GLIAL/NEURONAL INTERACTIONS IN NEURODENGENERATION

进行性神经元变性是认知功能障碍的基础， 阿尔茨海默病（AD）。 神经炎斑块，包括沉积物， β-淀粉样蛋白（BetaA 4）被反应性胶质细胞包围， 神经元是AD的标志 鉴于星形胶质细胞（神经胶质细胞）的作用， 在调节神经元的发育和生存能力方面， 一个项目是检验一个假设，即异常的神经胶质-神经元相互作用 通过改变神经元Ca 2+稳态来影响神经变性。 一 一系列实验将利用16三体（Ts 16）小鼠， 含有一个额外的16号染色体拷贝，在该染色体上有一个基因， 编码β-淀粉样前体蛋白（BetaAPP）和小鼠同源物 可能的家族性AD基因 为了测试是否增加了 一个或多个16号染色体基因的表达影响神经元特性， 星形胶质细胞和星形胶质细胞衍生物质对存活力的影响 海马神经元的结构将在体外进行研究， 培养Ts 16和整倍体神经元和星形胶质细胞的各种组合， 通过检测Ts 16和整倍体星形胶质细胞条件培养基对 神经元的特性，并通过添加各种假定的神经胶质衍生的生长 因子及其对神经元培养物的中和抗体。 的 胞内Ca ~（2+）在神经元早死中的作用 将通过计算机辅助电离内部成像检查培养物。 利用荧光Ca ~（2+）测定Ts 16和整倍体神经元中的Ca ~（2+）水平 指示剂，呋喃-2。 第二系列实验将研究S100 Beta， Ca 2+结合蛋白在人脑中广泛分布， 在AD中。 据报道，S100 β具有神经营养和神经胶质双重作用。 促有丝分裂活性 为了验证过量的酒精 S100 β可能过度刺激神经元突起的形成，使神经元 更容易失去细胞内Ca 2+调节，培养 将在存在下研究来自正常小鼠的海马神经元 S100 β或抗S100 β抗体。 神经元活力和神经突 将对配置进行评估。 S100 β过表达对 星形胶质细胞的结构、功能和发育将在 从转基因S100 β小鼠培养的海马星形胶质细胞和 转基因S100 β小鼠脑的切片。 此外，监管 神经元和星形胶质细胞胞内CA 2+在S100 β的存在下， 通过Fura-2荧光成像进行研究。

Progressive neuronal degeneration underlies the cognitive dysfunction of Alzheimer's disease (AD). The neuritic plaque, consisting of deposits of Beta-amyloid (BetaA4) protein surrounded by reactive glia and degenerating neurons, is a hallmark of AD. Given the role of astrocytes (glial cells) in regulating the development and viability of neurons, the goal of this project is to test the hypothesis that abnormal glial-neuronal interactions influence neurodegeneration by altering neuronal Ca2+ homeostasis. One series of experiments will utilize the trisomy 16 (Ts16) mouse which contains an extra copy of chromosome 16, on which is located the gene coding for Beta-amyloid precursor protein (BetaAPP) and the mouse homolog of the putative familial AD locus. In order to test whether increased expression of one or more chromosome 16 genes affects neuronal properties, the effects of astrocytes and astrocyte-derived substances on the viability and structure of hippocampal neurons will be studied in vitro by co- culturing various combinations of Ts16 and euploid neurons and astrocytes, by examining effects of Ts16 and euploid astrocyte-conditioned medium on neuronal properties, and by adding various putative glial-derived growth factors and their neutralizing antibodies to the neuronal cultures. The role of intracellular Ca2+ in the premature death of Ts16 neurons in culture will be examined by computer-assisted imaging of ionized internal Ca2+ levels in Ts16 and euploid neurons using the fluorescent Ca2+ indicator, fura-2. A second series of experiments will study S100Beta, a Ca2+-binding protein widely distributed in brain in man, that is elevated in AD. S100Beta has been reported to have both neurotrophic and glial mitogenic activity. In order to test the hypothesis that excessive levels of S100Beta may overstimulate neuronal process formation, making the neuron more vulnerable to a loss of intracellular Ca2+ regulation, cultured hippocampal neurons from normal mice will be studied in the presence of S100Beta or anti-S100Beta antibodies. Neuronal viability and neurite configuration will be evaluated. The effects of S100Beta overexpression on astrocyte structure, function, and development will be investigated in cultured hippocampal astrocytes from transgenic S100Beta mice and in sections of transgenic S100Beta mouse brain. In addition, regulation of neuronal and astrocyte intracellular CA2+ in the presence of S100Beta will be studied by imaging of fura-2 fluorescence.