and other as-yet-unrecognized events or molecules in neurons. In addition to providing more direct study of our hypothesis of the involvement of a self-propagating cascade in the progression of neuropathological changes in AD, treatments to block the effects of IL-1 in vitro may lead to new therapeutic strategies.