Calcineurin and inflammatory signaling processes in aging and Alzheimer's Disease

描述（由申请人提供）：阿尔茨海默病（AD）是一种破坏性和不可逆的神经系统疾病，逐渐改变人格和行为，并破坏认知功能。AD每年花费超过1000亿美元，也是美国最昂贵的疾病之一。近年来，抗炎剂已成为延迟AD症状发作的有前途的化合物。然而，我们对大脑中神经免疫/炎症（im/inf）信号传导机制的理解仍然不完整。钙调蛋白依赖性蛋白磷酸酶，钙调磷酸酶，在淋巴细胞和其他细胞类型的im/inf信号级联中起着关键作用，但很少考虑在神经组织中的类似作用。在过去的一年中，我们发现神经元-神经胶质细胞共培养物中的钙调磷酸酶激活足以重现与衰老和AD一致的im/inf反应的几个组成部分，包括星形胶质细胞激活和诱导许多im/inf相关基因级联。我们还观察到AD模型小鼠中淀粉样蛋白沉积物周围活化的星形胶质细胞中钙调神经磷酸酶的显著和选择性上调。因此，本项目的长期目标是检验钙调神经磷酸酶是激活与AD相关的im/inf信号传导过程的关键组分的假设。前两个目标将测试是否激活钙调磷酸酶和/或钙调磷酸酶依赖性转录因子，NFAT是必要的im/inf信号在星形胶质细胞。在存在或不存在有效的钙调磷酸酶和NFAT抑制剂的情况下，将生物学相关的炎症介质递送至星形胶质细胞特异性培养物。将采用蛋白质印迹、RT-PCR和细胞因子阵列评估im/inf标志物的诱导。还将检查星形胶质细胞中钙调神经磷酸酶激活的潜在Ca 2+来源，沿着钙调神经磷酸酶通过上调这些Ca 2+来源来放大其自身活性的可能性。目的三将使用细胞分级分离，免疫沉淀，蛋白质印迹，磷酸酶活性测定，免疫组织化学和原位杂交，定性和定量评估AD脑标本和/或AD啮齿动物模型中钙调神经磷酸酶信号转导的变化。这些研究的完成将大大增加我们对钙调神经磷酸酶在神经炎症和AD中作用的认识，并可能导致这种疾病和其他神经炎症突出的退行性疾病的新治疗策略的发展。

DESCRIPTION (provided by applicant): Alzheimer's disease (AD) is a devastating and irreversible neurological disease that progressively alters personality and behavior, and destroys cognitive function. With an annual price tag exceeding 100 billion dollars, AD is also one of the nation's most costly diseases. In recent years, anti-inflammatory agents have emerged as promising compounds for delaying the onset of AD symptoms. Yet, our understanding of the mechanisms underlying neuro-immune/inflammatory (im/inf) signaling in the brain remains incomplete. The Ca2+/calmodulin dependent protein phosphatase, calcineurin, plays a critical role in im/inf signaling cascades in lymphocytes and other cell types, but has received little consideration for a similar role in nervous tissue. In the past year, we found that calcineurin activation in neuron-glia co-cultures was sufficient for recapitulating several components of the im/inf response found consistently with aging and AD, including astrocyte activation and the induction of numerous im/inf-related gene cascades. We also observed a marked and selective upregulation of calcineurin in activated astrocytes surrounding amyloid deposits in AD model mice. The long-term goal of this project is to therefore test the hypothesis that calcineurin is a critical component for the activation of im/inf signaling processes associated with AD. The first two aims will test whether activation of calcineurin and/or the calcineurin-dependent transcription factor, NFAT is necessary for im/inf signaling in astrocytes. Biologically relevant inflammatory mediators will be delivered to astrocyte- specific cultures in the presence or absence of potent calcineurin and NFAT inhibitors. The induction of im/inf markers will be assessed with Western blots, RT-PCR, and cytokine arrays. Potential Ca2+ sources for calcineurin activation in astrocytes will also be examined, along with the possibility that calcineurin amplifies its own activity by up-regulating these Ca2+ sources. Aim three will use cell fractionation, immunoprecipitation, Western blot, phosphatase activity assays, immunohistochemistry, and in situ hybridization to qualitatively and quantitatively assess changes in calcineurin signaling in AD brain specimens and/or in a rodent model of AD. Completion of these studies will greatly increase our knowledge of the role of calcineurin in neuroinflammation and AD, and may lead to the development of novel treatment strategies for this disease and other degenerative conditions where neuroinflammation is prominent.