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。 阿尔茨海默病的进行性导致神经病理 改变了末期AD的特征，因为一些较早的、未知的 效应器启动一系列神经退行性事件(即， 级联)，包括通过合成和激活小胶质细胞 白细胞介素1(IL-1)的释放达到或超过所需的阈值水平 通过过度表达和释放S100β激活星形胶质细胞， 刺激神经突起的生长并增加细胞内的 钙，II)诱导β-淀粉样蛋白的过度合成和加工 前体蛋白(β-APP)，从而直接或间接 导致神经退行性改变，包括营养不良的轴突生长， 细胞外β-淀粉样蛋白沉积和钙依赖增加 最终导致神经元功能障碍和死亡的神经细胞功能。 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促进小胶质细胞的激活 在这样做的过程中，诱导IL-1的慢性过度表达，从而自我 我们提出的神经退行性级联的传播。 对这个假设中的细胞和分子事件的检查 神经退行性级联在人类和动物研究中较难获得 而不是体外实验。在我们的实验中， 我们将i)建立诱导IL-1所需的阈值水平- 和基于S100测试版的行动，ii)确定绝对 IL-1和S100β暴露水平与持续时间的关系，III)评估 IL-1和S100β在细胞和分子上的潜在相互作用 事件，以及四)评估IL-1的多能性 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， IL-1诱导星形胶质细胞活化和过度表达的结果 S100β的表达，或IL-1诱导的星形胶质细胞过表达 神经元中的β-APP和其他尚未被识别的事件或分子。 除了提供对我们的假设的更直接的研究之外 自传播级联过程中的参与 阿尔茨海默病的神经病理改变及阻断IL-1作用的治疗 体外试验可能会带来新的治疗策略。

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.